From da9144b7b99a8ce0e0ea327f06fb9478e908202a Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Sun, 27 Aug 2023 18:57:54 +0800
Subject: [PATCH 01/59] Rename bot and implement basic greet, exit

---
 src/main/java/Duke.java | 23 +++++++++++++++++------
 1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 5d313334c..d0effdb99 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,10 +1,21 @@
+import java.util.Arrays;
+
 public class Duke {
+    final private static String BOT_NAME = "Python";
+    final private static int HORIZONTAL_LINE_LENGTH = 80;
+
+    private static void printHorizontalLine() {
+        char[] horizontalLine = new char[HORIZONTAL_LINE_LENGTH];
+        Arrays.fill(horizontalLine, '—');
+        System.out.println(new String(horizontalLine));
+    }
+    
     public static void main(String[] args) {
-        String logo = " ____        _        \n"
-                + "|  _ \\ _   _| | _____ \n"
-                + "| | | | | | | |/ / _ \\\n"
-                + "| |_| | |_| |   <  __/\n"
-                + "|____/ \\__,_|_|\\_\\___|\n";
-        System.out.println("Hello from\n" + logo);
+        printHorizontalLine();
+        System.out.printf("Hello! I am a short Java Bot %s!\n", BOT_NAME);
+        System.out.println("What can I do for you?");
+        printHorizontalLine();
+        System.out.println("Bye. See you again when you run the program again!");
+        printHorizontalLine();
     }
 }

From 75be7cef568c14b7d116010c030c1e2bf469e7ee Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 20:32:00 +0800
Subject: [PATCH 02/59] Echo the user given command, exit when "bye"

---
 src/main/java/Duke.java | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index d0effdb99..b844ccebb 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,9 +1,12 @@
 import java.util.Arrays;
+import java.util.Scanner;
 
 public class Duke {
     final private static String BOT_NAME = "Python";
     final private static int HORIZONTAL_LINE_LENGTH = 80;
 
+    final private static Scanner in = new Scanner(System.in);
+
     private static void printHorizontalLine() {
         char[] horizontalLine = new char[HORIZONTAL_LINE_LENGTH];
         Arrays.fill(horizontalLine, '—');
@@ -15,7 +18,17 @@ public static void main(String[] args) {
         System.out.printf("Hello! I am a short Java Bot %s!\n", BOT_NAME);
         System.out.println("What can I do for you?");
         printHorizontalLine();
-        System.out.println("Bye. See you again when you run the program again!");
-        printHorizontalLine();
+
+        String inputCommand;
+        do {
+            inputCommand = in.nextLine();
+            printHorizontalLine();
+            if (inputCommand.equals("bye")) {
+                System.out.println("Bye. See you again when you run the program again!");
+            } else {
+                System.out.println(inputCommand);
+            }
+            printHorizontalLine();
+        } while(!inputCommand.equals("bye"));
     }
 }

From afc511c819c8e3c670f78ccc7c0154c8111b68c6 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 20:39:07 +0800
Subject: [PATCH 03/59] Add indentation to responses

---
 src/main/java/Duke.java | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index b844ccebb..6c87ecf67 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -10,13 +10,13 @@ public class Duke {
     private static void printHorizontalLine() {
         char[] horizontalLine = new char[HORIZONTAL_LINE_LENGTH];
         Arrays.fill(horizontalLine, '—');
-        System.out.println(new String(horizontalLine));
+        System.out.println("\t" + new String(horizontalLine));
     }
     
     public static void main(String[] args) {
         printHorizontalLine();
-        System.out.printf("Hello! I am a short Java Bot %s!\n", BOT_NAME);
-        System.out.println("What can I do for you?");
+        System.out.printf("\tHello! I am a short Java Bot %s!\n", BOT_NAME);
+        System.out.println("\tWhat can I do for you?");
         printHorizontalLine();
 
         String inputCommand;
@@ -24,9 +24,9 @@ public static void main(String[] args) {
             inputCommand = in.nextLine();
             printHorizontalLine();
             if (inputCommand.equals("bye")) {
-                System.out.println("Bye. See you again when you run the program again!");
+                System.out.println("\tBye. See you again when you run the program again!");
             } else {
-                System.out.println(inputCommand);
+                System.out.println("\t" + inputCommand);
             }
             printHorizontalLine();
         } while(!inputCommand.equals("bye"));

From 332b3f4c8a83495047bf2eb6784a3c4e1c10e292 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 20:51:19 +0800
Subject: [PATCH 04/59] Add Python ASCII art

---
 src/main/java/Duke.java | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 6c87ecf67..8ea8dd669 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -5,6 +5,14 @@ public class Duke {
     final private static String BOT_NAME = "Python";
     final private static int HORIZONTAL_LINE_LENGTH = 80;
 
+    final private static String pythonASCIIArt =
+            "\t ____        _   _                 \n" +
+            "\t|  _ \\ _   _| |_| |__   ___  _ __  \n" +
+            "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\ \n" +
+            "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
+            "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
+            "\t       |___/                        ";
+
     final private static Scanner in = new Scanner(System.in);
 
     private static void printHorizontalLine() {
@@ -14,6 +22,7 @@ private static void printHorizontalLine() {
     }
     
     public static void main(String[] args) {
+        System.out.println(pythonASCIIArt);
         printHorizontalLine();
         System.out.printf("\tHello! I am a short Java Bot %s!\n", BOT_NAME);
         System.out.println("\tWhat can I do for you?");

From 1ebb2bff661c6854e27e803dd3b803bb111f5d00 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 21:11:04 +0800
Subject: [PATCH 05/59] Add Python emoji before response

---
 src/main/java/Duke.java | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 8ea8dd669..76e8af5cb 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -13,6 +13,7 @@ public class Duke {
             "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
             "\t       |___/                        ";
 
+    final private static String pythonEmoji = "\uD83D\uDC0D";
     final private static Scanner in = new Scanner(System.in);
 
     private static void printHorizontalLine() {
@@ -24,8 +25,8 @@ private static void printHorizontalLine() {
     public static void main(String[] args) {
         System.out.println(pythonASCIIArt);
         printHorizontalLine();
-        System.out.printf("\tHello! I am a short Java Bot %s!\n", BOT_NAME);
-        System.out.println("\tWhat can I do for you?");
+        System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", pythonEmoji, BOT_NAME);
+        System.out.printf("\t%s: What can I do for you?\n", pythonEmoji);
         printHorizontalLine();
 
         String inputCommand;
@@ -33,9 +34,9 @@ public static void main(String[] args) {
             inputCommand = in.nextLine();
             printHorizontalLine();
             if (inputCommand.equals("bye")) {
-                System.out.println("\tBye. See you again when you run the program again!");
+                System.out.printf("\t%s: Bye. See you again when you run the program again!\n", pythonEmoji);
             } else {
-                System.out.println("\t" + inputCommand);
+                System.out.printf("\t%s: %s\n", pythonEmoji, inputCommand);
             }
             printHorizontalLine();
         } while(!inputCommand.equals("bye"));

From 111d8a1c586dc9c23c1fe929eec3cbb3df12c4e3 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 21:39:58 +0800
Subject: [PATCH 06/59] Store commands and display if requested

---
 src/main/java/Duke.java | 17 +++++++++++++++--
 1 file changed, 15 insertions(+), 2 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 76e8af5cb..f0d888bb8 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -1,4 +1,6 @@
+import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.List;
 import java.util.Scanner;
 
 public class Duke {
@@ -14,6 +16,8 @@ public class Duke {
             "\t       |___/                        ";
 
     final private static String pythonEmoji = "\uD83D\uDC0D";
+
+    final static private List<String> commandsList = new ArrayList<>();
     final private static Scanner in = new Scanner(System.in);
 
     private static void printHorizontalLine() {
@@ -33,10 +37,19 @@ public static void main(String[] args) {
         do {
             inputCommand = in.nextLine();
             printHorizontalLine();
-            if (inputCommand.equals("bye")) {
+            switch (inputCommand) {
+            case "bye":
                 System.out.printf("\t%s: Bye. See you again when you run the program again!\n", pythonEmoji);
-            } else {
+                break;
+            case "list":
+                System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, commandsList.size());
+                for(int taskNo = 1; taskNo <= commandsList.size(); taskNo++) {
+                    System.out.printf("\t\t\t%d. %s\n", taskNo, commandsList.get(taskNo - 1));
+                }
+                break;
+            default:
                 System.out.printf("\t%s: %s\n", pythonEmoji, inputCommand);
+                commandsList.add(inputCommand);
             }
             printHorizontalLine();
         } while(!inputCommand.equals("bye"));

From 0093f07a68f6ef577d48c4fbabfd25c8a4a5a3c6 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 23:12:56 +0800
Subject: [PATCH 07/59] Add task class

---
 src/main/java/Task.java | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)
 create mode 100644 src/main/java/Task.java

diff --git a/src/main/java/Task.java b/src/main/java/Task.java
new file mode 100644
index 000000000..479b5b894
--- /dev/null
+++ b/src/main/java/Task.java
@@ -0,0 +1,25 @@
+public class Task {
+    protected String description;
+    protected boolean isDone;
+
+    public Task(String description) {
+        this.description = description;
+        this.isDone = false;
+    }
+
+    public String getStatusIcon() {
+        return (isDone ? "X" : " "); // mark done task with X
+    }
+
+    public String getDescription() {
+        return description;
+    }
+
+    public boolean isDone() {
+        return isDone;
+    }
+
+    public void setDone(boolean done) {
+        isDone = done;
+    }
+}

From 8f17b2472e623bec0c3d9b91420070e468fa623c Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 23:13:20 +0800
Subject: [PATCH 08/59] Allow mark and unmark of tasks

---
 src/main/java/Duke.java | 60 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 51 insertions(+), 9 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index f0d888bb8..c3b47fa2f 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -17,7 +17,7 @@ public class Duke {
 
     final private static String pythonEmoji = "\uD83D\uDC0D";
 
-    final static private List<String> commandsList = new ArrayList<>();
+    final static private List<Task> taskList = new ArrayList<>();
     final private static Scanner in = new Scanner(System.in);
 
     private static void printHorizontalLine() {
@@ -33,25 +33,67 @@ public static void main(String[] args) {
         System.out.printf("\t%s: What can I do for you?\n", pythonEmoji);
         printHorizontalLine();
 
-        String inputCommand;
+        String inputLine;
         do {
-            inputCommand = in.nextLine();
+            inputLine = in.nextLine();
+            String inputCommand = inputLine.split(" ")[0];
             printHorizontalLine();
             switch (inputCommand) {
             case "bye":
                 System.out.printf("\t%s: Bye. See you again when you run the program again!\n", pythonEmoji);
                 break;
             case "list":
-                System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, commandsList.size());
-                for(int taskNo = 1; taskNo <= commandsList.size(); taskNo++) {
-                    System.out.printf("\t\t\t%d. %s\n", taskNo, commandsList.get(taskNo - 1));
+                System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, taskList.size());
+                for(int taskNo = 1; taskNo <= taskList.size(); taskNo++) {
+                    System.out.printf("\t\t\t%d. [%s] %s\n",
+                            taskNo, taskList.get(taskNo - 1).getStatusIcon(),
+                            taskList.get(taskNo - 1).getDescription());
                 }
                 break;
+            case "mark": {
+                int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+                if (taskNo > taskList.size()) {
+                    System.out.printf("\t%s: Are you from the future?\n", pythonEmoji);
+                    break;
+                }
+                if (taskList.get(taskNo - 1).isDone()) {
+                    System.out.printf("\t%s: Are you from the past?\n", pythonEmoji);
+                    System.out.printf("\t\tTask: \"%s\" is already done!!!\n",
+                            taskList.get(taskNo - 1).getDescription());
+                    break;
+                }
+                taskList.get(taskNo - 1).setDone(true);
+                System.out.printf("\t%s: Good job completing the task!\n", pythonEmoji);
+                System.out.printf("\t\t\t[%s] %s\n",
+                        taskList.get(taskNo - 1).getStatusIcon(),
+                        taskList.get(taskNo - 1).getDescription());
+                break;
+            }
+            case "unmark": {
+                int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+                if (taskNo > taskList.size()) {
+                    System.out.printf("\t%s: Are you from the future?\n", pythonEmoji);
+                    break;
+                }
+                if (!taskList.get(taskNo - 1).isDone()) {
+                    System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", pythonEmoji);
+                    System.out.printf("\t\tTask: \"%s\" is already sitting idle. Get started...!!!\n",
+                            taskList.get(taskNo - 1).getDescription());
+                    break;
+                }
+                taskList.get(taskNo - 1).setDone(false);
+                System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", pythonEmoji);
+                System.out.printf("\t\t\t[%s] %s\n",
+                        taskList.get(taskNo - 1).getStatusIcon(),
+                        taskList.get(taskNo - 1).getDescription());
+                break;
+            }
             default:
-                System.out.printf("\t%s: %s\n", pythonEmoji, inputCommand);
-                commandsList.add(inputCommand);
+                System.out.printf("\t%s: %s\n", pythonEmoji, inputLine);
+                Task task = new Task(inputLine);
+                taskList.add(task);
             }
             printHorizontalLine();
-        } while(!inputCommand.equals("bye"));
+        } while(!inputLine.equals("bye"));
     }
 }

From 4cf5d1e44c98ae6ec8101b934b8dd2418107f9c0 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 23:22:15 +0800
Subject: [PATCH 09/59] Rename taskList to tasks

---
 src/main/java/Duke.java | 36 ++++++++++++++++++------------------
 1 file changed, 18 insertions(+), 18 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index c3b47fa2f..987bf8aa3 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -17,7 +17,7 @@ public class Duke {
 
     final private static String pythonEmoji = "\uD83D\uDC0D";
 
-    final static private List<Task> taskList = new ArrayList<>();
+    final static private List<Task> tasks = new ArrayList<>();
     final private static Scanner in = new Scanner(System.in);
 
     private static void printHorizontalLine() {
@@ -43,55 +43,55 @@ public static void main(String[] args) {
                 System.out.printf("\t%s: Bye. See you again when you run the program again!\n", pythonEmoji);
                 break;
             case "list":
-                System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, taskList.size());
-                for(int taskNo = 1; taskNo <= taskList.size(); taskNo++) {
+                System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, tasks.size());
+                for(int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
                     System.out.printf("\t\t\t%d. [%s] %s\n",
-                            taskNo, taskList.get(taskNo - 1).getStatusIcon(),
-                            taskList.get(taskNo - 1).getDescription());
+                            taskNo, tasks.get(taskNo - 1).getStatusIcon(),
+                            tasks.get(taskNo - 1).getDescription());
                 }
                 break;
             case "mark": {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
-                if (taskNo > taskList.size()) {
+                if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", pythonEmoji);
                     break;
                 }
-                if (taskList.get(taskNo - 1).isDone()) {
+                if (tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Are you from the past?\n", pythonEmoji);
                     System.out.printf("\t\tTask: \"%s\" is already done!!!\n",
-                            taskList.get(taskNo - 1).getDescription());
+                            tasks.get(taskNo - 1).getDescription());
                     break;
                 }
-                taskList.get(taskNo - 1).setDone(true);
+                tasks.get(taskNo - 1).setDone(true);
                 System.out.printf("\t%s: Good job completing the task!\n", pythonEmoji);
                 System.out.printf("\t\t\t[%s] %s\n",
-                        taskList.get(taskNo - 1).getStatusIcon(),
-                        taskList.get(taskNo - 1).getDescription());
+                        tasks.get(taskNo - 1).getStatusIcon(),
+                        tasks.get(taskNo - 1).getDescription());
                 break;
             }
             case "unmark": {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
-                if (taskNo > taskList.size()) {
+                if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", pythonEmoji);
                     break;
                 }
-                if (!taskList.get(taskNo - 1).isDone()) {
+                if (!tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", pythonEmoji);
                     System.out.printf("\t\tTask: \"%s\" is already sitting idle. Get started...!!!\n",
-                            taskList.get(taskNo - 1).getDescription());
+                            tasks.get(taskNo - 1).getDescription());
                     break;
                 }
-                taskList.get(taskNo - 1).setDone(false);
+                tasks.get(taskNo - 1).setDone(false);
                 System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", pythonEmoji);
                 System.out.printf("\t\t\t[%s] %s\n",
-                        taskList.get(taskNo - 1).getStatusIcon(),
-                        taskList.get(taskNo - 1).getDescription());
+                        tasks.get(taskNo - 1).getStatusIcon(),
+                        tasks.get(taskNo - 1).getDescription());
                 break;
             }
             default:
                 System.out.printf("\t%s: %s\n", pythonEmoji, inputLine);
                 Task task = new Task(inputLine);
-                taskList.add(task);
+                tasks.add(task);
             }
             printHorizontalLine();
         } while(!inputLine.equals("bye"));

From 7e8e63a2fd25eede0296a39021b0c6af9588b101 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 4 Sep 2023 23:39:52 +0800
Subject: [PATCH 10/59] Format and change var names to match Java standards

---
 src/main/java/Duke.java | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 987bf8aa3..b5eb9e619 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -7,14 +7,13 @@ public class Duke {
     final private static String BOT_NAME = "Python";
     final private static int HORIZONTAL_LINE_LENGTH = 80;
 
-    final private static String pythonASCIIArt =
-            "\t ____        _   _                 \n" +
-            "\t|  _ \\ _   _| |_| |__   ___  _ __  \n" +
-            "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\ \n" +
-            "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
-            "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
-            "\t       |___/                        ";
-
+    final private static String pythonAsciiArt =
+                    "\t ____        _   _                 \n" +
+                    "\t|  _ \\ _   _| |_| |__   ___  _ __  \n" +
+                    "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\ \n" +
+                    "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
+                    "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
+                    "\t       |___/                        ";
     final private static String pythonEmoji = "\uD83D\uDC0D";
 
     final static private List<Task> tasks = new ArrayList<>();
@@ -25,9 +24,9 @@ private static void printHorizontalLine() {
         Arrays.fill(horizontalLine, '—');
         System.out.println("\t" + new String(horizontalLine));
     }
-    
+
     public static void main(String[] args) {
-        System.out.println(pythonASCIIArt);
+        System.out.println(pythonAsciiArt);
         printHorizontalLine();
         System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", pythonEmoji, BOT_NAME);
         System.out.printf("\t%s: What can I do for you?\n", pythonEmoji);
@@ -44,9 +43,8 @@ public static void main(String[] args) {
                 break;
             case "list":
                 System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, tasks.size());
-                for(int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
-                    System.out.printf("\t\t\t%d. [%s] %s\n",
-                            taskNo, tasks.get(taskNo - 1).getStatusIcon(),
+                for (int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
+                    System.out.printf("\t\t\t%d. [%s] %s\n", taskNo, tasks.get(taskNo - 1).getStatusIcon(),
                             tasks.get(taskNo - 1).getDescription());
                 }
                 break;
@@ -64,8 +62,7 @@ public static void main(String[] args) {
                 }
                 tasks.get(taskNo - 1).setDone(true);
                 System.out.printf("\t%s: Good job completing the task!\n", pythonEmoji);
-                System.out.printf("\t\t\t[%s] %s\n",
-                        tasks.get(taskNo - 1).getStatusIcon(),
+                System.out.printf("\t\t\t[%s] %s\n", tasks.get(taskNo - 1).getStatusIcon(),
                         tasks.get(taskNo - 1).getDescription());
                 break;
             }
@@ -83,8 +80,7 @@ public static void main(String[] args) {
                 }
                 tasks.get(taskNo - 1).setDone(false);
                 System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", pythonEmoji);
-                System.out.printf("\t\t\t[%s] %s\n",
-                        tasks.get(taskNo - 1).getStatusIcon(),
+                System.out.printf("\t\t\t[%s] %s\n", tasks.get(taskNo - 1).getStatusIcon(),
                         tasks.get(taskNo - 1).getDescription());
                 break;
             }
@@ -92,8 +88,9 @@ public static void main(String[] args) {
                 System.out.printf("\t%s: %s\n", pythonEmoji, inputLine);
                 Task task = new Task(inputLine);
                 tasks.add(task);
+                break;
             }
             printHorizontalLine();
-        } while(!inputLine.equals("bye"));
+        } while (!inputLine.equals("bye"));
     }
 }

From 875d4bb566bde470f8c3ce3de91654d92b2ac073 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 7 Sep 2023 01:40:17 +0800
Subject: [PATCH 11/59] Add Todo class

---
 src/main/java/Task.java |  4 ++++
 src/main/java/Todo.java | 10 ++++++++++
 2 files changed, 14 insertions(+)
 create mode 100644 src/main/java/Todo.java

diff --git a/src/main/java/Task.java b/src/main/java/Task.java
index 479b5b894..c7c1682f3 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Task.java
@@ -11,6 +11,10 @@ public String getStatusIcon() {
         return (isDone ? "X" : " "); // mark done task with X
     }
 
+    public String getTypeIcon() {
+        return " ";
+    }
+
     public String getDescription() {
         return description;
     }
diff --git a/src/main/java/Todo.java b/src/main/java/Todo.java
new file mode 100644
index 000000000..ff5d1a5bd
--- /dev/null
+++ b/src/main/java/Todo.java
@@ -0,0 +1,10 @@
+public class Todo extends Task{
+    public Todo(String description) {
+        super(description);
+    }
+
+    @Override
+    public String getTypeIcon() {
+        return "T";
+    }
+}

From dca8d876119dbceef20b97ac1bc6611e595abe36 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 10:48:34 +0800
Subject: [PATCH 12/59] Add toString method to task class

---
 src/main/java/Duke.java | 17 +++++++----------
 src/main/java/Task.java |  9 +++++++--
 2 files changed, 14 insertions(+), 12 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index b5eb9e619..a31f28c8e 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -44,8 +44,7 @@ public static void main(String[] args) {
             case "list":
                 System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, tasks.size());
                 for (int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
-                    System.out.printf("\t\t\t%d. [%s] %s\n", taskNo, tasks.get(taskNo - 1).getStatusIcon(),
-                            tasks.get(taskNo - 1).getDescription());
+                    System.out.printf("\t\t\t%d. %s\n", taskNo, tasks.get(taskNo - 1));
                 }
                 break;
             case "mark": {
@@ -56,14 +55,13 @@ public static void main(String[] args) {
                 }
                 if (tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Are you from the past?\n", pythonEmoji);
-                    System.out.printf("\t\tTask: \"%s\" is already done!!!\n",
-                            tasks.get(taskNo - 1).getDescription());
+                    System.out.printf("\t\tTask: %s\n is already done!!!\n",
+                            tasks.get(taskNo - 1));
                     break;
                 }
                 tasks.get(taskNo - 1).setDone(true);
                 System.out.printf("\t%s: Good job completing the task!\n", pythonEmoji);
-                System.out.printf("\t\t\t[%s] %s\n", tasks.get(taskNo - 1).getStatusIcon(),
-                        tasks.get(taskNo - 1).getDescription());
+                System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
             case "unmark": {
@@ -74,14 +72,13 @@ public static void main(String[] args) {
                 }
                 if (!tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", pythonEmoji);
-                    System.out.printf("\t\tTask: \"%s\" is already sitting idle. Get started...!!!\n",
-                            tasks.get(taskNo - 1).getDescription());
+                    System.out.printf("\t\tTask: %s\n is already sitting idle. Get started...!!!\n",
+                            tasks.get(taskNo - 1));
                     break;
                 }
                 tasks.get(taskNo - 1).setDone(false);
                 System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", pythonEmoji);
-                System.out.printf("\t\t\t[%s] %s\n", tasks.get(taskNo - 1).getStatusIcon(),
-                        tasks.get(taskNo - 1).getDescription());
+                System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
             default:
diff --git a/src/main/java/Task.java b/src/main/java/Task.java
index c7c1682f3..2234b73d9 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Task.java
@@ -8,11 +8,11 @@ public Task(String description) {
     }
 
     public String getStatusIcon() {
-        return (isDone ? "X" : " "); // mark done task with X
+        return (isDone ? "[X]" : "[ ]"); // mark done task with X
     }
 
     public String getTypeIcon() {
-        return " ";
+        return "[ ]";
     }
 
     public String getDescription() {
@@ -26,4 +26,9 @@ public boolean isDone() {
     public void setDone(boolean done) {
         isDone = done;
     }
+
+    @Override
+    public String toString() {
+        return getTypeIcon() + getStatusIcon() + " " + description;
+    }
 }

From bbb2a7541d2a88da4acb5865ad320547f5487dff Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 10:56:18 +0800
Subject: [PATCH 13/59] Implement Todo class

---
 src/main/java/Task.java | 2 +-
 src/main/java/Todo.java | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/main/java/Task.java b/src/main/java/Task.java
index 2234b73d9..88a90fe0f 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Task.java
@@ -29,6 +29,6 @@ public void setDone(boolean done) {
 
     @Override
     public String toString() {
-        return getTypeIcon() + getStatusIcon() + " " + description;
+        return getTypeIcon() + getStatusIcon() + " " + getDescription();
     }
 }
diff --git a/src/main/java/Todo.java b/src/main/java/Todo.java
index ff5d1a5bd..e0c5e6867 100644
--- a/src/main/java/Todo.java
+++ b/src/main/java/Todo.java
@@ -1,10 +1,10 @@
-public class Todo extends Task{
+public class Todo extends Task {
     public Todo(String description) {
         super(description);
     }
 
     @Override
     public String getTypeIcon() {
-        return "T";
+        return "[T]";
     }
 }

From a08b0389604916cd45eab699ef5749424504472e Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 11:00:07 +0800
Subject: [PATCH 14/59] Implement Deadline class

---
 src/main/java/Deadline.java | 13 +++++++++++++
 1 file changed, 13 insertions(+)
 create mode 100644 src/main/java/Deadline.java

diff --git a/src/main/java/Deadline.java b/src/main/java/Deadline.java
new file mode 100644
index 000000000..3328bb208
--- /dev/null
+++ b/src/main/java/Deadline.java
@@ -0,0 +1,13 @@
+public class Deadline extends Task {
+    protected String by;
+
+    public Deadline(String description, String by) {
+        super(description);
+        this.by = by;
+    }
+
+    @Override
+    public String getTypeIcon() {
+        return "[D]";
+    }
+}

From d0b678e3570754e6d3bfd1b54f1567cd367befbb Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 11:08:03 +0800
Subject: [PATCH 15/59] Implement Deadline class toString method

---
 src/main/java/Deadline.java | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/src/main/java/Deadline.java b/src/main/java/Deadline.java
index 3328bb208..5b672ed35 100644
--- a/src/main/java/Deadline.java
+++ b/src/main/java/Deadline.java
@@ -10,4 +10,13 @@ public Deadline(String description, String by) {
     public String getTypeIcon() {
         return "[D]";
     }
+
+    public String getBy() {
+        return by;
+    }
+
+    @Override
+    public String toString() {
+        return super.toString() + " (by: " + getBy() + ")";
+    }
 }

From ec7a82d573bdb8e15a59b3e1b453f4988e507ff6 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 11:08:18 +0800
Subject: [PATCH 16/59] Implement Event class

---
 src/main/java/Event.java | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)
 create mode 100644 src/main/java/Event.java

diff --git a/src/main/java/Event.java b/src/main/java/Event.java
new file mode 100644
index 000000000..d5dfbfc10
--- /dev/null
+++ b/src/main/java/Event.java
@@ -0,0 +1,26 @@
+public class Event extends Task {
+    protected String from, to;
+
+    public Event(String description, String from, String to) {
+        super(description);
+        this.from = from;
+        this.to = to;
+    }
+
+    public String getTypeIcon() {
+        return "[E]";
+    }
+
+    public String getFrom() {
+        return from;
+    }
+
+    public String getTo() {
+        return to;
+    }
+
+    @Override
+    public String toString() {
+        return super.toString() + " (from: " + getFrom() + " to: " + getTo() + ")";
+    }
+}

From 0591c0fa24d85e2556ca6f1c7c4deddf252fb9dd Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 11:42:26 +0800
Subject: [PATCH 17/59] Integrate Todo, Deadline, Event class into chatbot

---
 src/main/java/Duke.java | 43 ++++++++++++++++++++++++++++++++++-------
 1 file changed, 36 insertions(+), 7 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index a31f28c8e..c91f5da16 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -31,11 +31,10 @@ public static void main(String[] args) {
         System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", pythonEmoji, BOT_NAME);
         System.out.printf("\t%s: What can I do for you?\n", pythonEmoji);
         printHorizontalLine();
-
         String inputLine;
         do {
             inputLine = in.nextLine();
-            String inputCommand = inputLine.split(" ")[0];
+            String inputCommand = inputLine.split("\\s+")[0];
             printHorizontalLine();
             switch (inputCommand) {
             case "bye":
@@ -55,7 +54,7 @@ public static void main(String[] args) {
                 }
                 if (tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Are you from the past?\n", pythonEmoji);
-                    System.out.printf("\t\tTask: %s\n is already done!!!\n",
+                    System.out.printf("\t\tTask: %s\n \t\t is already done!!!\n",
                             tasks.get(taskNo - 1));
                     break;
                 }
@@ -72,7 +71,7 @@ public static void main(String[] args) {
                 }
                 if (!tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", pythonEmoji);
-                    System.out.printf("\t\tTask: %s\n is already sitting idle. Get started...!!!\n",
+                    System.out.printf("\t\tTask: %s\n \t\tis already sitting idle. Get started...!!!\n",
                             tasks.get(taskNo - 1));
                     break;
                 }
@@ -81,10 +80,40 @@ public static void main(String[] args) {
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
+            case "todo": {
+                System.out.printf("\t%s: %s\n", pythonEmoji, "New Todo! You have added this todo:");
+                final String todoDescription = inputLine.split(" ", 2)[1];
+                Todo todo = new Todo(todoDescription);
+                tasks.add(todo);
+                System.out.printf("\t\t\t %s\n", todo);
+                System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
+                break;
+            }
+            case "deadline": {
+                System.out.printf("\t%s: %s\n", pythonEmoji, "New Deadline! You have added this deadline:");
+                final String deadlineDetails = inputLine.split(" ", 2)[1];
+                final String deadlineDescription = deadlineDetails.split(" /by ")[0];
+                final String deadlineBy = deadlineDetails.split(" /by ")[1];
+                Deadline deadline = new Deadline(deadlineDescription, deadlineBy);
+                tasks.add(deadline);
+                System.out.printf("\t\t\t %s\n", deadline);
+                System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
+                break;
+            }
+            case "event": {
+                System.out.printf("\t%s: %s\n", pythonEmoji, "New Event! You have added this event:");
+                final String eventDetails = inputLine.split(" ", 2)[1];
+                final String eventDescription = eventDetails.split(" /from | /to ", 3)[0];
+                final String eventFrom = eventDetails.split(" /from | /to ", 3)[1];
+                final String eventTo = eventDetails.split(" /from | /to ", 3)[2];
+                Event event = new Event(eventDescription, eventFrom, eventTo);
+                tasks.add(event);
+                System.out.printf("\t\t\t %s\n", event);
+                System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
+                break;
+            }
             default:
-                System.out.printf("\t%s: %s\n", pythonEmoji, inputLine);
-                Task task = new Task(inputLine);
-                tasks.add(task);
+                System.out.printf("\t%s: %s\n", pythonEmoji, "I cannot understand the command!");
                 break;
             }
             printHorizontalLine();

From 846bfbf4dc9121420d39e7fa73e272001c06905e Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 12:43:16 +0800
Subject: [PATCH 18/59] Remove trailing spaces from Ascii art

---
 src/main/java/Duke.java | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index c91f5da16..572ed599b 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -8,12 +8,12 @@ public class Duke {
     final private static int HORIZONTAL_LINE_LENGTH = 80;
 
     final private static String pythonAsciiArt =
-                    "\t ____        _   _                 \n" +
-                    "\t|  _ \\ _   _| |_| |__   ___  _ __  \n" +
-                    "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\ \n" +
+                    "\t ____        _   _\n" +
+                    "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
+                    "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\\n" +
                     "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
                     "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
-                    "\t       |___/                        ";
+                    "\t       |___/";
     final private static String pythonEmoji = "\uD83D\uDC0D";
 
     final static private List<Task> tasks = new ArrayList<>();

From dd172031905fc98d93dd47c50679ffb77f48268b Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 12:47:08 +0800
Subject: [PATCH 19/59] Add input and expected behaviour of the bot

---
 text-ui-test/EXPECTED.TXT | 124 +++++++++++++++++++++++++++++++++++---
 text-ui-test/input.txt    |  22 +++++++
 2 files changed, 139 insertions(+), 7 deletions(-)

diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 657e74f6e..9143fa56b 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -1,7 +1,117 @@
-Hello from
- ____        _        
-|  _ \ _   _| | _____ 
-| | | | | | | |/ / _ \
-| |_| | |_| |   <  __/
-|____/ \__,_|_|\_\___|
-
+	 ____        _   _
+	|  _ \ _   _| |_| |__   ___  _ __
+	| |_) | | | | __|  _ \ / _ \|  _ \
+	|  __/| |_| | |_| | | | (_) | | | |
+	|_|    \__, |\__|_| |_|\___/|_| |_|
+	       |___/
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Hello! I am a short Java Bot Python!
+	🐍: What can I do for you?
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Todo! You have added this todo:
+			 [T][ ] borrow book
+		You have 1 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Todo! You have added this todo:
+			 [T][ ] borrow cycle
+		You have 2 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Todo! You have added this todo:
+			 [T][ ] cycle
+		You have 3 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Deadline! You have added this deadline:
+			 [D][ ] return book (by: Sunday)
+		You have 4 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Event! You have added this event:
+			 [E][ ] project meeting (from: Mon 2pm to: 4pm)
+		You have 5 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Event! You have added this event:
+			 [E][ ] group study (from: 1pm to to: 2pm)
+		You have 6 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 6 tasks to do!
+			1. [T][ ] borrow book
+			2. [T][ ] borrow cycle
+			3. [T][ ] cycle
+			4. [D][ ] return book (by: Sunday)
+			5. [E][ ] project meeting (from: Mon 2pm to: 4pm)
+			6. [E][ ] group study (from: 1pm to to: 2pm)
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Good job completing the task!
+			 [T][X] borrow book
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Are you from the past?
+		Task: [T][X] borrow book
+ 		 is already done!!!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Its okay! To err is human! Unmarked!
+			 [T][ ] borrow book
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Alas! Only the completed tasks can be unmarked!
+		Task: [T][ ] borrow book
+ 		is already sitting idle. Get started...!!!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: I cannot understand the command!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Good job completing the task!
+			 [T][X] borrow cycle
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Good job completing the task!
+			 [T][X] cycle
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Good job completing the task!
+			 [D][X] return book (by: Sunday)
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 6 tasks to do!
+			1. [T][ ] borrow book
+			2. [T][X] borrow cycle
+			3. [T][X] cycle
+			4. [D][X] return book (by: Sunday)
+			5. [E][ ] project meeting (from: Mon 2pm to: 4pm)
+			6. [E][ ] group study (from: 1pm to to: 2pm)
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Its okay! To err is human! Unmarked!
+			 [T][ ] cycle
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Its okay! To err is human! Unmarked!
+			 [D][ ] return book (by: Sunday)
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 6 tasks to do!
+			1. [T][ ] borrow book
+			2. [T][X] borrow cycle
+			3. [T][ ] cycle
+			4. [D][ ] return book (by: Sunday)
+			5. [E][ ] project meeting (from: Mon 2pm to: 4pm)
+			6. [E][ ] group study (from: 1pm to to: 2pm)
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Are you from the future?
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Are you from the future?
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Bye. See you again when you run the program again!
+	————————————————————————————————————————————————————————————————————————————————
diff --git a/text-ui-test/input.txt b/text-ui-test/input.txt
index e69de29bb..94832e9a3 100644
--- a/text-ui-test/input.txt
+++ b/text-ui-test/input.txt
@@ -0,0 +1,22 @@
+todo borrow book
+todo borrow cycle
+todo cycle
+deadline return book /by Sunday
+event project meeting /from Mon 2pm /to 4pm
+event group study /from 1pm to /to 2pm
+list
+mark 1
+mark 1
+unmark 1
+unmark 1
+undo
+mark 2
+mark 3
+mark 4
+list
+unmark 3
+unmark 4
+list
+mark 7
+unmark 7
+bye
\ No newline at end of file

From 16606ac3ebe0f29266335376118c3b9890782d72 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 12:54:31 +0800
Subject: [PATCH 20/59] Use all capitals for constant variables

---
 src/main/java/Duke.java | 34 +++++++++++++++++-----------------
 text-ui-test/runtest.sh |  0
 2 files changed, 17 insertions(+), 17 deletions(-)
 mode change 100644 => 100755 text-ui-test/runtest.sh

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 572ed599b..1ce784d50 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -7,14 +7,14 @@ public class Duke {
     final private static String BOT_NAME = "Python";
     final private static int HORIZONTAL_LINE_LENGTH = 80;
 
-    final private static String pythonAsciiArt =
+    final private static String PYTHON_ASCII_ART =
                     "\t ____        _   _\n" +
                     "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
                     "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\\n" +
                     "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
                     "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
                     "\t       |___/";
-    final private static String pythonEmoji = "\uD83D\uDC0D";
+    final private static String PYTHON_EMOJI = "\uD83D\uDC0D";
 
     final static private List<Task> tasks = new ArrayList<>();
     final private static Scanner in = new Scanner(System.in);
@@ -26,10 +26,10 @@ private static void printHorizontalLine() {
     }
 
     public static void main(String[] args) {
-        System.out.println(pythonAsciiArt);
+        System.out.println(PYTHON_ASCII_ART);
         printHorizontalLine();
-        System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", pythonEmoji, BOT_NAME);
-        System.out.printf("\t%s: What can I do for you?\n", pythonEmoji);
+        System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", PYTHON_EMOJI, BOT_NAME);
+        System.out.printf("\t%s: What can I do for you?\n", PYTHON_EMOJI);
         printHorizontalLine();
         String inputLine;
         do {
@@ -38,10 +38,10 @@ public static void main(String[] args) {
             printHorizontalLine();
             switch (inputCommand) {
             case "bye":
-                System.out.printf("\t%s: Bye. See you again when you run the program again!\n", pythonEmoji);
+                System.out.printf("\t%s: Bye. See you again when you run the program again!\n", PYTHON_EMOJI);
                 break;
             case "list":
-                System.out.printf("\t%s: You have %d tasks to do!\n", pythonEmoji, tasks.size());
+                System.out.printf("\t%s: You have %d tasks to do!\n", PYTHON_EMOJI, tasks.size());
                 for (int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
                     System.out.printf("\t\t\t%d. %s\n", taskNo, tasks.get(taskNo - 1));
                 }
@@ -49,39 +49,39 @@ public static void main(String[] args) {
             case "mark": {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
                 if (taskNo > tasks.size()) {
-                    System.out.printf("\t%s: Are you from the future?\n", pythonEmoji);
+                    System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
                 }
                 if (tasks.get(taskNo - 1).isDone()) {
-                    System.out.printf("\t%s: Are you from the past?\n", pythonEmoji);
+                    System.out.printf("\t%s: Are you from the past?\n", PYTHON_EMOJI);
                     System.out.printf("\t\tTask: %s\n \t\t is already done!!!\n",
                             tasks.get(taskNo - 1));
                     break;
                 }
                 tasks.get(taskNo - 1).setDone(true);
-                System.out.printf("\t%s: Good job completing the task!\n", pythonEmoji);
+                System.out.printf("\t%s: Good job completing the task!\n", PYTHON_EMOJI);
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
             case "unmark": {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
                 if (taskNo > tasks.size()) {
-                    System.out.printf("\t%s: Are you from the future?\n", pythonEmoji);
+                    System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
                 }
                 if (!tasks.get(taskNo - 1).isDone()) {
-                    System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", pythonEmoji);
+                    System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", PYTHON_EMOJI);
                     System.out.printf("\t\tTask: %s\n \t\tis already sitting idle. Get started...!!!\n",
                             tasks.get(taskNo - 1));
                     break;
                 }
                 tasks.get(taskNo - 1).setDone(false);
-                System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", pythonEmoji);
+                System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", PYTHON_EMOJI);
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
             case "todo": {
-                System.out.printf("\t%s: %s\n", pythonEmoji, "New Todo! You have added this todo:");
+                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Todo! You have added this todo:");
                 final String todoDescription = inputLine.split(" ", 2)[1];
                 Todo todo = new Todo(todoDescription);
                 tasks.add(todo);
@@ -90,7 +90,7 @@ public static void main(String[] args) {
                 break;
             }
             case "deadline": {
-                System.out.printf("\t%s: %s\n", pythonEmoji, "New Deadline! You have added this deadline:");
+                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Deadline! You have added this deadline:");
                 final String deadlineDetails = inputLine.split(" ", 2)[1];
                 final String deadlineDescription = deadlineDetails.split(" /by ")[0];
                 final String deadlineBy = deadlineDetails.split(" /by ")[1];
@@ -101,7 +101,7 @@ public static void main(String[] args) {
                 break;
             }
             case "event": {
-                System.out.printf("\t%s: %s\n", pythonEmoji, "New Event! You have added this event:");
+                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Event! You have added this event:");
                 final String eventDetails = inputLine.split(" ", 2)[1];
                 final String eventDescription = eventDetails.split(" /from | /to ", 3)[0];
                 final String eventFrom = eventDetails.split(" /from | /to ", 3)[1];
@@ -113,7 +113,7 @@ public static void main(String[] args) {
                 break;
             }
             default:
-                System.out.printf("\t%s: %s\n", pythonEmoji, "I cannot understand the command!");
+                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "I cannot understand the command!");
                 break;
             }
             printHorizontalLine();
diff --git a/text-ui-test/runtest.sh b/text-ui-test/runtest.sh
old mode 100644
new mode 100755

From 28473814a0061a08b47555bd106b49b2e5db04e1 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 13:00:01 +0800
Subject: [PATCH 21/59] Change method name to getDone

---
 src/main/java/Duke.java | 4 ++--
 src/main/java/Task.java | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 1ce784d50..101918170 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -52,7 +52,7 @@ public static void main(String[] args) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
                 }
-                if (tasks.get(taskNo - 1).isDone()) {
+                if (tasks.get(taskNo - 1).getDone()) {
                     System.out.printf("\t%s: Are you from the past?\n", PYTHON_EMOJI);
                     System.out.printf("\t\tTask: %s\n \t\t is already done!!!\n",
                             tasks.get(taskNo - 1));
@@ -69,7 +69,7 @@ public static void main(String[] args) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
                 }
-                if (!tasks.get(taskNo - 1).isDone()) {
+                if (!tasks.get(taskNo - 1).getDone()) {
                     System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", PYTHON_EMOJI);
                     System.out.printf("\t\tTask: %s\n \t\tis already sitting idle. Get started...!!!\n",
                             tasks.get(taskNo - 1));
diff --git a/src/main/java/Task.java b/src/main/java/Task.java
index 88a90fe0f..7ea2ef85a 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Task.java
@@ -19,7 +19,7 @@ public String getDescription() {
         return description;
     }
 
-    public boolean isDone() {
+    public boolean getDone() {
         return isDone;
     }
 

From 2ee7cc7eb7c709a7e8a488c20ec633dea35ae45d Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 13:10:44 +0800
Subject: [PATCH 22/59] Use constant variables for command names

---
 src/main/java/Duke.java | 23 +++++++++++++++--------
 1 file changed, 15 insertions(+), 8 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 101918170..0303f170a 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -18,6 +18,13 @@ public class Duke {
 
     final static private List<Task> tasks = new ArrayList<>();
     final private static Scanner in = new Scanner(System.in);
+    public static final String COMMAND_BYE = "bye";
+    public static final String COMMAND_LIST = "list";
+    public static final String COMMAND_MARK = "mark";
+    public static final String COMMAND_UNMARK = "unmark";
+    public static final String COMMAND_TODO = "todo";
+    public static final String COMMAND_DEADLINE = "deadline";
+    public static final String COMMAND_EVENT = "event";
 
     private static void printHorizontalLine() {
         char[] horizontalLine = new char[HORIZONTAL_LINE_LENGTH];
@@ -37,16 +44,16 @@ public static void main(String[] args) {
             String inputCommand = inputLine.split("\\s+")[0];
             printHorizontalLine();
             switch (inputCommand) {
-            case "bye":
+            case COMMAND_BYE:
                 System.out.printf("\t%s: Bye. See you again when you run the program again!\n", PYTHON_EMOJI);
                 break;
-            case "list":
+            case COMMAND_LIST:
                 System.out.printf("\t%s: You have %d tasks to do!\n", PYTHON_EMOJI, tasks.size());
                 for (int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
                     System.out.printf("\t\t\t%d. %s\n", taskNo, tasks.get(taskNo - 1));
                 }
                 break;
-            case "mark": {
+            case COMMAND_MARK: {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
                 if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
@@ -63,7 +70,7 @@ public static void main(String[] args) {
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
-            case "unmark": {
+            case COMMAND_UNMARK: {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
                 if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
@@ -80,7 +87,7 @@ public static void main(String[] args) {
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
-            case "todo": {
+            case COMMAND_TODO: {
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Todo! You have added this todo:");
                 final String todoDescription = inputLine.split(" ", 2)[1];
                 Todo todo = new Todo(todoDescription);
@@ -89,7 +96,7 @@ public static void main(String[] args) {
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
                 break;
             }
-            case "deadline": {
+            case COMMAND_DEADLINE: {
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Deadline! You have added this deadline:");
                 final String deadlineDetails = inputLine.split(" ", 2)[1];
                 final String deadlineDescription = deadlineDetails.split(" /by ")[0];
@@ -100,7 +107,7 @@ public static void main(String[] args) {
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
                 break;
             }
-            case "event": {
+            case COMMAND_EVENT: {
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Event! You have added this event:");
                 final String eventDetails = inputLine.split(" ", 2)[1];
                 final String eventDescription = eventDetails.split(" /from | /to ", 3)[0];
@@ -117,6 +124,6 @@ public static void main(String[] args) {
                 break;
             }
             printHorizontalLine();
-        } while (!inputLine.equals("bye"));
+        } while (!inputLine.equals(COMMAND_BYE));
     }
 }

From edcb49980f532e785d7f4758b0bcda0206dc4742 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 13:19:03 +0800
Subject: [PATCH 23/59] Use newlines to keep coherent blocks together

---
 src/main/java/Duke.java | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 0303f170a..4bfcb76b0 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -5,8 +5,6 @@
 
 public class Duke {
     final private static String BOT_NAME = "Python";
-    final private static int HORIZONTAL_LINE_LENGTH = 80;
-
     final private static String PYTHON_ASCII_ART =
                     "\t ____        _   _\n" +
                     "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
@@ -17,7 +15,9 @@ public class Duke {
     final private static String PYTHON_EMOJI = "\uD83D\uDC0D";
 
     final static private List<Task> tasks = new ArrayList<>();
+
     final private static Scanner in = new Scanner(System.in);
+
     public static final String COMMAND_BYE = "bye";
     public static final String COMMAND_LIST = "list";
     public static final String COMMAND_MARK = "mark";
@@ -26,6 +26,7 @@ public class Duke {
     public static final String COMMAND_DEADLINE = "deadline";
     public static final String COMMAND_EVENT = "event";
 
+    final private static int HORIZONTAL_LINE_LENGTH = 80;
     private static void printHorizontalLine() {
         char[] horizontalLine = new char[HORIZONTAL_LINE_LENGTH];
         Arrays.fill(horizontalLine, '—');
@@ -38,11 +39,13 @@ public static void main(String[] args) {
         System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", PYTHON_EMOJI, BOT_NAME);
         System.out.printf("\t%s: What can I do for you?\n", PYTHON_EMOJI);
         printHorizontalLine();
+
         String inputLine;
         do {
             inputLine = in.nextLine();
             String inputCommand = inputLine.split("\\s+")[0];
             printHorizontalLine();
+
             switch (inputCommand) {
             case COMMAND_BYE:
                 System.out.printf("\t%s: Bye. See you again when you run the program again!\n", PYTHON_EMOJI);
@@ -55,6 +58,7 @@ public static void main(String[] args) {
                 break;
             case COMMAND_MARK: {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+
                 if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
@@ -65,13 +69,16 @@ public static void main(String[] args) {
                             tasks.get(taskNo - 1));
                     break;
                 }
+
                 tasks.get(taskNo - 1).setDone(true);
+
                 System.out.printf("\t%s: Good job completing the task!\n", PYTHON_EMOJI);
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
             case COMMAND_UNMARK: {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+
                 if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
@@ -82,7 +89,9 @@ public static void main(String[] args) {
                             tasks.get(taskNo - 1));
                     break;
                 }
+
                 tasks.get(taskNo - 1).setDone(false);
+
                 System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", PYTHON_EMOJI);
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
@@ -90,8 +99,10 @@ public static void main(String[] args) {
             case COMMAND_TODO: {
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Todo! You have added this todo:");
                 final String todoDescription = inputLine.split(" ", 2)[1];
+
                 Todo todo = new Todo(todoDescription);
                 tasks.add(todo);
+
                 System.out.printf("\t\t\t %s\n", todo);
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
                 break;
@@ -101,8 +112,10 @@ public static void main(String[] args) {
                 final String deadlineDetails = inputLine.split(" ", 2)[1];
                 final String deadlineDescription = deadlineDetails.split(" /by ")[0];
                 final String deadlineBy = deadlineDetails.split(" /by ")[1];
+
                 Deadline deadline = new Deadline(deadlineDescription, deadlineBy);
                 tasks.add(deadline);
+
                 System.out.printf("\t\t\t %s\n", deadline);
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
                 break;
@@ -113,8 +126,10 @@ public static void main(String[] args) {
                 final String eventDescription = eventDetails.split(" /from | /to ", 3)[0];
                 final String eventFrom = eventDetails.split(" /from | /to ", 3)[1];
                 final String eventTo = eventDetails.split(" /from | /to ", 3)[2];
+
                 Event event = new Event(eventDescription, eventFrom, eventTo);
                 tasks.add(event);
+
                 System.out.printf("\t\t\t %s\n", event);
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
                 break;

From 8235ebc08579229c4f8d439bfd62d821ec999f78 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 13:25:33 +0800
Subject: [PATCH 24/59] Add some comments

---
 src/main/java/Duke.java | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 4bfcb76b0..db450cc3b 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -43,6 +43,8 @@ public static void main(String[] args) {
         String inputLine;
         do {
             inputLine = in.nextLine();
+
+            // Trim extra whitespace characters between words while splitting
             String inputCommand = inputLine.split("\\s+")[0];
             printHorizontalLine();
 
@@ -59,6 +61,7 @@ public static void main(String[] args) {
             case COMMAND_MARK: {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
 
+                // Handle unintended usage
                 if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
@@ -79,6 +82,7 @@ public static void main(String[] args) {
             case COMMAND_UNMARK: {
                 int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
 
+                // Handle unintended usage
                 if (taskNo > tasks.size()) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;

From 16258c40332287488392949d3ee8ae7fe7d6c3df Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 14:40:19 +0800
Subject: [PATCH 25/59] Make Task class abstract

---
 src/main/java/Task.java | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/main/java/Task.java b/src/main/java/Task.java
index 7ea2ef85a..06c84883f 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Task.java
@@ -1,4 +1,4 @@
-public class Task {
+public abstract class Task {
     protected String description;
     protected boolean isDone;
 
@@ -11,9 +11,7 @@ public String getStatusIcon() {
         return (isDone ? "[X]" : "[ ]"); // mark done task with X
     }
 
-    public String getTypeIcon() {
-        return "[ ]";
-    }
+    public abstract String getTypeIcon();
 
     public String getDescription() {
         return description;

From 54707ec1465814ae2e40d78ca2185fdb8cf89055 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 15:22:05 +0800
Subject: [PATCH 26/59] Catch exceptions and respond for unexpected input

---
 src/main/java/Duke.java | 80 +++++++++++++++++++++++++++++++++++------
 1 file changed, 70 insertions(+), 10 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index db450cc3b..65526393e 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -59,7 +59,14 @@ public static void main(String[] args) {
                 }
                 break;
             case COMMAND_MARK: {
-                int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+                int taskNo;
+                try {
+                    taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+                } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_MARK + " command must be followed by an integer (task" +
+                            " id)!");
+                    break;
+                }
 
                 // Handle unintended usage
                 if (taskNo > tasks.size()) {
@@ -80,7 +87,14 @@ public static void main(String[] args) {
                 break;
             }
             case COMMAND_UNMARK: {
-                int taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+                int taskNo;
+                try {
+                    taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+                } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_MARK + " command must be followed by an integer (task" +
+                            " id).");
+                    break;
+                }
 
                 // Handle unintended usage
                 if (taskNo > tasks.size()) {
@@ -101,8 +115,16 @@ public static void main(String[] args) {
                 break;
             }
             case COMMAND_TODO: {
+                String todoDescription;
+                try {
+                    todoDescription = inputLine.split(" ", 2)[1];
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_TODO + " command must be followed by a task " +
+                            "description");
+                    break;
+                }
+
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Todo! You have added this todo:");
-                final String todoDescription = inputLine.split(" ", 2)[1];
 
                 Todo todo = new Todo(todoDescription);
                 tasks.add(todo);
@@ -112,10 +134,24 @@ public static void main(String[] args) {
                 break;
             }
             case COMMAND_DEADLINE: {
+                String deadlineDetails, deadlineDescription, deadlineBy;
+                try {
+                    deadlineDetails = inputLine.split(" ", 2)[1];
+                    deadlineDescription = deadlineDetails.split(" /by ")[0];
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_DEADLINE + " command must be followed by a task " +
+                            "description!");
+                    break;
+                }
+                try {
+                    deadlineBy = deadlineDetails.split(" /by ")[1];
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_DEADLINE + " command must have /by clause followed by " +
+                            "time its due!");
+                    break;
+                }
+
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Deadline! You have added this deadline:");
-                final String deadlineDetails = inputLine.split(" ", 2)[1];
-                final String deadlineDescription = deadlineDetails.split(" /by ")[0];
-                final String deadlineBy = deadlineDetails.split(" /by ")[1];
 
                 Deadline deadline = new Deadline(deadlineDescription, deadlineBy);
                 tasks.add(deadline);
@@ -125,11 +161,31 @@ public static void main(String[] args) {
                 break;
             }
             case COMMAND_EVENT: {
+                String eventDetails, eventDescription, eventFrom, eventTo;
+                try {
+                    eventDetails = inputLine.split(" ", 2)[1];
+                    eventDescription = eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[0];
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_EVENT + " command must be followed by a task " +
+                            "description!");
+                    break;
+                }
+                try {
+                    eventFrom = eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[1];
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_EVENT + " command must have /from clause followed by " +
+                            "time it starts!");
+                    break;
+                }
+                try {
+                    eventTo = eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[2];
+                } catch (ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_EVENT + " command must have /to clause followed by " +
+                            "time it ends!");
+                    break;
+                }
+
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Event! You have added this event:");
-                final String eventDetails = inputLine.split(" ", 2)[1];
-                final String eventDescription = eventDetails.split(" /from | /to ", 3)[0];
-                final String eventFrom = eventDetails.split(" /from | /to ", 3)[1];
-                final String eventTo = eventDetails.split(" /from | /to ", 3)[2];
 
                 Event event = new Event(eventDescription, eventFrom, eventTo);
                 tasks.add(event);
@@ -139,6 +195,10 @@ public static void main(String[] args) {
                 break;
             }
             default:
+                if (inputLine.isEmpty()) {
+                    System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "Nothing for me?");
+                    break;
+                }
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "I cannot understand the command!");
                 break;
             }

From c60023af08ecd867aeea12d8cca8765e062ebe98 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 15:28:34 +0800
Subject: [PATCH 27/59] Fix typo in Duke

---
 src/main/java/Duke.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/java/Duke.java b/src/main/java/Duke.java
index 65526393e..36b71aa87 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Duke.java
@@ -91,7 +91,7 @@ public static void main(String[] args) {
                 try {
                     taskNo = Integer.parseInt(inputLine.split(" ")[1]);
                 } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_MARK + " command must be followed by an integer (task" +
+                    System.out.println("\t" + COMMAND_UNMARK + " command must be followed by an integer (task" +
                             " id).");
                     break;
                 }
@@ -120,7 +120,7 @@ public static void main(String[] args) {
                     todoDescription = inputLine.split(" ", 2)[1];
                 } catch (ArrayIndexOutOfBoundsException e) {
                     System.out.println("\t" + COMMAND_TODO + " command must be followed by a task " +
-                            "description");
+                            "description!");
                     break;
                 }
 

From 652ef28ae0d7dce05a04dff7cb254bd582ae7771 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 14 Sep 2023 15:29:01 +0800
Subject: [PATCH 28/59] Update input.txt and EXPECTED.TXT

---
 text-ui-test/EXPECTED.TXT | 63 ++++++++++++++++++++++++++++++++++++---
 text-ui-test/input.txt    | 15 ++++++++++
 2 files changed, 74 insertions(+), 4 deletions(-)

diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 9143fa56b..232a8745b 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -48,6 +48,9 @@
 			6. [E][ ] group study (from: 1pm to to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
+	🐍: Nothing for me?
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
 			 [T][X] borrow book
 	————————————————————————————————————————————————————————————————————————————————
@@ -69,6 +72,18 @@
 	🐍: I cannot understand the command!
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
+	mark command must be followed by an integer (task id)!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	mark command must be followed by an integer (task id)!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	unmark command must be followed by an integer (task id).
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	unmark command must be followed by an integer (task id).
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
 			 [T][X] borrow cycle
 	————————————————————————————————————————————————————————————————————————————————
@@ -81,13 +96,49 @@
 			 [D][X] return book (by: Sunday)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: You have 6 tasks to do!
+	todo command must be followed by a task description!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	deadline command must be followed by a task description!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	event command must be followed by a task description!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	deadline command must have /by clause followed by time its due!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	deadline command must have /by clause followed by time its due!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Deadline! You have added this deadline:
+			 [D][ ] return book (by: 2 June)
+		You have 7 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	event command must have /from clause followed by time it starts!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	event command must have /to clause followed by time it ends!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	event command must have /to clause followed by time it ends!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: New Event! You have added this event:
+			 [E][ ] OOP Lecture (from: 12pm to: 2pm)
+		You have 8 tasks in total!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 8 tasks to do!
 			1. [T][ ] borrow book
 			2. [T][X] borrow cycle
 			3. [T][X] cycle
 			4. [D][X] return book (by: Sunday)
 			5. [E][ ] project meeting (from: Mon 2pm to: 4pm)
 			6. [E][ ] group study (from: 1pm to to: 2pm)
+			7. [D][ ] return book (by: 2 June)
+			8. [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Its okay! To err is human! Unmarked!
@@ -98,19 +149,23 @@
 			 [D][ ] return book (by: Sunday)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: You have 6 tasks to do!
+	🐍: You have 8 tasks to do!
 			1. [T][ ] borrow book
 			2. [T][X] borrow cycle
 			3. [T][ ] cycle
 			4. [D][ ] return book (by: Sunday)
 			5. [E][ ] project meeting (from: Mon 2pm to: 4pm)
 			6. [E][ ] group study (from: 1pm to to: 2pm)
+			7. [D][ ] return book (by: 2 June)
+			8. [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: Are you from the future?
+	🐍: Good job completing the task!
+			 [D][X] return book (by: 2 June)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: Are you from the future?
+	🐍: Its okay! To err is human! Unmarked!
+			 [D][ ] return book (by: 2 June)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Bye. See you again when you run the program again!
diff --git a/text-ui-test/input.txt b/text-ui-test/input.txt
index 94832e9a3..246df2ce6 100644
--- a/text-ui-test/input.txt
+++ b/text-ui-test/input.txt
@@ -5,14 +5,29 @@ deadline return book /by Sunday
 event project meeting /from Mon 2pm /to 4pm
 event group study /from 1pm to /to 2pm
 list
+
 mark 1
 mark 1
 unmark 1
 unmark 1
 undo
+mark a
+mark
+unmark c
+unmark
 mark 2
 mark 3
 mark 4
+todo
+deadline
+event
+deadline return book
+deadline return book /by
+deadline return book /by 2 June
+event OOP Lecture
+event OOP Lecture /from 12pm
+event OOP Lecture /from /to 2pm
+event OOP Lecture /from 12pm /to 2pm
 list
 unmark 3
 unmark 4

From a45995bd4217676c375b018fa1b7b90d2b1dc764 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 13:35:35 +0800
Subject: [PATCH 29/59] Rename Duke to Python

---
 src/main/java/{Duke.java => Python.java} | 2 +-
 text-ui-test/runtest.sh                  | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)
 rename src/main/java/{Duke.java => Python.java} (99%)

diff --git a/src/main/java/Duke.java b/src/main/java/Python.java
similarity index 99%
rename from src/main/java/Duke.java
rename to src/main/java/Python.java
index 36b71aa87..090d36a36 100644
--- a/src/main/java/Duke.java
+++ b/src/main/java/Python.java
@@ -3,7 +3,7 @@
 import java.util.List;
 import java.util.Scanner;
 
-public class Duke {
+public class Python {
     final private static String BOT_NAME = "Python";
     final private static String PYTHON_ASCII_ART =
                     "\t ____        _   _\n" +
diff --git a/text-ui-test/runtest.sh b/text-ui-test/runtest.sh
index c9ec87003..3f7371b54 100755
--- a/text-ui-test/runtest.sh
+++ b/text-ui-test/runtest.sh
@@ -20,7 +20,7 @@ then
 fi
 
 # run the program, feed commands from input.txt file and redirect the output to the ACTUAL.TXT
-java -classpath ../bin Duke < input.txt > ACTUAL.TXT
+java -classpath ../bin Python < input.txt > ACTUAL.TXT
 
 # convert to UNIX format
 cp EXPECTED.TXT EXPECTED-UNIX.TXT

From a35adecfd3d81891faefa00a4a909c9e0c11feb7 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 13:41:39 +0800
Subject: [PATCH 30/59] Organize files into packages

---
 src/main/java/{ => Python}/Python.java        | 7 +++++++
 src/main/java/{ => Python/Task}/Deadline.java | 2 ++
 src/main/java/{ => Python/Task}/Event.java    | 2 ++
 src/main/java/{ => Python/Task}/Task.java     | 2 ++
 src/main/java/{ => Python/Task}/Todo.java     | 2 ++
 5 files changed, 15 insertions(+)
 rename src/main/java/{ => Python}/Python.java (98%)
 rename src/main/java/{ => Python/Task}/Deadline.java (94%)
 rename src/main/java/{ => Python/Task}/Event.java (95%)
 rename src/main/java/{ => Python/Task}/Task.java (96%)
 rename src/main/java/{ => Python/Task}/Todo.java (89%)

diff --git a/src/main/java/Python.java b/src/main/java/Python/Python.java
similarity index 98%
rename from src/main/java/Python.java
rename to src/main/java/Python/Python.java
index 090d36a36..00c6b712f 100644
--- a/src/main/java/Python.java
+++ b/src/main/java/Python/Python.java
@@ -1,3 +1,10 @@
+package Python;
+
+import Python.Task.Deadline;
+import Python.Task.Event;
+import Python.Task.Task;
+import Python.Task.Todo;
+
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
diff --git a/src/main/java/Deadline.java b/src/main/java/Python/Task/Deadline.java
similarity index 94%
rename from src/main/java/Deadline.java
rename to src/main/java/Python/Task/Deadline.java
index 5b672ed35..40d1012e0 100644
--- a/src/main/java/Deadline.java
+++ b/src/main/java/Python/Task/Deadline.java
@@ -1,3 +1,5 @@
+package Python.Task;
+
 public class Deadline extends Task {
     protected String by;
 
diff --git a/src/main/java/Event.java b/src/main/java/Python/Task/Event.java
similarity index 95%
rename from src/main/java/Event.java
rename to src/main/java/Python/Task/Event.java
index d5dfbfc10..0b429e5ca 100644
--- a/src/main/java/Event.java
+++ b/src/main/java/Python/Task/Event.java
@@ -1,3 +1,5 @@
+package Python.Task;
+
 public class Event extends Task {
     protected String from, to;
 
diff --git a/src/main/java/Task.java b/src/main/java/Python/Task/Task.java
similarity index 96%
rename from src/main/java/Task.java
rename to src/main/java/Python/Task/Task.java
index 06c84883f..1f301e238 100644
--- a/src/main/java/Task.java
+++ b/src/main/java/Python/Task/Task.java
@@ -1,3 +1,5 @@
+package Python.Task;
+
 public abstract class Task {
     protected String description;
     protected boolean isDone;
diff --git a/src/main/java/Todo.java b/src/main/java/Python/Task/Todo.java
similarity index 89%
rename from src/main/java/Todo.java
rename to src/main/java/Python/Task/Todo.java
index e0c5e6867..b97acad9c 100644
--- a/src/main/java/Todo.java
+++ b/src/main/java/Python/Task/Todo.java
@@ -1,3 +1,5 @@
+package Python.Task;
+
 public class Todo extends Task {
     public Todo(String description) {
         super(description);

From 6ce1ada103ccd5ebe552ccdb54de2e432c403944 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 13:42:05 +0800
Subject: [PATCH 31/59] Update the path in runtest.sh

---
 text-ui-test/runtest.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/text-ui-test/runtest.sh b/text-ui-test/runtest.sh
index 3f7371b54..0a8c6cc1f 100755
--- a/text-ui-test/runtest.sh
+++ b/text-ui-test/runtest.sh
@@ -13,7 +13,7 @@ then
 fi
 
 # compile the code into the bin folder, terminates if error occurred
-if ! javac -cp ../src/main/java -Xlint:none -d ../bin ../src/main/java/*.java
+if ! javac -cp ../src/main/java -Xlint:none -d ../bin ../src/main/java/python/*.java ../src/main/java/python/task/*.java
 then
     echo "********** BUILD FAILURE **********"
     exit 1

From 96f5be8de37a0836c52de605c16c11dcf00072d4 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 14:01:26 +0800
Subject: [PATCH 32/59] Use String.repeat instead of Arrays.fill

---
 src/main/java/Python/Python.java | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/src/main/java/Python/Python.java b/src/main/java/Python/Python.java
index 00c6b712f..6638967c4 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/Python/Python.java
@@ -35,9 +35,8 @@ public class Python {
 
     final private static int HORIZONTAL_LINE_LENGTH = 80;
     private static void printHorizontalLine() {
-        char[] horizontalLine = new char[HORIZONTAL_LINE_LENGTH];
-        Arrays.fill(horizontalLine, '—');
-        System.out.println("\t" + new String(horizontalLine));
+        String horizontalLine = "-".repeat(HORIZONTAL_LINE_LENGTH);
+        System.out.println("\t" + horizontalLine);
     }
 
     public static void main(String[] args) {

From 938cdb0c6760a69a9d391b17f822871646462271 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 14:08:29 +0800
Subject: [PATCH 33/59] Change method name from getDone() to isDone()

---
 src/main/java/Python/Python.java    | 5 ++---
 src/main/java/Python/Task/Task.java | 4 ++--
 2 files changed, 4 insertions(+), 5 deletions(-)

diff --git a/src/main/java/Python/Python.java b/src/main/java/Python/Python.java
index 6638967c4..59fdd8af2 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/Python/Python.java
@@ -6,7 +6,6 @@
 import Python.Task.Todo;
 
 import java.util.ArrayList;
-import java.util.Arrays;
 import java.util.List;
 import java.util.Scanner;
 
@@ -79,7 +78,7 @@ public static void main(String[] args) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
                 }
-                if (tasks.get(taskNo - 1).getDone()) {
+                if (tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Are you from the past?\n", PYTHON_EMOJI);
                     System.out.printf("\t\tTask: %s\n \t\t is already done!!!\n",
                             tasks.get(taskNo - 1));
@@ -107,7 +106,7 @@ public static void main(String[] args) {
                     System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
                     break;
                 }
-                if (!tasks.get(taskNo - 1).getDone()) {
+                if (!tasks.get(taskNo - 1).isDone()) {
                     System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", PYTHON_EMOJI);
                     System.out.printf("\t\tTask: %s\n \t\tis already sitting idle. Get started...!!!\n",
                             tasks.get(taskNo - 1));
diff --git a/src/main/java/Python/Task/Task.java b/src/main/java/Python/Task/Task.java
index 1f301e238..e036e8982 100644
--- a/src/main/java/Python/Task/Task.java
+++ b/src/main/java/Python/Task/Task.java
@@ -10,7 +10,7 @@ public Task(String description) {
     }
 
     public String getStatusIcon() {
-        return (isDone ? "[X]" : "[ ]"); // mark done task with X
+        return (isDone() ? "[X]" : "[ ]"); // mark done task with X
     }
 
     public abstract String getTypeIcon();
@@ -19,7 +19,7 @@ public String getDescription() {
         return description;
     }
 
-    public boolean getDone() {
+    public boolean isDone() {
         return isDone;
     }
 

From 085f7ec9010bb7dc39db6e1ec3446e2b9d6faa9f Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 14:15:14 +0800
Subject: [PATCH 34/59] Use Em Dash for horizontal line

---
 src/main/java/Python/Python.java | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/main/java/Python/Python.java b/src/main/java/Python/Python.java
index 59fdd8af2..8440af64e 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/Python/Python.java
@@ -34,7 +34,7 @@ public class Python {
 
     final private static int HORIZONTAL_LINE_LENGTH = 80;
     private static void printHorizontalLine() {
-        String horizontalLine = "-".repeat(HORIZONTAL_LINE_LENGTH);
+        String horizontalLine = "—".repeat(HORIZONTAL_LINE_LENGTH);
         System.out.println("\t" + horizontalLine);
     }
 

From cabb00de92a3cad6497356babcacb7c10de73e8a Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 14:15:58 +0800
Subject: [PATCH 35/59] Fix path in runtest.sh

---
 text-ui-test/runtest.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/text-ui-test/runtest.sh b/text-ui-test/runtest.sh
index 0a8c6cc1f..338b41235 100755
--- a/text-ui-test/runtest.sh
+++ b/text-ui-test/runtest.sh
@@ -20,7 +20,7 @@ then
 fi
 
 # run the program, feed commands from input.txt file and redirect the output to the ACTUAL.TXT
-java -classpath ../bin Python < input.txt > ACTUAL.TXT
+java -classpath ../bin Python.Python < input.txt > ACTUAL.TXT
 
 # convert to UNIX format
 cp EXPECTED.TXT EXPECTED-UNIX.TXT

From 8dd6c036ca9e1140d10bca6443071f3f0f8ea6e7 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 21:34:59 +0800
Subject: [PATCH 36/59] Add support for deleting tasks

---
 src/main/java/Python/Python.java | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/main/java/Python/Python.java b/src/main/java/Python/Python.java
index 8440af64e..e840ddc5c 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/Python/Python.java
@@ -28,6 +28,7 @@ public class Python {
     public static final String COMMAND_LIST = "list";
     public static final String COMMAND_MARK = "mark";
     public static final String COMMAND_UNMARK = "unmark";
+    public static final String COMMAND_DELETE = "delete";
     public static final String COMMAND_TODO = "todo";
     public static final String COMMAND_DEADLINE = "deadline";
     public static final String COMMAND_EVENT = "event";
@@ -119,6 +120,29 @@ public static void main(String[] args) {
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 break;
             }
+            case COMMAND_DELETE: {
+                int taskNo;
+                try {
+                    taskNo = Integer.parseInt(inputLine.split(" ")[1]);
+                } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
+                    System.out.println("\t" + COMMAND_DELETE + " command must be followed by an integer (task" +
+                            " id).");
+                    break;
+                }
+
+                // Handle unintended usage
+                if (taskNo > tasks.size()) {
+                    System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
+                    System.out.printf("\t%s: You have %d tasks only!\n", PYTHON_EMOJI, tasks.size());
+                    break;
+                }
+
+                System.out.printf("\t%s: Okay. Deleting this task...!\n", PYTHON_EMOJI);
+                System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
+                tasks.remove(taskNo - 1);
+                System.out.printf("\t%s: Now, you have %d tasks!\n", PYTHON_EMOJI, tasks.size());
+                break;
+            }
             case COMMAND_TODO: {
                 String todoDescription;
                 try {

From 0960bfb14db92f8236dbe61203faedda066d8c22 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 21:37:02 +0800
Subject: [PATCH 37/59] Add tests for delete feature

---
 text-ui-test/EXPECTED.TXT | 23 +++++++++++++++++++++--
 text-ui-test/input.txt    |  3 +++
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 232a8745b..1f9dbbb37 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -160,12 +160,31 @@
 			8. [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [T][X] borrow cycle
+	🐍: Now, you have 7 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Are you from the future?
+	🐍: You have 7 tasks only!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 7 tasks to do!
+			1. [T][ ] borrow book
+			2. [T][ ] cycle
+			3. [D][ ] return book (by: Sunday)
+			4. [E][ ] project meeting (from: Mon 2pm to: 4pm)
+			5. [E][ ] group study (from: 1pm to to: 2pm)
+			6. [D][ ] return book (by: 2 June)
+			7. [E][ ] OOP Lecture (from: 12pm to: 2pm)
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
-			 [D][X] return book (by: 2 June)
+			 [E][X] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Its okay! To err is human! Unmarked!
-			 [D][ ] return book (by: 2 June)
+			 [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Bye. See you again when you run the program again!
diff --git a/text-ui-test/input.txt b/text-ui-test/input.txt
index 246df2ce6..4e117df32 100644
--- a/text-ui-test/input.txt
+++ b/text-ui-test/input.txt
@@ -32,6 +32,9 @@ list
 unmark 3
 unmark 4
 list
+delete 2
+delete 10
+list
 mark 7
 unmark 7
 bye
\ No newline at end of file

From 1d7a30b1430b05b62b9b14aa80f52cc856c0b0b8 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 22:48:05 +0800
Subject: [PATCH 38/59] Implement task details format method for file saving

---
 src/main/java/Python/Task/Deadline.java | 5 +++++
 src/main/java/Python/Task/Event.java    | 5 +++++
 src/main/java/Python/Task/Task.java     | 4 ++++
 3 files changed, 14 insertions(+)

diff --git a/src/main/java/Python/Task/Deadline.java b/src/main/java/Python/Task/Deadline.java
index 40d1012e0..4f6570507 100644
--- a/src/main/java/Python/Task/Deadline.java
+++ b/src/main/java/Python/Task/Deadline.java
@@ -21,4 +21,9 @@ public String getBy() {
     public String toString() {
         return super.toString() + " (by: " + getBy() + ")";
     }
+
+    @Override
+    public String toDiskSaveFormat() {
+        return super.toDiskSaveFormat() + " | " + getBy();
+    }
 }
diff --git a/src/main/java/Python/Task/Event.java b/src/main/java/Python/Task/Event.java
index 0b429e5ca..bf9ebb617 100644
--- a/src/main/java/Python/Task/Event.java
+++ b/src/main/java/Python/Task/Event.java
@@ -25,4 +25,9 @@ public String getTo() {
     public String toString() {
         return super.toString() + " (from: " + getFrom() + " to: " + getTo() + ")";
     }
+
+    @Override
+    public String toDiskSaveFormat() {
+        return super.toDiskSaveFormat() + " | " + getFrom() + " | " + getTo();
+    }
 }
diff --git a/src/main/java/Python/Task/Task.java b/src/main/java/Python/Task/Task.java
index e036e8982..70ff06c49 100644
--- a/src/main/java/Python/Task/Task.java
+++ b/src/main/java/Python/Task/Task.java
@@ -31,4 +31,8 @@ public void setDone(boolean done) {
     public String toString() {
         return getTypeIcon() + getStatusIcon() + " " + getDescription();
     }
+
+    public String toDiskSaveFormat() {
+        return getTypeIcon() + " | " +  getStatusIcon() + " | " + getDescription();
+    }
 }

From 4ea6ed55af8d063871b2b289e93308c2c59424ec Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 22:49:11 +0800
Subject: [PATCH 39/59] Save tasks after each change to task lists

---
 src/main/java/Python/Python.java | 55 ++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/src/main/java/Python/Python.java b/src/main/java/Python/Python.java
index 8440af64e..7b9d93cb7 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/Python/Python.java
@@ -8,6 +8,9 @@
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Scanner;
+import java.io.File;
+import java.io.IOException;
+import java.io.FileWriter;
 
 public class Python {
     final private static String BOT_NAME = "Python";
@@ -32,12 +35,59 @@ public class Python {
     public static final String COMMAND_DEADLINE = "deadline";
     public static final String COMMAND_EVENT = "event";
 
+    public static final String FILENAME_TASKS_LIST = "python.txt";
+    public static final String DIR_TASKS_LIST = "./data/";
+
     final private static int HORIZONTAL_LINE_LENGTH = 80;
     private static void printHorizontalLine() {
         String horizontalLine = "—".repeat(HORIZONTAL_LINE_LENGTH);
         System.out.println("\t" + horizontalLine);
     }
 
+    private static void writeToFile(File file, String textToAdd) throws IOException {
+        FileWriter fw = new FileWriter(file);
+        fw.write(textToAdd);
+        fw.close();
+    }
+
+    private static void saveTasksToDisk() {
+        File directory = new File(DIR_TASKS_LIST);
+        File file = new File(directory, FILENAME_TASKS_LIST);
+
+        // Check if directory exists, if not, create it
+        if (!directory.exists()) {
+            if (!directory.mkdirs()) {
+                System.out.printf("\t%s: Unable to save the tasks.\n", PYTHON_EMOJI);
+                System.out.printf("\t%s: Failed to create the directory: %s.\n", PYTHON_EMOJI,
+                        DIR_TASKS_LIST);
+                return;
+            }
+        }
+
+        try {
+            if (file.createNewFile()) {
+                System.out.printf("\t%s: Created file to store tasks: %s.\n", PYTHON_EMOJI,
+                        DIR_TASKS_LIST + FILENAME_TASKS_LIST);
+            }
+        } catch (IOException e) {
+            e.printStackTrace();
+            return;
+        }
+
+        StringBuilder contentFile = new StringBuilder();
+        for (Task task : tasks) {
+            String taskDetails = task.toDiskSaveFormat() + System.lineSeparator();
+            contentFile.append(taskDetails);
+        }
+
+        try {
+            writeToFile(file, contentFile.toString());
+        } catch (IOException e) {
+            System.out.printf("\t%s: An error occurred while writing to the file: %s.\n", PYTHON_EMOJI,
+                    e.getMessage());
+        }
+    }
+
     public static void main(String[] args) {
         System.out.println(PYTHON_ASCII_ART);
         printHorizontalLine();
@@ -89,6 +139,7 @@ public static void main(String[] args) {
 
                 System.out.printf("\t%s: Good job completing the task!\n", PYTHON_EMOJI);
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
+                saveTasksToDisk();
                 break;
             }
             case COMMAND_UNMARK: {
@@ -117,6 +168,7 @@ public static void main(String[] args) {
 
                 System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", PYTHON_EMOJI);
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
+                saveTasksToDisk();
                 break;
             }
             case COMMAND_TODO: {
@@ -136,6 +188,7 @@ public static void main(String[] args) {
 
                 System.out.printf("\t\t\t %s\n", todo);
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
+                saveTasksToDisk();
                 break;
             }
             case COMMAND_DEADLINE: {
@@ -163,6 +216,7 @@ public static void main(String[] args) {
 
                 System.out.printf("\t\t\t %s\n", deadline);
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
+                saveTasksToDisk();
                 break;
             }
             case COMMAND_EVENT: {
@@ -197,6 +251,7 @@ public static void main(String[] args) {
 
                 System.out.printf("\t\t\t %s\n", event);
                 System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
+                saveTasksToDisk();
                 break;
             }
             default:

From 3c1dc3c79145142795b462eefad088ea92fca930 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 23:55:37 +0800
Subject: [PATCH 40/59] Use type icon constant variable

---
 src/main/java/Python/Task/Deadline.java | 4 +++-
 src/main/java/Python/Task/Event.java    | 3 ++-
 src/main/java/Python/Task/Todo.java     | 5 ++++-
 3 files changed, 9 insertions(+), 3 deletions(-)

diff --git a/src/main/java/Python/Task/Deadline.java b/src/main/java/Python/Task/Deadline.java
index 4f6570507..350ce805d 100644
--- a/src/main/java/Python/Task/Deadline.java
+++ b/src/main/java/Python/Task/Deadline.java
@@ -3,6 +3,8 @@
 public class Deadline extends Task {
     protected String by;
 
+    final static public String TYPE_ICON = "[D]";
+
     public Deadline(String description, String by) {
         super(description);
         this.by = by;
@@ -10,7 +12,7 @@ public Deadline(String description, String by) {
 
     @Override
     public String getTypeIcon() {
-        return "[D]";
+        return TYPE_ICON;
     }
 
     public String getBy() {
diff --git a/src/main/java/Python/Task/Event.java b/src/main/java/Python/Task/Event.java
index bf9ebb617..179b80ada 100644
--- a/src/main/java/Python/Task/Event.java
+++ b/src/main/java/Python/Task/Event.java
@@ -2,6 +2,7 @@
 
 public class Event extends Task {
     protected String from, to;
+    final static public String TYPE_ICON = "[E]";
 
     public Event(String description, String from, String to) {
         super(description);
@@ -10,7 +11,7 @@ public Event(String description, String from, String to) {
     }
 
     public String getTypeIcon() {
-        return "[E]";
+        return TYPE_ICON;
     }
 
     public String getFrom() {
diff --git a/src/main/java/Python/Task/Todo.java b/src/main/java/Python/Task/Todo.java
index b97acad9c..8cb2a55d8 100644
--- a/src/main/java/Python/Task/Todo.java
+++ b/src/main/java/Python/Task/Todo.java
@@ -1,12 +1,15 @@
 package Python.Task;
 
 public class Todo extends Task {
+
+    final static public String TYPE_ICON = "[T]";
+
     public Todo(String description) {
         super(description);
     }
 
     @Override
     public String getTypeIcon() {
-        return "[T]";
+        return TYPE_ICON;
     }
 }

From 9141ff68884d98190e91938942d5e185fed35f84 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Mon, 18 Sep 2023 23:56:49 +0800
Subject: [PATCH 41/59] Add support for loading tasks from file

---
 src/main/java/Python/Python.java | 51 +++++++++++++++++++++++++++++++-
 1 file changed, 50 insertions(+), 1 deletion(-)

diff --git a/src/main/java/Python/Python.java b/src/main/java/Python/Python.java
index 7b9d93cb7..431ba01e5 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/Python/Python.java
@@ -10,6 +10,7 @@
 import java.util.Scanner;
 import java.io.File;
 import java.io.IOException;
+import java.io.FileNotFoundException;
 import java.io.FileWriter;
 
 public class Python {
@@ -88,10 +89,58 @@ private static void saveTasksToDisk() {
         }
     }
 
+    private static void loadTasksFromDisk() {
+        File directory = new File(DIR_TASKS_LIST);
+        File file = new File(directory, FILENAME_TASKS_LIST);
+
+        Scanner s;
+        try {
+            s = new Scanner(file);
+        } catch (FileNotFoundException e) {
+            return;
+        }
+
+        while (s.hasNext()) {
+            String[] taskDetails = s.nextLine().split(" \\| ");
+            String typeIcon = taskDetails[0];
+            if (typeIcon.equals(Todo.TYPE_ICON)) {
+                String description = taskDetails[2];
+                String isDone = taskDetails[1];
+                Todo todo = new Todo(description);
+                if (isDone.equals("[X]")) {
+                    todo.setDone(true);
+                }
+                tasks.add(todo);
+            } else if (typeIcon.equals(Deadline.TYPE_ICON)) {
+                String description = taskDetails[2];
+                String isDone = taskDetails[1];
+                String by = taskDetails[3];
+                Deadline deadline = new Deadline(description, by);
+                if (isDone.equals("[X]")) {
+                    deadline.setDone(true);
+                }
+                tasks.add(deadline);
+            } else {
+                String description = taskDetails[2];
+                String isDone = taskDetails[1];
+                String from = taskDetails[3];
+                String to = taskDetails[4];
+                Event event = new Event(description, from, to);
+                if (isDone.equals("[X]")) {
+                    event.setDone(true);
+                }
+                tasks.add(event);
+            }
+        }
+    }
+
+
     public static void main(String[] args) {
         System.out.println(PYTHON_ASCII_ART);
         printHorizontalLine();
         System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", PYTHON_EMOJI, BOT_NAME);
+        loadTasksFromDisk();
+        System.out.printf("\t%s: You currently have %d tasks!\n", PYTHON_EMOJI, tasks.size());
         System.out.printf("\t%s: What can I do for you?\n", PYTHON_EMOJI);
         printHorizontalLine();
 
@@ -108,7 +157,7 @@ public static void main(String[] args) {
                 System.out.printf("\t%s: Bye. See you again when you run the program again!\n", PYTHON_EMOJI);
                 break;
             case COMMAND_LIST:
-                System.out.printf("\t%s: You have %d tasks to do!\n", PYTHON_EMOJI, tasks.size());
+                System.out.printf("\t%s: You have %d tasks!\n", PYTHON_EMOJI, tasks.size());
                 for (int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
                     System.out.printf("\t\t\t%d. %s\n", taskNo, tasks.get(taskNo - 1));
                 }

From 6dbf98513bf860a01b9026e40103570938ef0b96 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Tue, 19 Sep 2023 00:07:49 +0800
Subject: [PATCH 42/59] Save tasks to file after delete command

---
 src/main/java/Python/Python.java | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/main/java/Python/Python.java b/src/main/java/Python/Python.java
index f66740c14..c71638ec2 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/Python/Python.java
@@ -242,6 +242,7 @@ public static void main(String[] args) {
                 System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
                 tasks.remove(taskNo - 1);
                 System.out.printf("\t%s: Now, you have %d tasks!\n", PYTHON_EMOJI, tasks.size());
+                saveTasksToDisk();
                 break;
             }
             case COMMAND_TODO: {

From 5d81533cda29d2222e4467157a0d0b669bbc27f6 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Tue, 19 Sep 2023 00:10:11 +0800
Subject: [PATCH 43/59] Ignore data folder

---
 .gitignore | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/.gitignore b/.gitignore
index 2873e189e..397229206 100644
--- a/.gitignore
+++ b/.gitignore
@@ -15,3 +15,6 @@ bin/
 
 /text-ui-test/ACTUAL.TXT
 text-ui-test/EXPECTED-UNIX.TXT
+
+# Data files
+/data/

From 1e4f7843eb9fb4fafed32e37ad3b2319ca773408 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 5 Oct 2023 14:32:08 +0800
Subject: [PATCH 44/59] Use lower case for directory names

---
 src/main/java/{Python => python}/Python.java    | 17 +++++++++++------
 .../{Python/Task => python/task}/Deadline.java  |  2 +-
 .../{Python/Task => python/task}/Event.java     |  2 +-
 .../java/{Python/Task => python/task}/Task.java |  2 +-
 .../java/{Python/Task => python/task}/Todo.java |  2 +-
 5 files changed, 15 insertions(+), 10 deletions(-)
 rename src/main/java/{Python => python}/Python.java (98%)
 rename src/main/java/{Python/Task => python/task}/Deadline.java (96%)
 rename src/main/java/{Python/Task => python/task}/Event.java (97%)
 rename src/main/java/{Python/Task => python/task}/Task.java (97%)
 rename src/main/java/{Python/Task => python/task}/Todo.java (91%)

diff --git a/src/main/java/Python/Python.java b/src/main/java/python/Python.java
similarity index 98%
rename from src/main/java/Python/Python.java
rename to src/main/java/python/Python.java
index c71638ec2..43c848114 100644
--- a/src/main/java/Python/Python.java
+++ b/src/main/java/python/Python.java
@@ -1,9 +1,9 @@
-package Python;
+package python;
 
-import Python.Task.Deadline;
-import Python.Task.Event;
-import Python.Task.Task;
-import Python.Task.Todo;
+import python.task.Deadline;
+import python.task.Event;
+import python.task.Task;
+import python.task.Todo;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -14,7 +14,7 @@
 import java.io.FileWriter;
 
 public class Python {
-    final private static String BOT_NAME = "Python";
+    final private static String BOT_NAME = "python";
     final private static String PYTHON_ASCII_ART =
                     "\t ____        _   _\n" +
                     "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
@@ -333,8 +333,13 @@ public static void main(String[] args) {
                     System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "Nothing for me?");
                     break;
                 }
+                int a = 2;
+                while (a != 3) {
+                    a++;
+                }
                 System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "I cannot understand the command!");
                 break;
+
             }
             printHorizontalLine();
         } while (!inputLine.equals(COMMAND_BYE));
diff --git a/src/main/java/Python/Task/Deadline.java b/src/main/java/python/task/Deadline.java
similarity index 96%
rename from src/main/java/Python/Task/Deadline.java
rename to src/main/java/python/task/Deadline.java
index 350ce805d..98c8b48b5 100644
--- a/src/main/java/Python/Task/Deadline.java
+++ b/src/main/java/python/task/Deadline.java
@@ -1,4 +1,4 @@
-package Python.Task;
+package python.task;
 
 public class Deadline extends Task {
     protected String by;
diff --git a/src/main/java/Python/Task/Event.java b/src/main/java/python/task/Event.java
similarity index 97%
rename from src/main/java/Python/Task/Event.java
rename to src/main/java/python/task/Event.java
index 179b80ada..d3648412b 100644
--- a/src/main/java/Python/Task/Event.java
+++ b/src/main/java/python/task/Event.java
@@ -1,4 +1,4 @@
-package Python.Task;
+package python.task;
 
 public class Event extends Task {
     protected String from, to;
diff --git a/src/main/java/Python/Task/Task.java b/src/main/java/python/task/Task.java
similarity index 97%
rename from src/main/java/Python/Task/Task.java
rename to src/main/java/python/task/Task.java
index 70ff06c49..eaea5daee 100644
--- a/src/main/java/Python/Task/Task.java
+++ b/src/main/java/python/task/Task.java
@@ -1,4 +1,4 @@
-package Python.Task;
+package python.task;
 
 public abstract class Task {
     protected String description;
diff --git a/src/main/java/Python/Task/Todo.java b/src/main/java/python/task/Todo.java
similarity index 91%
rename from src/main/java/Python/Task/Todo.java
rename to src/main/java/python/task/Todo.java
index 8cb2a55d8..b43e34ed4 100644
--- a/src/main/java/Python/Task/Todo.java
+++ b/src/main/java/python/task/Todo.java
@@ -1,4 +1,4 @@
-package Python.Task;
+package python.task;
 
 public class Todo extends Task {
 

From e6fb5156cbdc0d9499ba2bc800785b032cbc8863 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Thu, 5 Oct 2023 14:32:36 +0800
Subject: [PATCH 45/59] Update text-ui-test input and expected text

---
 text-ui-test/EXPECTED.TXT | 47 +++++++++++++++++++++++++++++++++++----
 text-ui-test/input.txt    |  8 +++++++
 2 files changed, 51 insertions(+), 4 deletions(-)

diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 1f9dbbb37..de45879d9 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -6,6 +6,7 @@
 	       |___/
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Hello! I am a short Java Bot Python!
+	🐍: You currently have 0 tasks!
 	🐍: What can I do for you?
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
@@ -39,7 +40,7 @@
 		You have 6 tasks in total!
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: You have 6 tasks to do!
+	🐍: You have 6 tasks!
 			1. [T][ ] borrow book
 			2. [T][ ] borrow cycle
 			3. [T][ ] cycle
@@ -130,7 +131,7 @@
 		You have 8 tasks in total!
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: You have 8 tasks to do!
+	🐍: You have 8 tasks!
 			1. [T][ ] borrow book
 			2. [T][X] borrow cycle
 			3. [T][X] cycle
@@ -149,7 +150,7 @@
 			 [D][ ] return book (by: Sunday)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: You have 8 tasks to do!
+	🐍: You have 8 tasks!
 			1. [T][ ] borrow book
 			2. [T][X] borrow cycle
 			3. [T][ ] cycle
@@ -169,7 +170,7 @@
 	🐍: You have 7 tasks only!
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: You have 7 tasks to do!
+	🐍: You have 7 tasks!
 			1. [T][ ] borrow book
 			2. [T][ ] cycle
 			3. [D][ ] return book (by: Sunday)
@@ -187,5 +188,43 @@
 			 [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [T][ ] borrow book
+	🐍: Now, you have 6 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [T][ ] cycle
+	🐍: Now, you have 5 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [D][ ] return book (by: Sunday)
+	🐍: Now, you have 4 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [E][ ] project meeting (from: Mon 2pm to: 4pm)
+	🐍: Now, you have 3 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [E][ ] group study (from: 1pm to to: 2pm)
+	🐍: Now, you have 2 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [D][ ] return book (by: 2 June)
+	🐍: Now, you have 1 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: Okay. Deleting this task...!
+			 [E][ ] OOP Lecture (from: 12pm to: 2pm)
+	🐍: Now, you have 0 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 0 tasks!
+	————————————————————————————————————————————————————————————————————————————————
+	————————————————————————————————————————————————————————————————————————————————
 	🐍: Bye. See you again when you run the program again!
 	————————————————————————————————————————————————————————————————————————————————
diff --git a/text-ui-test/input.txt b/text-ui-test/input.txt
index 4e117df32..5095ae969 100644
--- a/text-ui-test/input.txt
+++ b/text-ui-test/input.txt
@@ -37,4 +37,12 @@ delete 10
 list
 mark 7
 unmark 7
+delete 1
+delete 1
+delete 1
+delete 1
+delete 1
+delete 1
+delete 1
+list
 bye
\ No newline at end of file

From 19bf31a199fc2156d4661a2e61bdced2385630a6 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:53:21 +0800
Subject: [PATCH 46/59] Add Command class

---
 src/main/java/python/parser/Command.java | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
 create mode 100644 src/main/java/python/parser/Command.java

diff --git a/src/main/java/python/parser/Command.java b/src/main/java/python/parser/Command.java
new file mode 100644
index 000000000..4a1aefc09
--- /dev/null
+++ b/src/main/java/python/parser/Command.java
@@ -0,0 +1,16 @@
+package python.parser;
+
+public class Command {
+    public static final String COMMAND_BYE = "bye";
+    public static final String COMMAND_LIST = "list";
+    public static final String COMMAND_MARK = "mark";
+    public static final String COMMAND_UNMARK = "unmark";
+    public static final String COMMAND_DELETE = "delete";
+    public static final String COMMAND_TODO = "todo";
+    public static final String COMMAND_DEADLINE = "deadline";
+    public static final String COMMAND_EVENT = "event";
+
+    public static boolean isCommandBye(String command) {
+        return (command.equals(COMMAND_BYE));
+    }
+}

From d34035cf38900dae6687d8a28db069f3e0bb9f17 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:53:32 +0800
Subject: [PATCH 47/59] Add Message class

---
 src/main/java/python/ui/Message.java | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)
 create mode 100644 src/main/java/python/ui/Message.java

diff --git a/src/main/java/python/ui/Message.java b/src/main/java/python/ui/Message.java
new file mode 100644
index 000000000..6c48bbe41
--- /dev/null
+++ b/src/main/java/python/ui/Message.java
@@ -0,0 +1,28 @@
+package python.ui;
+
+public class Message {
+    final static String MESSAGE_INTRODUCTION = "Hello! I am a Java Bot Python!";
+    final static String MESSAGE_ASK = "What can I do for you?";
+    final static String MESSAGE_BYE = "Bye. See you again when you run the program again!";
+    final static String MESSAGE_INT_AFTER_COMMAND = "Command must be followed by an integer (task id)!";
+    final static String MESSAGE_DESC_AFTER_COMMAND = "Command must be followed by a task description!!";
+    final static String MESSAGE_TIME_AFTER_FROM_CLAUSE =
+            "Command must have /from clause followed by time it starts!";
+    final static String MESSAGE_TIME_AFTER_TO_CLAUSE =
+            "Command must have /to clause followed by time it ends!";
+    final static String MESSAGE_TIME_AFTER_BY_CLAUSE =
+            "Command must have /by clause followed by time its due!";
+    final static String MESSAGE_FUTURE_JOKE = "Are you from the future?";
+    final static String MESSAGE_PAST_JOKE = "Are you from the past?";
+    final static String MESSAGE_TASK_ALREADY_DONE = "Task is already done!";
+    final static String MESSAGE_CONGRATUALTE = "Good job completing the task!";
+    final static String MESSAGE_UNMARK_TASK_JOKE = "Alas! Only the completed tasks can be unmarked!";
+    final static String MESSAGE_TASK_IDLE = "Task is already sitting idle. Get started...!!!";
+    final static String MESSAGE_MISTAKE_CONSOLATION = "Its okay! To err is human! Unmarked!";
+    final static String MESSAGE_DELETE_CONFIRMATION = "Okay. Deleting this task...!";
+    final static String MESSAGE_EMPTY_COMMAND_JOKE = "Nothing for me?";
+    final static String MESSAGE_UNKNOWN_COMMAND = "I cannot understand the command!";
+    final static String MESSAGE_NEW_TODO = "New Todo! You have added this todo:";
+    final static String MESSAGE_NEW_DEADLINE = "New Deadline! You have added this deadline:";
+    final static String MESSAGE_NEW_EVENT = "New Event! You have added this event:";
+}

From e13479b18c1f12cc1ae10320700f5815b83598d2 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:53:57 +0800
Subject: [PATCH 48/59] Add Parser class

---
 src/main/java/python/parser/Parser.java | 47 +++++++++++++++++++++++++
 1 file changed, 47 insertions(+)
 create mode 100644 src/main/java/python/parser/Parser.java

diff --git a/src/main/java/python/parser/Parser.java b/src/main/java/python/parser/Parser.java
new file mode 100644
index 000000000..eaca6c578
--- /dev/null
+++ b/src/main/java/python/parser/Parser.java
@@ -0,0 +1,47 @@
+package python.parser;
+
+public class Parser {
+    public static String extractCommandFromInputLine(String inputLine) {
+        return inputLine.split("\\s+")[0];
+    }
+
+    public static String extractCommandDescFromInputLine(String inputLine) {
+        return inputLine.split(" ", 2)[1];
+    }
+
+    public static int extractTaskNoFromInputLine(String inputLine) {
+        return Integer.parseInt(inputLine.split(" ")[1]);
+    }
+
+    public static String extractTodoDescFromInputLine(String inputLine) {
+        return inputLine.split(" ", 2)[1];
+    }
+
+    public static String extractDeadlineDetailsFromInputLine(String inputLine) {
+        return inputLine.split(" ", 2)[1];
+    }
+
+    public static String extractDeadlineDescFromDeadlineDetails(String deadlineDetails) {
+        return deadlineDetails.split(" /by ")[0];
+    }
+
+    public static String extractDeadlineByFromDeadlineDetails(String deadlineDetails) {
+        return deadlineDetails.split(" /by ")[1];
+    }
+
+    public static String extractEventDetailsFromInputLine(String inputLine) {
+        return inputLine.split(" ", 2)[1];
+    }
+
+    public static String extractEventDescFromEventDetails(String eventDetails) {
+        return eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[0];
+    }
+
+    public static String extractEventFromFromEventDetails(String eventDetails) {
+        return eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[1];
+    }
+
+    public static String extractEventToFromEventDetails(String eventDetails) {
+        return eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[2];
+    }
+}

From e995cc5825330e5ed353d5703c308d54c752e1da Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:54:07 +0800
Subject: [PATCH 49/59] Add Exception class

---
 src/main/java/python/exception/PythonException.java | 7 +++++++
 1 file changed, 7 insertions(+)
 create mode 100644 src/main/java/python/exception/PythonException.java

diff --git a/src/main/java/python/exception/PythonException.java b/src/main/java/python/exception/PythonException.java
new file mode 100644
index 000000000..4c6d6198f
--- /dev/null
+++ b/src/main/java/python/exception/PythonException.java
@@ -0,0 +1,7 @@
+package python.exception;
+
+public class PythonException extends Exception {
+    public PythonException(String errorMessage) {
+        super(errorMessage);
+    }
+}
\ No newline at end of file

From 7bbab3b662d0feefef5e950a844d1687afa6a480 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:54:19 +0800
Subject: [PATCH 50/59] Add TaskList class

---
 src/main/java/python/task/TaskList.java | 37 +++++++++++++++++++++++++
 1 file changed, 37 insertions(+)
 create mode 100644 src/main/java/python/task/TaskList.java

diff --git a/src/main/java/python/task/TaskList.java b/src/main/java/python/task/TaskList.java
new file mode 100644
index 000000000..17b1714f2
--- /dev/null
+++ b/src/main/java/python/task/TaskList.java
@@ -0,0 +1,37 @@
+package python.task;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class TaskList {
+    final static private List<Task> tasks = new ArrayList<>();
+
+    public static Task getTask(int taskNo) {
+        return tasks.get(taskNo);
+    }
+
+    public static List<Task> getTasks() {
+        return tasks;
+    }
+
+    public static int getNumberOfTasks() {
+        return tasks.size();
+    }
+
+    public static void markTask(int taskNo) {
+        tasks.get(taskNo).setDone(true);
+    }
+
+    public static void unmarkTask(int taskNo) {
+        tasks.get(taskNo).setDone(false);
+    }
+
+    public static void deleteTask(int taskNo) {
+        tasks.remove(taskNo);
+    }
+
+    public static void addTask(Task task) {
+        tasks.add(task);
+    }
+
+}
\ No newline at end of file

From 4a3c6b723928622580971de0ff9ffadf2af76f1a Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:54:51 +0800
Subject: [PATCH 51/59] Add Ui class

---
 src/main/java/python/ui/Ui.java | 273 ++++++++++++++++++++++++++++++++
 1 file changed, 273 insertions(+)
 create mode 100644 src/main/java/python/ui/Ui.java

diff --git a/src/main/java/python/ui/Ui.java b/src/main/java/python/ui/Ui.java
new file mode 100644
index 000000000..ff0635041
--- /dev/null
+++ b/src/main/java/python/ui/Ui.java
@@ -0,0 +1,273 @@
+package python.ui;
+
+import python.exception.PythonException;
+import python.parser.Command;
+import python.parser.Parser;
+import python.task.Deadline;
+import python.task.Event;
+import python.task.TaskList;
+import python.task.Todo;
+
+import java.util.Scanner;
+
+public class Ui {
+    private static final Scanner in = new Scanner(System.in);
+    final private static String PYTHON_EMOJI = "\uD83D\uDC0D";
+    final private static int HORIZONTAL_LINE_LENGTH = 80;
+    private String inputLine;
+    private String inputCommand;
+
+    final private static String PYTHON_ASCII_ART =
+            "\t ____        _   _\n" +
+                    "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
+                    "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\\n" +
+                    "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
+                    "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
+                    "\t       |___/";
+
+    private static void printHorizontalLine() {
+        String horizontalLine = "—".repeat(HORIZONTAL_LINE_LENGTH);
+        System.out.println("\t" + horizontalLine);
+    }
+
+    private static void addEmojiAndPrint(String message) {
+        System.out.printf("\t%s: %s\n", PYTHON_EMOJI, message);
+    }
+
+    public void welcomeUser() {
+        System.out.println(PYTHON_ASCII_ART);
+        printHorizontalLine();
+        addEmojiAndPrint(Message.MESSAGE_INTRODUCTION);
+        displayTaskCount();
+        addEmojiAndPrint(Message.MESSAGE_ASK);
+        printHorizontalLine();
+    }
+
+    public void greetGoodBye() {
+        addEmojiAndPrint(Message.MESSAGE_BYE);
+    }
+
+    public void displayTaskCount() {
+        addEmojiAndPrint("You have " + TaskList.getNumberOfTasks() + " tasks!");
+    }
+
+    public void displayTasks() {
+        for (int taskNo = 0; taskNo < TaskList.getNumberOfTasks(); taskNo++) {
+            System.out.printf("\t\t\t%d. %s\n", taskNo + 1, TaskList.getTask(taskNo));
+        }
+    }
+
+    public void getUserInput() {
+        this.inputLine = in.nextLine();
+    }
+
+    public void displayException(Exception e) {
+        System.out.println("\tError: " + e.getMessage());
+    }
+
+    public void parseLine() {
+        this.inputCommand = Parser.extractCommandFromInputLine(inputLine);
+    }
+
+    private void handleByeCommand() {
+        greetGoodBye();
+    }
+
+    private void handleListCommand() {
+        displayTaskCount();
+        displayTasks();
+    }
+
+    private void handleMarkCommand() throws PythonException {
+        int taskNo;
+        try {
+            taskNo = Parser.extractTaskNoFromInputLine(inputLine) - 1;
+        } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_INT_AFTER_COMMAND);
+        }
+
+        // Handle unintended usage
+        if (taskNo >= TaskList.getNumberOfTasks()) {
+            addEmojiAndPrint(Message.MESSAGE_FUTURE_JOKE);
+            return;
+        }
+        if (TaskList.getTask(taskNo).isDone()) {
+            addEmojiAndPrint(Message.MESSAGE_PAST_JOKE);
+            addEmojiAndPrint(TaskList.getTask(taskNo).toString());
+            addEmojiAndPrint(Message.MESSAGE_TASK_ALREADY_DONE);
+            return;
+        }
+
+        TaskList.markTask(taskNo);
+        addEmojiAndPrint(Message.MESSAGE_CONGRATUALTE);
+        addEmojiAndPrint(TaskList.getTask(taskNo).toString());
+    }
+
+    private void handleUnmarkCommand() throws PythonException {
+        int taskNo;
+        try {
+            taskNo = Parser.extractTaskNoFromInputLine(inputLine) - 1;
+        } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_INT_AFTER_COMMAND);
+        }
+
+        // Handle unintended usage
+        if (taskNo >= TaskList.getNumberOfTasks()) {
+            addEmojiAndPrint(Message.MESSAGE_FUTURE_JOKE);
+            return;
+        }
+        if (!TaskList.getTask(taskNo).isDone()) {
+            addEmojiAndPrint(Message.MESSAGE_UNMARK_TASK_JOKE);
+            addEmojiAndPrint(TaskList.getTask(taskNo).toString());
+            addEmojiAndPrint(Message.MESSAGE_TASK_IDLE);
+            return;
+        }
+
+        TaskList.unmarkTask(taskNo);
+
+        addEmojiAndPrint(Message.MESSAGE_MISTAKE_CONSOLATION);
+        addEmojiAndPrint(TaskList.getTask(taskNo).toString());
+    }
+
+    private void handleDeleteCommand() throws PythonException {
+        int taskNo;
+
+        try {
+            taskNo = Parser.extractTaskNoFromInputLine(inputLine) - 1;
+        } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_INT_AFTER_COMMAND);
+        }
+
+        // Handle unintended usage
+        if (taskNo >= TaskList.getNumberOfTasks()) {
+            addEmojiAndPrint(Message.MESSAGE_FUTURE_JOKE);
+            displayTaskCount();
+            return;
+        }
+
+        addEmojiAndPrint(Message.MESSAGE_DELETE_CONFIRMATION);
+        addEmojiAndPrint(TaskList.getTask(taskNo).toString());
+        TaskList.deleteTask(taskNo);
+        displayTaskCount();
+    }
+
+
+    private void handleTodoCommand() throws PythonException {
+        String todoDescription;
+        try {
+            todoDescription = Parser.extractTodoDescFromInputLine(inputLine);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_DESC_AFTER_COMMAND);
+        }
+
+        addEmojiAndPrint(Message.MESSAGE_NEW_TODO);
+
+        Todo todo = new Todo(todoDescription);
+
+        TaskList.addTask(todo);
+
+        addEmojiAndPrint(todo.toString());
+        displayTaskCount();
+    }
+
+
+    private void handleDeadlineCommand() throws PythonException {
+        String deadlineDetails, deadlineDescription, deadlineBy;
+        try {
+            deadlineDetails = Parser.extractDeadlineDetailsFromInputLine(inputLine);
+            deadlineDescription = Parser.extractDeadlineDescFromDeadlineDetails(deadlineDetails);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_DESC_AFTER_COMMAND);
+        }
+        try {
+            deadlineBy = Parser.extractDeadlineByFromDeadlineDetails(deadlineDetails);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_TIME_AFTER_BY_CLAUSE);
+        }
+
+        addEmojiAndPrint(Message.MESSAGE_NEW_DEADLINE);
+
+        Deadline deadline = new Deadline(deadlineDescription, deadlineBy);
+        TaskList.addTask(deadline);
+
+        addEmojiAndPrint(deadline.toString());
+        displayTaskCount();
+    }
+
+    private void handleEventCommand() throws PythonException {
+        String eventDetails, eventDescription, eventFrom, eventTo;
+        try {
+            eventDetails = Parser.extractEventDetailsFromInputLine(inputLine);
+            eventDescription = Parser.extractEventDescFromEventDetails(eventDetails);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_DESC_AFTER_COMMAND);
+        }
+
+        try {
+            eventFrom = Parser.extractEventFromFromEventDetails(eventDetails);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_TIME_AFTER_FROM_CLAUSE);
+        }
+
+        try {
+            eventTo = Parser.extractEventToFromEventDetails(eventDetails);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_TIME_AFTER_TO_CLAUSE);
+        }
+
+        addEmojiAndPrint(Message.MESSAGE_NEW_EVENT);
+
+        Event event = new Event(eventDescription, eventFrom, eventTo);
+        TaskList.addTask(event);
+
+        addEmojiAndPrint(event.toString());
+        displayTaskCount();
+    }
+
+    private void handleUnknownCommand() throws PythonException {
+        if (inputLine.isEmpty()) {
+            addEmojiAndPrint(Message.MESSAGE_EMPTY_COMMAND_JOKE);
+            return;
+        }
+        addEmojiAndPrint(Message.MESSAGE_UNKNOWN_COMMAND);
+    }
+
+
+    public void executeLine() throws PythonException {
+        printHorizontalLine();
+        switch (inputCommand) {
+        case Command.COMMAND_BYE:
+            handleByeCommand();
+            break;
+        case Command.COMMAND_LIST:
+            handleListCommand();
+            break;
+        case Command.COMMAND_MARK:
+            handleMarkCommand();
+            break;
+        case Command.COMMAND_UNMARK:
+            handleUnmarkCommand();
+            break;
+        case Command.COMMAND_DELETE:
+            handleDeleteCommand();
+            break;
+        case Command.COMMAND_TODO:
+            handleTodoCommand();
+            break;
+        case Command.COMMAND_DEADLINE:
+            handleDeadlineCommand();
+            break;
+        case Command.COMMAND_EVENT:
+            handleEventCommand();
+            break;
+        default:
+            handleUnknownCommand();
+            break;
+        }
+    }
+
+    public boolean isExit() {
+        return Command.isCommandBye(inputCommand);
+    }
+
+}

From c84f7dc97a2b66e23ecc0d96de03467fbf886ca5 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:55:20 +0800
Subject: [PATCH 52/59] Refactor Python.java for more oop

---
 src/main/java/python/Python.java | 350 ++-----------------------------
 1 file changed, 12 insertions(+), 338 deletions(-)

diff --git a/src/main/java/python/Python.java b/src/main/java/python/Python.java
index 43c848114..61c19d953 100644
--- a/src/main/java/python/Python.java
+++ b/src/main/java/python/Python.java
@@ -1,347 +1,21 @@
 package python;
 
-import python.task.Deadline;
-import python.task.Event;
-import python.task.Task;
-import python.task.Todo;
-
-import java.util.ArrayList;
-import java.util.List;
-import java.util.Scanner;
-import java.io.File;
-import java.io.IOException;
-import java.io.FileNotFoundException;
-import java.io.FileWriter;
+import python.exception.PythonException;
+import python.ui.Ui;
 
 public class Python {
-    final private static String BOT_NAME = "python";
-    final private static String PYTHON_ASCII_ART =
-                    "\t ____        _   _\n" +
-                    "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
-                    "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\\n" +
-                    "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
-                    "\t|_|    \\__, |\\__|_| |_|\\___/|_| |_|\n" +
-                    "\t       |___/";
-    final private static String PYTHON_EMOJI = "\uD83D\uDC0D";
-
-    final static private List<Task> tasks = new ArrayList<>();
-
-    final private static Scanner in = new Scanner(System.in);
-
-    public static final String COMMAND_BYE = "bye";
-    public static final String COMMAND_LIST = "list";
-    public static final String COMMAND_MARK = "mark";
-    public static final String COMMAND_UNMARK = "unmark";
-    public static final String COMMAND_DELETE = "delete";
-    public static final String COMMAND_TODO = "todo";
-    public static final String COMMAND_DEADLINE = "deadline";
-    public static final String COMMAND_EVENT = "event";
-
-    public static final String FILENAME_TASKS_LIST = "python.txt";
-    public static final String DIR_TASKS_LIST = "./data/";
-
-    final private static int HORIZONTAL_LINE_LENGTH = 80;
-    private static void printHorizontalLine() {
-        String horizontalLine = "—".repeat(HORIZONTAL_LINE_LENGTH);
-        System.out.println("\t" + horizontalLine);
-    }
-
-    private static void writeToFile(File file, String textToAdd) throws IOException {
-        FileWriter fw = new FileWriter(file);
-        fw.write(textToAdd);
-        fw.close();
-    }
-
-    private static void saveTasksToDisk() {
-        File directory = new File(DIR_TASKS_LIST);
-        File file = new File(directory, FILENAME_TASKS_LIST);
-
-        // Check if directory exists, if not, create it
-        if (!directory.exists()) {
-            if (!directory.mkdirs()) {
-                System.out.printf("\t%s: Unable to save the tasks.\n", PYTHON_EMOJI);
-                System.out.printf("\t%s: Failed to create the directory: %s.\n", PYTHON_EMOJI,
-                        DIR_TASKS_LIST);
-                return;
-            }
-        }
-
-        try {
-            if (file.createNewFile()) {
-                System.out.printf("\t%s: Created file to store tasks: %s.\n", PYTHON_EMOJI,
-                        DIR_TASKS_LIST + FILENAME_TASKS_LIST);
-            }
-        } catch (IOException e) {
-            e.printStackTrace();
-            return;
-        }
-
-        StringBuilder contentFile = new StringBuilder();
-        for (Task task : tasks) {
-            String taskDetails = task.toDiskSaveFormat() + System.lineSeparator();
-            contentFile.append(taskDetails);
-        }
-
-        try {
-            writeToFile(file, contentFile.toString());
-        } catch (IOException e) {
-            System.out.printf("\t%s: An error occurred while writing to the file: %s.\n", PYTHON_EMOJI,
-                    e.getMessage());
-        }
-    }
-
-    private static void loadTasksFromDisk() {
-        File directory = new File(DIR_TASKS_LIST);
-        File file = new File(directory, FILENAME_TASKS_LIST);
-
-        Scanner s;
-        try {
-            s = new Scanner(file);
-        } catch (FileNotFoundException e) {
-            return;
-        }
-
-        while (s.hasNext()) {
-            String[] taskDetails = s.nextLine().split(" \\| ");
-            String typeIcon = taskDetails[0];
-            if (typeIcon.equals(Todo.TYPE_ICON)) {
-                String description = taskDetails[2];
-                String isDone = taskDetails[1];
-                Todo todo = new Todo(description);
-                if (isDone.equals("[X]")) {
-                    todo.setDone(true);
-                }
-                tasks.add(todo);
-            } else if (typeIcon.equals(Deadline.TYPE_ICON)) {
-                String description = taskDetails[2];
-                String isDone = taskDetails[1];
-                String by = taskDetails[3];
-                Deadline deadline = new Deadline(description, by);
-                if (isDone.equals("[X]")) {
-                    deadline.setDone(true);
-                }
-                tasks.add(deadline);
-            } else {
-                String description = taskDetails[2];
-                String isDone = taskDetails[1];
-                String from = taskDetails[3];
-                String to = taskDetails[4];
-                Event event = new Event(description, from, to);
-                if (isDone.equals("[X]")) {
-                    event.setDone(true);
-                }
-                tasks.add(event);
-            }
-        }
-    }
-
+    static final private Ui ui = new Ui();
 
     public static void main(String[] args) {
-        System.out.println(PYTHON_ASCII_ART);
-        printHorizontalLine();
-        System.out.printf("\t%s: Hello! I am a short Java Bot %s!\n", PYTHON_EMOJI, BOT_NAME);
-        loadTasksFromDisk();
-        System.out.printf("\t%s: You currently have %d tasks!\n", PYTHON_EMOJI, tasks.size());
-        System.out.printf("\t%s: What can I do for you?\n", PYTHON_EMOJI);
-        printHorizontalLine();
-
-        String inputLine;
+        ui.welcomeUser();
         do {
-            inputLine = in.nextLine();
-
-            // Trim extra whitespace characters between words while splitting
-            String inputCommand = inputLine.split("\\s+")[0];
-            printHorizontalLine();
-
-            switch (inputCommand) {
-            case COMMAND_BYE:
-                System.out.printf("\t%s: Bye. See you again when you run the program again!\n", PYTHON_EMOJI);
-                break;
-            case COMMAND_LIST:
-                System.out.printf("\t%s: You have %d tasks!\n", PYTHON_EMOJI, tasks.size());
-                for (int taskNo = 1; taskNo <= tasks.size(); taskNo++) {
-                    System.out.printf("\t\t\t%d. %s\n", taskNo, tasks.get(taskNo - 1));
-                }
-                break;
-            case COMMAND_MARK: {
-                int taskNo;
-                try {
-                    taskNo = Integer.parseInt(inputLine.split(" ")[1]);
-                } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_MARK + " command must be followed by an integer (task" +
-                            " id)!");
-                    break;
-                }
-
-                // Handle unintended usage
-                if (taskNo > tasks.size()) {
-                    System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
-                    break;
-                }
-                if (tasks.get(taskNo - 1).isDone()) {
-                    System.out.printf("\t%s: Are you from the past?\n", PYTHON_EMOJI);
-                    System.out.printf("\t\tTask: %s\n \t\t is already done!!!\n",
-                            tasks.get(taskNo - 1));
-                    break;
-                }
-
-                tasks.get(taskNo - 1).setDone(true);
-
-                System.out.printf("\t%s: Good job completing the task!\n", PYTHON_EMOJI);
-                System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
-                saveTasksToDisk();
-                break;
-            }
-            case COMMAND_UNMARK: {
-                int taskNo;
-                try {
-                    taskNo = Integer.parseInt(inputLine.split(" ")[1]);
-                } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_UNMARK + " command must be followed by an integer (task" +
-                            " id).");
-                    break;
-                }
-
-                // Handle unintended usage
-                if (taskNo > tasks.size()) {
-                    System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
-                    break;
-                }
-                if (!tasks.get(taskNo - 1).isDone()) {
-                    System.out.printf("\t%s: Alas! Only the completed tasks can be unmarked!\n", PYTHON_EMOJI);
-                    System.out.printf("\t\tTask: %s\n \t\tis already sitting idle. Get started...!!!\n",
-                            tasks.get(taskNo - 1));
-                    break;
-                }
-
-                tasks.get(taskNo - 1).setDone(false);
-
-                System.out.printf("\t%s: Its okay! To err is human! Unmarked!\n", PYTHON_EMOJI);
-                System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
-                saveTasksToDisk();
-                break;
-            }
-            case COMMAND_DELETE: {
-                int taskNo;
-                try {
-                    taskNo = Integer.parseInt(inputLine.split(" ")[1]);
-                } catch (NumberFormatException | ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_DELETE + " command must be followed by an integer (task" +
-                            " id).");
-                    break;
-                }
-
-                // Handle unintended usage
-                if (taskNo > tasks.size()) {
-                    System.out.printf("\t%s: Are you from the future?\n", PYTHON_EMOJI);
-                    System.out.printf("\t%s: You have %d tasks only!\n", PYTHON_EMOJI, tasks.size());
-                    break;
-                }
-
-                System.out.printf("\t%s: Okay. Deleting this task...!\n", PYTHON_EMOJI);
-                System.out.printf("\t\t\t %s\n", tasks.get(taskNo - 1));
-                tasks.remove(taskNo - 1);
-                System.out.printf("\t%s: Now, you have %d tasks!\n", PYTHON_EMOJI, tasks.size());
-                saveTasksToDisk();
-                break;
-            }
-            case COMMAND_TODO: {
-                String todoDescription;
-                try {
-                    todoDescription = inputLine.split(" ", 2)[1];
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_TODO + " command must be followed by a task " +
-                            "description!");
-                    break;
-                }
-
-                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Todo! You have added this todo:");
-
-                Todo todo = new Todo(todoDescription);
-                tasks.add(todo);
-
-                System.out.printf("\t\t\t %s\n", todo);
-                System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
-                saveTasksToDisk();
-                break;
-            }
-            case COMMAND_DEADLINE: {
-                String deadlineDetails, deadlineDescription, deadlineBy;
-                try {
-                    deadlineDetails = inputLine.split(" ", 2)[1];
-                    deadlineDescription = deadlineDetails.split(" /by ")[0];
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_DEADLINE + " command must be followed by a task " +
-                            "description!");
-                    break;
-                }
-                try {
-                    deadlineBy = deadlineDetails.split(" /by ")[1];
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_DEADLINE + " command must have /by clause followed by " +
-                            "time its due!");
-                    break;
-                }
-
-                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Deadline! You have added this deadline:");
-
-                Deadline deadline = new Deadline(deadlineDescription, deadlineBy);
-                tasks.add(deadline);
-
-                System.out.printf("\t\t\t %s\n", deadline);
-                System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
-                saveTasksToDisk();
-                break;
-            }
-            case COMMAND_EVENT: {
-                String eventDetails, eventDescription, eventFrom, eventTo;
-                try {
-                    eventDetails = inputLine.split(" ", 2)[1];
-                    eventDescription = eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[0];
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_EVENT + " command must be followed by a task " +
-                            "description!");
-                    break;
-                }
-                try {
-                    eventFrom = eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[1];
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_EVENT + " command must have /from clause followed by " +
-                            "time it starts!");
-                    break;
-                }
-                try {
-                    eventTo = eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[2];
-                } catch (ArrayIndexOutOfBoundsException e) {
-                    System.out.println("\t" + COMMAND_EVENT + " command must have /to clause followed by " +
-                            "time it ends!");
-                    break;
-                }
-
-                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "New Event! You have added this event:");
-
-                Event event = new Event(eventDescription, eventFrom, eventTo);
-                tasks.add(event);
-
-                System.out.printf("\t\t\t %s\n", event);
-                System.out.printf("\t\tYou have %d tasks in total!\n", tasks.size());
-                saveTasksToDisk();
-                break;
-            }
-            default:
-                if (inputLine.isEmpty()) {
-                    System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "Nothing for me?");
-                    break;
-                }
-                int a = 2;
-                while (a != 3) {
-                    a++;
-                }
-                System.out.printf("\t%s: %s\n", PYTHON_EMOJI, "I cannot understand the command!");
-                break;
-
-            }
-            printHorizontalLine();
-        } while (!inputLine.equals(COMMAND_BYE));
+            ui.getUserInput();
+            try {
+                ui.parseLine();
+                ui.executeLine();
+            } catch (PythonException e) {
+                ui.displayException(e);
+            }
+        } while(!ui.isExit());
     }
 }

From dd0cf106e7003cfcf1e62e506a2fbdf85ef63c2e Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 20:56:48 +0800
Subject: [PATCH 53/59] Update text-ui-testing

---
 text-ui-test/EXPECTED.TXT | 168 ++++++++++++++------------------------
 text-ui-test/runtest.sh   |   4 +-
 2 files changed, 62 insertions(+), 110 deletions(-)

diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index de45879d9..3631c6c30 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -5,40 +5,34 @@
 	|_|    \__, |\__|_| |_|\___/|_| |_|
 	       |___/
 	————————————————————————————————————————————————————————————————————————————————
-	🐍: Hello! I am a short Java Bot Python!
-	🐍: You currently have 0 tasks!
+	🐍: Hello! I am a Java Bot Python!
+	🐍: You have 0 tasks!
 	🐍: What can I do for you?
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Todo! You have added this todo:
-			 [T][ ] borrow book
-		You have 1 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] borrow book
+	🐍: You have 1 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Todo! You have added this todo:
-			 [T][ ] borrow cycle
-		You have 2 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] borrow cycle
+	🐍: You have 2 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Todo! You have added this todo:
-			 [T][ ] cycle
-		You have 3 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] cycle
+	🐍: You have 3 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Deadline! You have added this deadline:
-			 [D][ ] return book (by: Sunday)
-		You have 4 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [D][ ] return book (by: Sunday)
+	🐍: You have 4 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Event! You have added this event:
-			 [E][ ] project meeting (from: Mon 2pm to: 4pm)
-		You have 5 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][ ] project meeting (from: Mon 2pm to: 4pm)
+	🐍: You have 5 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Event! You have added this event:
-			 [E][ ] group study (from: 1pm to to: 2pm)
-		You have 6 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][ ] group study (from: 1pm to to: 2pm)
+	🐍: You have 6 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: You have 6 tasks!
 			1. [T][ ] borrow book
@@ -48,88 +42,64 @@
 			5. [E][ ] project meeting (from: Mon 2pm to: 4pm)
 			6. [E][ ] group study (from: 1pm to to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
 	🐍: Nothing for me?
 	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
-			 [T][X] borrow book
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][X] borrow book
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Are you from the past?
-		Task: [T][X] borrow book
- 		 is already done!!!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][X] borrow book
+	🐍: Task is already done!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Its okay! To err is human! Unmarked!
-			 [T][ ] borrow book
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] borrow book
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Alas! Only the completed tasks can be unmarked!
-		Task: [T][ ] borrow book
- 		is already sitting idle. Get started...!!!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] borrow book
+	🐍: Task is already sitting idle. Get started...!!!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: I cannot understand the command!
 	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must be followed by an integer (task id)!
 	————————————————————————————————————————————————————————————————————————————————
-	mark command must be followed by an integer (task id)!
+	Error: Command must be followed by an integer (task id)!
 	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must be followed by an integer (task id)!
 	————————————————————————————————————————————————————————————————————————————————
-	mark command must be followed by an integer (task id)!
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
-	unmark command must be followed by an integer (task id).
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
-	unmark command must be followed by an integer (task id).
-	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must be followed by an integer (task id)!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
-			 [T][X] borrow cycle
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][X] borrow cycle
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
-			 [T][X] cycle
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][X] cycle
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
-			 [D][X] return book (by: Sunday)
+	🐍: [D][X] return book (by: Sunday)
 	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must be followed by a task description!!
 	————————————————————————————————————————————————————————————————————————————————
-	todo command must be followed by a task description!
+	Error: Command must be followed by a task description!!
 	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must be followed by a task description!!
 	————————————————————————————————————————————————————————————————————————————————
-	deadline command must be followed by a task description!
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
-	event command must be followed by a task description!
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
-	deadline command must have /by clause followed by time its due!
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
-	deadline command must have /by clause followed by time its due!
+	Error: Command must have /by clause followed by time its due!
 	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must have /by clause followed by time its due!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Deadline! You have added this deadline:
-			 [D][ ] return book (by: 2 June)
-		You have 7 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
-	event command must have /from clause followed by time it starts!
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
-	event command must have /to clause followed by time it ends!
+	🐍: [D][ ] return book (by: 2 June)
+	🐍: You have 7 tasks!
 	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must have /from clause followed by time it starts!
 	————————————————————————————————————————————————————————————————————————————————
-	event command must have /to clause followed by time it ends!
+	Error: Command must have /to clause followed by time it ends!
 	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must have /to clause followed by time it ends!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: New Event! You have added this event:
-			 [E][ ] OOP Lecture (from: 12pm to: 2pm)
-		You have 8 tasks in total!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][ ] OOP Lecture (from: 12pm to: 2pm)
+	🐍: You have 8 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: You have 8 tasks!
 			1. [T][ ] borrow book
@@ -141,14 +111,11 @@
 			7. [D][ ] return book (by: 2 June)
 			8. [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
 	🐍: Its okay! To err is human! Unmarked!
-			 [T][ ] cycle
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] cycle
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Its okay! To err is human! Unmarked!
-			 [D][ ] return book (by: Sunday)
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [D][ ] return book (by: Sunday)
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: You have 8 tasks!
 			1. [T][ ] borrow book
@@ -160,15 +127,12 @@
 			7. [D][ ] return book (by: 2 June)
 			8. [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [T][X] borrow cycle
-	🐍: Now, you have 7 tasks!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][X] borrow cycle
+	🐍: You have 7 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Are you from the future?
-	🐍: You have 7 tasks only!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 7 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: You have 7 tasks!
 			1. [T][ ] borrow book
@@ -179,52 +143,40 @@
 			6. [D][ ] return book (by: 2 June)
 			7. [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
 	🐍: Good job completing the task!
-			 [E][X] OOP Lecture (from: 12pm to: 2pm)
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][X] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Its okay! To err is human! Unmarked!
-			 [E][ ] OOP Lecture (from: 12pm to: 2pm)
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [T][ ] borrow book
-	🐍: Now, you have 6 tasks!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] borrow book
+	🐍: You have 6 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [T][ ] cycle
-	🐍: Now, you have 5 tasks!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [T][ ] cycle
+	🐍: You have 5 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [D][ ] return book (by: Sunday)
-	🐍: Now, you have 4 tasks!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [D][ ] return book (by: Sunday)
+	🐍: You have 4 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [E][ ] project meeting (from: Mon 2pm to: 4pm)
-	🐍: Now, you have 3 tasks!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][ ] project meeting (from: Mon 2pm to: 4pm)
+	🐍: You have 3 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [E][ ] group study (from: 1pm to to: 2pm)
-	🐍: Now, you have 2 tasks!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][ ] group study (from: 1pm to to: 2pm)
+	🐍: You have 2 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [D][ ] return book (by: 2 June)
-	🐍: Now, you have 1 tasks!
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [D][ ] return book (by: 2 June)
+	🐍: You have 1 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Okay. Deleting this task...!
-			 [E][ ] OOP Lecture (from: 12pm to: 2pm)
-	🐍: Now, you have 0 tasks!
-	————————————————————————————————————————————————————————————————————————————————
-	————————————————————————————————————————————————————————————————————————————————
+	🐍: [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	🐍: You have 0 tasks!
 	————————————————————————————————————————————————————————————————————————————————
+	🐍: You have 0 tasks!
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Bye. See you again when you run the program again!
-	————————————————————————————————————————————————————————————————————————————————
diff --git a/text-ui-test/runtest.sh b/text-ui-test/runtest.sh
index 338b41235..632867c6a 100755
--- a/text-ui-test/runtest.sh
+++ b/text-ui-test/runtest.sh
@@ -13,14 +13,14 @@ then
 fi
 
 # compile the code into the bin folder, terminates if error occurred
-if ! javac -cp ../src/main/java -Xlint:none -d ../bin ../src/main/java/python/*.java ../src/main/java/python/task/*.java
+if ! javac -cp ../src/main/java -Xlint:none -d ../bin ../src/main/java/python/*.java ../src/main/java/python/task/*.java ../src/main/java/python/ui/*.java ../src/main/java/python/exception/*.java ../src/main/java/python/parser/*.java
 then
     echo "********** BUILD FAILURE **********"
     exit 1
 fi
 
 # run the program, feed commands from input.txt file and redirect the output to the ACTUAL.TXT
-java -classpath ../bin Python.Python < input.txt > ACTUAL.TXT
+java -classpath ../bin python.Python < input.txt > ACTUAL.TXT
 
 # convert to UNIX format
 cp EXPECTED.TXT EXPECTED-UNIX.TXT

From ae0c242c419a038858f2cfd5aee7cb5c3acf4d96 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 21:22:35 +0800
Subject: [PATCH 54/59] Add support for finding tasks

---
 src/main/java/python/parser/Command.java |  1 +
 src/main/java/python/parser/Parser.java  |  4 ++++
 src/main/java/python/task/TaskList.java  |  9 +++++++
 src/main/java/python/ui/Message.java     |  3 +++
 src/main/java/python/ui/Ui.java          | 30 ++++++++++++++++++++----
 text-ui-test/EXPECTED.TXT                |  9 +++++++
 text-ui-test/input.txt                   |  3 +++
 7 files changed, 55 insertions(+), 4 deletions(-)

diff --git a/src/main/java/python/parser/Command.java b/src/main/java/python/parser/Command.java
index 4a1aefc09..15d5042ac 100644
--- a/src/main/java/python/parser/Command.java
+++ b/src/main/java/python/parser/Command.java
@@ -9,6 +9,7 @@ public class Command {
     public static final String COMMAND_TODO = "todo";
     public static final String COMMAND_DEADLINE = "deadline";
     public static final String COMMAND_EVENT = "event";
+    public static final String COMMAND_FIND = "find";
 
     public static boolean isCommandBye(String command) {
         return (command.equals(COMMAND_BYE));
diff --git a/src/main/java/python/parser/Parser.java b/src/main/java/python/parser/Parser.java
index eaca6c578..1fa0a7711 100644
--- a/src/main/java/python/parser/Parser.java
+++ b/src/main/java/python/parser/Parser.java
@@ -13,6 +13,10 @@ public static int extractTaskNoFromInputLine(String inputLine) {
         return Integer.parseInt(inputLine.split(" ")[1]);
     }
 
+    public static String extractKeywordFromInputLine(String inputLine) {
+        return inputLine.split(" ")[1];
+    }
+
     public static String extractTodoDescFromInputLine(String inputLine) {
         return inputLine.split(" ", 2)[1];
     }
diff --git a/src/main/java/python/task/TaskList.java b/src/main/java/python/task/TaskList.java
index 17b1714f2..cf400bcde 100644
--- a/src/main/java/python/task/TaskList.java
+++ b/src/main/java/python/task/TaskList.java
@@ -34,4 +34,13 @@ public static void addTask(Task task) {
         tasks.add(task);
     }
 
+    public static List<Task> findTask(String keyword) {
+        List<Task> matchedTasks = new ArrayList<>();
+        for (int taskNo = 0; taskNo < getNumberOfTasks(); taskNo++) {
+            if (getTask(taskNo).getDescription().contains(keyword)) {
+                matchedTasks.add(getTask(taskNo));
+            }
+        }
+        return matchedTasks;
+    }
 }
\ No newline at end of file
diff --git a/src/main/java/python/ui/Message.java b/src/main/java/python/ui/Message.java
index 6c48bbe41..4fb48a0e5 100644
--- a/src/main/java/python/ui/Message.java
+++ b/src/main/java/python/ui/Message.java
@@ -5,6 +5,7 @@ public class Message {
     final static String MESSAGE_ASK = "What can I do for you?";
     final static String MESSAGE_BYE = "Bye. See you again when you run the program again!";
     final static String MESSAGE_INT_AFTER_COMMAND = "Command must be followed by an integer (task id)!";
+    final static String MESSAGE_KEYWORD_AFTER_COMMAND = "Command must be followed by a keyword!";
     final static String MESSAGE_DESC_AFTER_COMMAND = "Command must be followed by a task description!!";
     final static String MESSAGE_TIME_AFTER_FROM_CLAUSE =
             "Command must have /from clause followed by time it starts!";
@@ -25,4 +26,6 @@ public class Message {
     final static String MESSAGE_NEW_TODO = "New Todo! You have added this todo:";
     final static String MESSAGE_NEW_DEADLINE = "New Deadline! You have added this deadline:";
     final static String MESSAGE_NEW_EVENT = "New Event! You have added this event:";
+    final static String MESSAGE_NO_MATCH = "No matching tasks found!";
+    final static String MESSAGE_MATCHES_FOUND = "Here are the matching tasks:";
 }
diff --git a/src/main/java/python/ui/Ui.java b/src/main/java/python/ui/Ui.java
index ff0635041..5c2ffc619 100644
--- a/src/main/java/python/ui/Ui.java
+++ b/src/main/java/python/ui/Ui.java
@@ -7,7 +7,9 @@
 import python.task.Event;
 import python.task.TaskList;
 import python.task.Todo;
+import python.task.Task;
 
+import java.util.List;
 import java.util.Scanner;
 
 public class Ui {
@@ -51,9 +53,9 @@ public void displayTaskCount() {
         addEmojiAndPrint("You have " + TaskList.getNumberOfTasks() + " tasks!");
     }
 
-    public void displayTasks() {
-        for (int taskNo = 0; taskNo < TaskList.getNumberOfTasks(); taskNo++) {
-            System.out.printf("\t\t\t%d. %s\n", taskNo + 1, TaskList.getTask(taskNo));
+    public void displayTasks(List<Task> tasks) {
+        for (int taskNo = 0; taskNo < tasks.size(); taskNo++) {
+            System.out.printf("\t\t\t%d. %s\n", taskNo + 1, tasks.get(taskNo));
         }
     }
 
@@ -75,7 +77,7 @@ private void handleByeCommand() {
 
     private void handleListCommand() {
         displayTaskCount();
-        displayTasks();
+        displayTasks(TaskList.getTasks());
     }
 
     private void handleMarkCommand() throws PythonException {
@@ -224,6 +226,23 @@ private void handleEventCommand() throws PythonException {
         displayTaskCount();
     }
 
+    private void handleFindCommand() throws PythonException {
+        String keyword;
+        try {
+            keyword = Parser.extractKeywordFromInputLine(inputLine);
+        } catch (ArrayIndexOutOfBoundsException e) {
+            throw new PythonException(Message.MESSAGE_KEYWORD_AFTER_COMMAND);
+        }
+
+        List<Task> matchedTasks = TaskList.findTask(keyword);
+
+        if (matchedTasks.isEmpty()) addEmojiAndPrint(Message.MESSAGE_NO_MATCH);
+        else {
+            addEmojiAndPrint(Message.MESSAGE_MATCHES_FOUND);
+            displayTasks(matchedTasks);
+        }
+    }
+
     private void handleUnknownCommand() throws PythonException {
         if (inputLine.isEmpty()) {
             addEmojiAndPrint(Message.MESSAGE_EMPTY_COMMAND_JOKE);
@@ -260,6 +279,9 @@ public void executeLine() throws PythonException {
         case Command.COMMAND_EVENT:
             handleEventCommand();
             break;
+        case Command.COMMAND_FIND:
+            handleFindCommand();
+            break;
         default:
             handleUnknownCommand();
             break;
diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 3631c6c30..7df3c0b5c 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -101,6 +101,15 @@
 	🐍: [E][ ] OOP Lecture (from: 12pm to: 2pm)
 	🐍: You have 8 tasks!
 	————————————————————————————————————————————————————————————————————————————————
+	🐍: Here are the matching tasks:
+			1. [T][ ] borrow book
+			2. [D][X] return book (by: Sunday)
+			3. [D][ ] return book (by: 2 June)
+	————————————————————————————————————————————————————————————————————————————————
+	Error: Command must be followed by a keyword!
+	————————————————————————————————————————————————————————————————————————————————
+	🐍: No matching tasks found!
+	————————————————————————————————————————————————————————————————————————————————
 	🐍: You have 8 tasks!
 			1. [T][ ] borrow book
 			2. [T][X] borrow cycle
diff --git a/text-ui-test/input.txt b/text-ui-test/input.txt
index 5095ae969..bcbbb8412 100644
--- a/text-ui-test/input.txt
+++ b/text-ui-test/input.txt
@@ -28,6 +28,9 @@ event OOP Lecture
 event OOP Lecture /from 12pm
 event OOP Lecture /from /to 2pm
 event OOP Lecture /from 12pm /to 2pm
+find book
+find
+find exam
 list
 unmark 3
 unmark 4

From dd55af9b92d9af92a8dcee26aaed213988f07e55 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 21:25:24 +0800
Subject: [PATCH 55/59] Add manifest.mf

---
 src/main/java/META-INF/MANIFEST.MF | 3 +++
 1 file changed, 3 insertions(+)
 create mode 100644 src/main/java/META-INF/MANIFEST.MF

diff --git a/src/main/java/META-INF/MANIFEST.MF b/src/main/java/META-INF/MANIFEST.MF
new file mode 100644
index 000000000..b8735a8ae
--- /dev/null
+++ b/src/main/java/META-INF/MANIFEST.MF
@@ -0,0 +1,3 @@
+Manifest-Version: 1.0
+Main-Class: python.Python
+

From 1dab8c7a3ee6e755578ed77a716dc20548fdac58 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 22:30:26 +0800
Subject: [PATCH 56/59] Add JavaDoc comments

---
 src/main/java/python/Python.java         |  1 -
 src/main/java/python/parser/Command.java |  9 +++
 src/main/java/python/parser/Parser.java  | 75 ++++++++++++++++++++++++
 src/main/java/python/task/Deadline.java  | 34 ++++++++---
 src/main/java/python/task/Event.java     | 39 +++++++++---
 src/main/java/python/task/Task.java      | 46 +++++++++++++--
 src/main/java/python/task/TaskList.java  | 46 +++++++++++++++
 src/main/java/python/task/Todo.java      | 15 ++++-
 src/main/java/python/ui/Message.java     |  3 +
 src/main/java/python/ui/Ui.java          | 35 ++++++-----
 10 files changed, 266 insertions(+), 37 deletions(-)

diff --git a/src/main/java/python/Python.java b/src/main/java/python/Python.java
index 61c19d953..c7eaf8897 100644
--- a/src/main/java/python/Python.java
+++ b/src/main/java/python/Python.java
@@ -5,7 +5,6 @@
 
 public class Python {
     static final private Ui ui = new Ui();
-
     public static void main(String[] args) {
         ui.welcomeUser();
         do {
diff --git a/src/main/java/python/parser/Command.java b/src/main/java/python/parser/Command.java
index 15d5042ac..54e5d982f 100644
--- a/src/main/java/python/parser/Command.java
+++ b/src/main/java/python/parser/Command.java
@@ -1,5 +1,8 @@
 package python.parser;
 
+/**
+ * Defines the commands expected from the user
+ */
 public class Command {
     public static final String COMMAND_BYE = "bye";
     public static final String COMMAND_LIST = "list";
@@ -11,6 +14,12 @@ public class Command {
     public static final String COMMAND_EVENT = "event";
     public static final String COMMAND_FIND = "find";
 
+    /**
+     * Returns whether the given command is "bye" command or not
+     *
+     * @param command The command to check
+     * @return Returns whether the given command is "bye" command or not
+     */
     public static boolean isCommandBye(String command) {
         return (command.equals(COMMAND_BYE));
     }
diff --git a/src/main/java/python/parser/Parser.java b/src/main/java/python/parser/Parser.java
index 1fa0a7711..16b717f1f 100644
--- a/src/main/java/python/parser/Parser.java
+++ b/src/main/java/python/parser/Parser.java
@@ -1,50 +1,125 @@
 package python.parser;
 
+/**
+ * Contains utility functions for parsing of raw input given by the user. All classes here are static
+ */
 public class Parser {
+    /**
+     * Returns the first word as command
+     *
+     * @param inputLine The raw user input
+     * @return Returns the first word as command
+     */
     public static String extractCommandFromInputLine(String inputLine) {
         return inputLine.split("\\s+")[0];
     }
 
+    /**
+     * Returns the rest of the sentence excluding the first word
+     *
+     * @param inputLine The raw user input
+     * @return Returns the rest of the sentence excluding the first word
+     */
     public static String extractCommandDescFromInputLine(String inputLine) {
         return inputLine.split(" ", 2)[1];
     }
 
+    /**
+     * Returns the second word as integer
+     *
+     * @param inputLine The raw user input
+     * @return Returns the second word as integer
+     */
     public static int extractTaskNoFromInputLine(String inputLine) {
         return Integer.parseInt(inputLine.split(" ")[1]);
     }
 
+    /**
+     * Returns the second word as keyword
+     *
+     * @param inputLine The raw user input
+     * @return Returns the second word as keyword
+     */
     public static String extractKeywordFromInputLine(String inputLine) {
         return inputLine.split(" ")[1];
     }
 
+    /**
+     * Returns the rest of the sentence excluding the first word
+     *
+     * @param inputLine The raw user input
+     * @return Returns the rest of the sentence excluding the first word
+     */
     public static String extractTodoDescFromInputLine(String inputLine) {
         return inputLine.split(" ", 2)[1];
     }
 
+    /**
+     * Returns the rest of the sentence excluding the first word
+     *
+     * @param inputLine The raw user input
+     * @return Returns the rest of the sentence excluding the first word
+     */
     public static String extractDeadlineDetailsFromInputLine(String inputLine) {
         return inputLine.split(" ", 2)[1];
     }
 
+    /**
+     * Returns the text after the first word
+     *
+     * @param deadlineDetails The deadline details
+     * @return Returns the text after the first word
+     */
     public static String extractDeadlineDescFromDeadlineDetails(String deadlineDetails) {
         return deadlineDetails.split(" /by ")[0];
     }
 
+    /**
+     * Returns the text after the /by command
+     *
+     * @param deadlineDetails The deadline details
+     * @return Returns the text after the /by command
+     */
     public static String extractDeadlineByFromDeadlineDetails(String deadlineDetails) {
         return deadlineDetails.split(" /by ")[1];
     }
 
+    /**
+     * Returns the rest of the sentence excluding the first word
+     *
+     * @param inputLine The raw user input
+     * @return Returns the rest of the sentence excluding the first word
+     */
     public static String extractEventDetailsFromInputLine(String inputLine) {
         return inputLine.split(" ", 2)[1];
     }
 
+    /**
+     * Returns the sentence before /from
+     *
+     * @param eventDetails The event details
+     * @return Returns the sentence before /from
+     */
     public static String extractEventDescFromEventDetails(String eventDetails) {
         return eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[0];
     }
 
+    /**
+     * Returns the sentence after /from and before /to
+     *
+     * @param eventDetails The event details
+     * @return Returns the sentence after /from and before /to
+     */
     public static String extractEventFromFromEventDetails(String eventDetails) {
         return eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[1];
     }
 
+    /**
+     * Returns the sentence after /to
+     *
+     * @param eventDetails The event details
+     * @return Returns the sentence after /to
+     */
     public static String extractEventToFromEventDetails(String eventDetails) {
         return eventDetails.split("\\s+/from\\s+|\\s+/to\\s+", 3)[2];
     }
diff --git a/src/main/java/python/task/Deadline.java b/src/main/java/python/task/Deadline.java
index 98c8b48b5..5df1342a1 100644
--- a/src/main/java/python/task/Deadline.java
+++ b/src/main/java/python/task/Deadline.java
@@ -1,31 +1,49 @@
 package python.task;
 
+/**
+ * Represents a deadline object using due date
+ */
 public class Deadline extends Task {
-    protected String by;
-
-    final static public String TYPE_ICON = "[D]";
+    final static private String TYPE_ICON = "[D]";
+    private String by;
 
+    /**
+     * Constructs <code>Deadline</code> object
+     *
+     * @param description The description of the task
+     * @param by          The due datetime
+     */
     public Deadline(String description, String by) {
         super(description);
         this.by = by;
     }
 
+    /**
+     * Returns the type icon of deadline
+     *
+     * @return Returns the type icon of deadline
+     */
     @Override
     public String getTypeIcon() {
         return TYPE_ICON;
     }
 
+    /**
+     * Returns the due datetime of deadline
+     *
+     * @return Returns the due datetime of deadline
+     */
     public String getBy() {
         return by;
     }
 
+    /**
+     * Returns a human-readable string format
+     *
+     * @return Returns a human-readable string format
+     */
     @Override
     public String toString() {
         return super.toString() + " (by: " + getBy() + ")";
     }
-
-    @Override
-    public String toDiskSaveFormat() {
-        return super.toDiskSaveFormat() + " | " + getBy();
-    }
 }
diff --git a/src/main/java/python/task/Event.java b/src/main/java/python/task/Event.java
index d3648412b..9f13e3b31 100644
--- a/src/main/java/python/task/Event.java
+++ b/src/main/java/python/task/Event.java
@@ -1,34 +1,59 @@
 package python.task;
 
+/**
+ * Represents a event object using start and end datetime
+ */
 public class Event extends Task {
-    protected String from, to;
-    final static public String TYPE_ICON = "[E]";
+    final static private String TYPE_ICON = "[E]";
+    private String from, to;
 
+    /**
+     * Constructs <code>Event</code> object
+     *
+     * @param description The description of the task
+     * @param from        The start datetime of the task
+     * @param to          The end datetime of the task
+     */
     public Event(String description, String from, String to) {
         super(description);
         this.from = from;
         this.to = to;
     }
 
+    /**
+     * Returns the type icon of event
+     *
+     * @return Returns the type icon of event
+     */
     public String getTypeIcon() {
         return TYPE_ICON;
     }
 
+    /**
+     * Returns the start datetime of the event
+     *
+     * @return Returns the start datetime of the event
+     */
     public String getFrom() {
         return from;
     }
 
+    /**
+     * Returns the end datetime of the event
+     *
+     * @return Returns the end datetime of the event
+     */
     public String getTo() {
         return to;
     }
 
+    /**
+     * Returns a human-readable string format
+     *
+     * @return Returns a human-readable string format
+     */
     @Override
     public String toString() {
         return super.toString() + " (from: " + getFrom() + " to: " + getTo() + ")";
     }
-
-    @Override
-    public String toDiskSaveFormat() {
-        return super.toDiskSaveFormat() + " | " + getFrom() + " | " + getTo();
-    }
 }
diff --git a/src/main/java/python/task/Task.java b/src/main/java/python/task/Task.java
index eaea5daee..ac6f05cb1 100644
--- a/src/main/java/python/task/Task.java
+++ b/src/main/java/python/task/Task.java
@@ -1,38 +1,72 @@
 package python.task;
 
+/**
+ * Represents a abstract Task object
+ */
 public abstract class Task {
-    protected String description;
-    protected boolean isDone;
+    private String description;
+    private boolean isDone;
 
+    /**
+     * Constructs <code>Task</code> object
+     *
+     * @param description The description of the task
+     */
     public Task(String description) {
         this.description = description;
         this.isDone = false;
     }
 
+    /**
+     * Returns the status icon of task
+     *
+     * @return Returns the status icon of task
+     */
     public String getStatusIcon() {
         return (isDone() ? "[X]" : "[ ]"); // mark done task with X
     }
 
+    /**
+     * Returns the type icon of task
+     *
+     * @return Returns the type icon of task
+     */
     public abstract String getTypeIcon();
 
+    /**
+     * Returns the description of the task
+     *
+     * @return Returns the description of the task
+     */
     public String getDescription() {
         return description;
     }
 
+    /**
+     * Returns whether the is completed or not
+     *
+     * @return Returns whether the is completed or not
+     */
     public boolean isDone() {
         return isDone;
     }
 
+    /**
+     * Sets the status of completion of the task
+     *
+     * @param done The status to be set
+     */
     public void setDone(boolean done) {
         isDone = done;
     }
 
+    /**
+     * Returns a human-readable string format
+     *
+     * @return Returns a human-readable string format
+     */
     @Override
     public String toString() {
         return getTypeIcon() + getStatusIcon() + " " + getDescription();
     }
-
-    public String toDiskSaveFormat() {
-        return getTypeIcon() + " | " +  getStatusIcon() + " | " + getDescription();
-    }
 }
diff --git a/src/main/java/python/task/TaskList.java b/src/main/java/python/task/TaskList.java
index cf400bcde..61ef84f1e 100644
--- a/src/main/java/python/task/TaskList.java
+++ b/src/main/java/python/task/TaskList.java
@@ -3,37 +3,83 @@
 import java.util.ArrayList;
 import java.util.List;
 
+/**
+ * Encapsulates the functionality of a collection of tasks
+ */
 public class TaskList {
     final static private List<Task> tasks = new ArrayList<>();
 
+    /**
+     * Returns a task on the given index
+     *
+     * @param taskNo Index of the task
+     * @return Task at the index
+     */
     public static Task getTask(int taskNo) {
         return tasks.get(taskNo);
     }
 
+    /**
+     * Returns all the tasks as a <code>List</code>
+     *
+     * @return Returns all the tasks as a <code>List</code>
+     */
     public static List<Task> getTasks() {
         return tasks;
     }
 
+    /**
+     * Returns the number of tasks
+     *
+     * @return Returns the number of tasks
+     */
     public static int getNumberOfTasks() {
         return tasks.size();
     }
 
+    /**
+     * Marks a task
+     *
+     * @param taskNo The index of the task
+     */
     public static void markTask(int taskNo) {
         tasks.get(taskNo).setDone(true);
     }
 
+    /**
+     * Unmarks a task
+     *
+     * @param taskNo The index of the task
+     */
     public static void unmarkTask(int taskNo) {
         tasks.get(taskNo).setDone(false);
     }
 
+    /**
+     * Deletes a task
+     *
+     * @param taskNo The index of the task
+     */
     public static void deleteTask(int taskNo) {
         tasks.remove(taskNo);
     }
 
+    /**
+     * Adds a task
+     *
+     * @param task The task to be added
+     */
     public static void addTask(Task task) {
         tasks.add(task);
     }
 
+    /**
+     * Returns a <code>List</code> of <code>Task</code> of the matching tasks. If a task description
+     * contains the keyword, it is considered a match.
+     *
+     * @param keyword The keyword to be searched
+     * @return Returns a <code>List</code> of <code>Task</code> of the matching tasks
+     */
     public static List<Task> findTask(String keyword) {
         List<Task> matchedTasks = new ArrayList<>();
         for (int taskNo = 0; taskNo < getNumberOfTasks(); taskNo++) {
diff --git a/src/main/java/python/task/Todo.java b/src/main/java/python/task/Todo.java
index b43e34ed4..a1c4e40b0 100644
--- a/src/main/java/python/task/Todo.java
+++ b/src/main/java/python/task/Todo.java
@@ -1,13 +1,26 @@
 package python.task;
 
+/**
+ * Represents a Todo object with a description
+ */
 public class Todo extends Task {
 
-    final static public String TYPE_ICON = "[T]";
+    final static private String TYPE_ICON = "[T]";
 
+    /**
+     * Constructs <code>Todo</code> object
+     *
+     * @param description The description of the task
+     */
     public Todo(String description) {
         super(description);
     }
 
+    /**
+     * Returns the type icon of todo
+     *
+     * @return Returns the type icon of todo
+     */
     @Override
     public String getTypeIcon() {
         return TYPE_ICON;
diff --git a/src/main/java/python/ui/Message.java b/src/main/java/python/ui/Message.java
index 4fb48a0e5..fd0849495 100644
--- a/src/main/java/python/ui/Message.java
+++ b/src/main/java/python/ui/Message.java
@@ -1,5 +1,8 @@
 package python.ui;
 
+/**
+ * Defines string literals for the chatbot responses.
+ */
 public class Message {
     final static String MESSAGE_INTRODUCTION = "Hello! I am a Java Bot Python!";
     final static String MESSAGE_ASK = "What can I do for you?";
diff --git a/src/main/java/python/ui/Ui.java b/src/main/java/python/ui/Ui.java
index 5c2ffc619..2fa39124a 100644
--- a/src/main/java/python/ui/Ui.java
+++ b/src/main/java/python/ui/Ui.java
@@ -3,22 +3,20 @@
 import python.exception.PythonException;
 import python.parser.Command;
 import python.parser.Parser;
-import python.task.Deadline;
-import python.task.Event;
-import python.task.TaskList;
-import python.task.Todo;
-import python.task.Task;
+import python.task.*;
 
 import java.util.List;
 import java.util.Scanner;
 
+/**
+ * Controls the user-chatbot interactions
+ */
 public class Ui {
     private static final Scanner in = new Scanner(System.in);
     final private static String PYTHON_EMOJI = "\uD83D\uDC0D";
     final private static int HORIZONTAL_LINE_LENGTH = 80;
     private String inputLine;
     private String inputCommand;
-
     final private static String PYTHON_ASCII_ART =
             "\t ____        _   _\n" +
                     "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
@@ -36,6 +34,9 @@ private static void addEmojiAndPrint(String message) {
         System.out.printf("\t%s: %s\n", PYTHON_EMOJI, message);
     }
 
+    /**
+     * Welcomes user with some predefined messages
+     */
     public void welcomeUser() {
         System.out.println(PYTHON_ASCII_ART);
         printHorizontalLine();
@@ -45,24 +46,32 @@ public void welcomeUser() {
         printHorizontalLine();
     }
 
-    public void greetGoodBye() {
+    private void greetGoodBye() {
         addEmojiAndPrint(Message.MESSAGE_BYE);
     }
 
-    public void displayTaskCount() {
+    private void displayTaskCount() {
         addEmojiAndPrint("You have " + TaskList.getNumberOfTasks() + " tasks!");
     }
 
-    public void displayTasks(List<Task> tasks) {
+    private void displayTasks(List<Task> tasks) {
         for (int taskNo = 0; taskNo < tasks.size(); taskNo++) {
             System.out.printf("\t\t\t%d. %s\n", taskNo + 1, tasks.get(taskNo));
         }
     }
 
+    /**
+     * Gets the user given raw input
+     */
     public void getUserInput() {
         this.inputLine = in.nextLine();
     }
 
+    /**
+     * Displays the error messages
+     *
+     * @param e The error message
+     */
     public void displayException(Exception e) {
         System.out.println("\tError: " + e.getMessage());
     }
@@ -153,7 +162,6 @@ private void handleDeleteCommand() throws PythonException {
         displayTaskCount();
     }
 
-
     private void handleTodoCommand() throws PythonException {
         String todoDescription;
         try {
@@ -172,7 +180,6 @@ private void handleTodoCommand() throws PythonException {
         displayTaskCount();
     }
 
-
     private void handleDeadlineCommand() throws PythonException {
         String deadlineDetails, deadlineDescription, deadlineBy;
         try {
@@ -236,8 +243,9 @@ private void handleFindCommand() throws PythonException {
 
         List<Task> matchedTasks = TaskList.findTask(keyword);
 
-        if (matchedTasks.isEmpty()) addEmojiAndPrint(Message.MESSAGE_NO_MATCH);
-        else {
+        if (matchedTasks.isEmpty()) {
+            addEmojiAndPrint(Message.MESSAGE_NO_MATCH);
+        } else {
             addEmojiAndPrint(Message.MESSAGE_MATCHES_FOUND);
             displayTasks(matchedTasks);
         }
@@ -251,7 +259,6 @@ private void handleUnknownCommand() throws PythonException {
         addEmojiAndPrint(Message.MESSAGE_UNKNOWN_COMMAND);
     }
 
-
     public void executeLine() throws PythonException {
         printHorizontalLine();
         switch (inputCommand) {

From f61a1b9aa5dbc9dd2bcb05de98359e7662e12e17 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 23:13:19 +0800
Subject: [PATCH 57/59] Add user guide

---
 docs/README.md | 109 ++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 94 insertions(+), 15 deletions(-)

diff --git a/docs/README.md b/docs/README.md
index 8077118eb..b9eeaa290 100644
--- a/docs/README.md
+++ b/docs/README.md
@@ -1,29 +1,108 @@
-# User Guide
+# Python User Guide
+
+**Python** task manager will be a blessing for users with fast typing speed. You can
+add three types of tasks, mark tasks as completed, delete tasks, and if necessary
+find tasks using a keyword!
 
 ## Features 
+Python comes with the following core features:
+* [Add Todo](#add-todo)
+* [Add Deadline](#add-deadline)
+* [Add Event](#add-event)
+* [Mark Task](#mark-task)
+* [Unmark Task](#unmark-task)
+* [Delete Task](#delete-task)
+* [Find Tasks](#find-tasks)
+* [List Tasks](#list-tasks)
+* [Exit](#exit-program)
+
+### Add Todo
+Format:
+`todo [todo description]`
+
+Example of usage:
+`todo buy groceries`
+
+Add a simple todo!
+
+### Add Deadline
+
+Format:
+`deadline [deadline description] /by [due date]`
+
+Example of usage:
+`deadline lab 2 /by friday night`
+
+Add a deadline with due date!
+
+
+### Add Event
+
+Format:
+`event [event description] /from [start date] /to [end date]`
+
+Example of usage:
+`event math exam /from monday 2pm /to monday 4pm`
+
+Add an event to keep track of both start and end times of an activity!
+
+### Mark Task
+
+Format:
+`mark [index of the task - 1 based]`
+
+Example of usage:
+`mark 1`
+
+Mark the task at index as done!
+
+### Unmark Task
+
+Format:
+`unmark [index of the task - 1 based]`
+
+Example of usage:
+`unmark 1`
+
+Unmark the task at index as not done yet!
+
+### Delete Task
+
+Format:
+`delete [index of the task - 1 based]`
+
+Example of usage:
+`delete 1`
+
+Delete the task at the index!
+
+### Find Tasks
 
-### Feature-ABC
+Format:
+`find [keyword]`
 
-Description of the feature.
+Example of usage:
+`find exam`
 
-### Feature-XYZ
+List the tasks that contains the keyword in the description!
 
-Description of the feature.
+### List Tasks
 
-## Usage
+Format:
+`list`
 
-### `Keyword` - Describe action
+Example of usage:
+`list`
 
-Describe the action and its outcome.
+List all the tasks along with completion status and task type!
 
-Example of usage: 
+### Exit Program
 
-`keyword (optional arguments)`
+Format:
+`bye`
 
-Expected outcome:
+Example of usage:
+`bye`
 
-Description of the outcome.
+Greet Python 'bye' to exit the program!
 
-```
-expected output
-```

From 4d7bdfb48c7de259aa91d3bdf676093f4a4df590 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 23:25:57 +0800
Subject: [PATCH 58/59] Reorder and fix formatting

---
 src/main/java/python/Python.java     |  3 +-
 src/main/java/python/ui/Message.java |  4 +--
 src/main/java/python/ui/Ui.java      | 48 ++++++++++++++--------------
 3 files changed, 28 insertions(+), 27 deletions(-)

diff --git a/src/main/java/python/Python.java b/src/main/java/python/Python.java
index c7eaf8897..a1a476184 100644
--- a/src/main/java/python/Python.java
+++ b/src/main/java/python/Python.java
@@ -5,6 +5,7 @@
 
 public class Python {
     static final private Ui ui = new Ui();
+
     public static void main(String[] args) {
         ui.welcomeUser();
         do {
@@ -15,6 +16,6 @@ public static void main(String[] args) {
             } catch (PythonException e) {
                 ui.displayException(e);
             }
-        } while(!ui.isExit());
+        } while (!ui.isExit());
     }
 }
diff --git a/src/main/java/python/ui/Message.java b/src/main/java/python/ui/Message.java
index fd0849495..53bb71f9a 100644
--- a/src/main/java/python/ui/Message.java
+++ b/src/main/java/python/ui/Message.java
@@ -18,13 +18,13 @@ public class Message {
             "Command must have /by clause followed by time its due!";
     final static String MESSAGE_FUTURE_JOKE = "Are you from the future?";
     final static String MESSAGE_PAST_JOKE = "Are you from the past?";
+    final static String MESSAGE_UNMARK_TASK_JOKE = "Alas! Only the completed tasks can be unmarked!";
+    final static String MESSAGE_EMPTY_COMMAND_JOKE = "Nothing for me?";
     final static String MESSAGE_TASK_ALREADY_DONE = "Task is already done!";
     final static String MESSAGE_CONGRATUALTE = "Good job completing the task!";
-    final static String MESSAGE_UNMARK_TASK_JOKE = "Alas! Only the completed tasks can be unmarked!";
     final static String MESSAGE_TASK_IDLE = "Task is already sitting idle. Get started...!!!";
     final static String MESSAGE_MISTAKE_CONSOLATION = "Its okay! To err is human! Unmarked!";
     final static String MESSAGE_DELETE_CONFIRMATION = "Okay. Deleting this task...!";
-    final static String MESSAGE_EMPTY_COMMAND_JOKE = "Nothing for me?";
     final static String MESSAGE_UNKNOWN_COMMAND = "I cannot understand the command!";
     final static String MESSAGE_NEW_TODO = "New Todo! You have added this todo:";
     final static String MESSAGE_NEW_DEADLINE = "New Deadline! You have added this deadline:";
diff --git a/src/main/java/python/ui/Ui.java b/src/main/java/python/ui/Ui.java
index 2fa39124a..41261af22 100644
--- a/src/main/java/python/ui/Ui.java
+++ b/src/main/java/python/ui/Ui.java
@@ -12,13 +12,13 @@
  * Controls the user-chatbot interactions
  */
 public class Ui {
-    private static final Scanner in = new Scanner(System.in);
+    private static final Scanner IN = new Scanner(System.in);
     final private static String PYTHON_EMOJI = "\uD83D\uDC0D";
     final private static int HORIZONTAL_LINE_LENGTH = 80;
     private String inputLine;
     private String inputCommand;
     final private static String PYTHON_ASCII_ART =
-            "\t ____        _   _\n" +
+                    "\t ____        _   _\n" +
                     "\t|  _ \\ _   _| |_| |__   ___  _ __\n" +
                     "\t| |_) | | | | __|  _ \\ / _ \\|  _ \\\n" +
                     "\t|  __/| |_| | |_| | | | (_) | | | |\n" +
@@ -60,26 +60,6 @@ private void displayTasks(List<Task> tasks) {
         }
     }
 
-    /**
-     * Gets the user given raw input
-     */
-    public void getUserInput() {
-        this.inputLine = in.nextLine();
-    }
-
-    /**
-     * Displays the error messages
-     *
-     * @param e The error message
-     */
-    public void displayException(Exception e) {
-        System.out.println("\tError: " + e.getMessage());
-    }
-
-    public void parseLine() {
-        this.inputCommand = Parser.extractCommandFromInputLine(inputLine);
-    }
-
     private void handleByeCommand() {
         greetGoodBye();
     }
@@ -110,6 +90,7 @@ private void handleMarkCommand() throws PythonException {
         }
 
         TaskList.markTask(taskNo);
+
         addEmojiAndPrint(Message.MESSAGE_CONGRATUALTE);
         addEmojiAndPrint(TaskList.getTask(taskNo).toString());
     }
@@ -158,6 +139,7 @@ private void handleDeleteCommand() throws PythonException {
 
         addEmojiAndPrint(Message.MESSAGE_DELETE_CONFIRMATION);
         addEmojiAndPrint(TaskList.getTask(taskNo).toString());
+
         TaskList.deleteTask(taskNo);
         displayTaskCount();
     }
@@ -169,11 +151,9 @@ private void handleTodoCommand() throws PythonException {
         } catch (ArrayIndexOutOfBoundsException e) {
             throw new PythonException(Message.MESSAGE_DESC_AFTER_COMMAND);
         }
-
         addEmojiAndPrint(Message.MESSAGE_NEW_TODO);
 
         Todo todo = new Todo(todoDescription);
-
         TaskList.addTask(todo);
 
         addEmojiAndPrint(todo.toString());
@@ -259,6 +239,26 @@ private void handleUnknownCommand() throws PythonException {
         addEmojiAndPrint(Message.MESSAGE_UNKNOWN_COMMAND);
     }
 
+    /**
+     * Gets the user given raw input
+     */
+    public void getUserInput() {
+        this.inputLine = IN.nextLine();
+    }
+
+    /**
+     * Displays the error messages
+     *
+     * @param e The error message
+     */
+    public void displayException(Exception e) {
+        System.out.println("\tError: " + e.getMessage());
+    }
+
+    public void parseLine() {
+        this.inputCommand = Parser.extractCommandFromInputLine(inputLine);
+    }
+
     public void executeLine() throws PythonException {
         printHorizontalLine();
         switch (inputCommand) {

From 32183698fcc290b2e39a6c02f748325c0b95dc29 Mon Sep 17 00:00:00 2001
From: nihalzp <81457724+nihalzp@users.noreply.github.com>
Date: Fri, 6 Oct 2023 23:31:19 +0800
Subject: [PATCH 59/59] Do not print task count at start

---
 src/main/java/python/ui/Ui.java | 1 -
 text-ui-test/EXPECTED.TXT       | 1 -
 2 files changed, 2 deletions(-)

diff --git a/src/main/java/python/ui/Ui.java b/src/main/java/python/ui/Ui.java
index 41261af22..d74cf563e 100644
--- a/src/main/java/python/ui/Ui.java
+++ b/src/main/java/python/ui/Ui.java
@@ -41,7 +41,6 @@ public void welcomeUser() {
         System.out.println(PYTHON_ASCII_ART);
         printHorizontalLine();
         addEmojiAndPrint(Message.MESSAGE_INTRODUCTION);
-        displayTaskCount();
         addEmojiAndPrint(Message.MESSAGE_ASK);
         printHorizontalLine();
     }
diff --git a/text-ui-test/EXPECTED.TXT b/text-ui-test/EXPECTED.TXT
index 7df3c0b5c..c034527aa 100644
--- a/text-ui-test/EXPECTED.TXT
+++ b/text-ui-test/EXPECTED.TXT
@@ -6,7 +6,6 @@
 	       |___/
 	————————————————————————————————————————————————————————————————————————————————
 	🐍: Hello! I am a Java Bot Python!
-	🐍: You have 0 tasks!
 	🐍: What can I do for you?
 	————————————————————————————————————————————————————————————————————————————————
 	————————————————————————————————————————————————————————————————————————————————