Chirag: Update pagination to be applicable only when specified

src/controllers/eventController.js

@@ -10,51 +10,105 @@ const updateEventStatus = (event) => {
   return event.status;
 };
 
-const getEvents = async (req, res) => {
-  const { page = 1, limit = 9, type = '', location = '', sortBy = 'date' } = req.query;
+const VALID_TYPES = new Set(['Workshop', 'Meeting', 'Webinar', 'Social Gathering']);
+const VALID_LOCATIONS = new Set(['Virtual', 'In person', 'TBD']);
+const VALID_SORT_FIELDS = new Set(['date', 'title', 'type', 'location', 'currentAttendees']);
 
-  try {
-    const validSortFields = ['date', 'title', 'type', 'location', 'currentAttendees'];
-    const sortField = validSortFields.includes(sortBy) ? sortBy : 'date';
+function validateQuery({ type, location, sortBy }) {
+  if (type && !VALID_TYPES.has(type)) {
+    throw new Error('Invalid Type of Event.');
+  }
 
-    const query = { isActive: true };
-    if (type) query.type = type;
-    if (location) query.location = location;
+  if (location && !VALID_LOCATIONS.has(location)) {
+    throw new Error('Invalid Location for the Event.');
+  }
 
-    const pageNumber = Math.max(1, Number(page));
-    const limitNumber = Math.max(1, Number(limit));
+  if (sortBy && !VALID_SORT_FIELDS.has(sortBy)) {
+    throw new Error('Invalid Sort Field.');
+  }
+}
 
-    const totalEvents = await Event.countDocuments(query);
-    let events = await Event.find(query)
-      .populate('resources.userID')
-      .sort({ [sortField]: 1 })
-      .skip((pageNumber - 1) * limitNumber)
-      .limit(limitNumber);
+function buildSafeQuery(location, type) {
+  const query = { isActive: true };
 
-    events = events.map((event) => {
-      event.status = updateEventStatus(event);
+  if (location === 'Virtual') {
+    query.location = 'Virtual';
+  } else if (location === 'In person') {
+    query.location = 'In person';
+  } else if (location === 'TBD') {
+    query.location = 'TBD';
+  }
 
-      const eventObj = event.toObject();
+  if (type === 'Workshop') {
+    query.type = 'Workshop';
+  } else if (type === 'Meeting') {
+    query.type = 'Meeting';
+  } else if (type === 'Webinar') {
+    query.type = 'Webinar';
+  } else if (type === 'Social Gathering') {
+    query.type = 'Social Gathering';
+  }
 
-      eventObj.waitlistCount = event.waitlist?.length || 0;
+  return query;
+}
 
-      eventObj.waitlistEnabled = event.currentAttendees >= event.maxAttendees;
+function getPagination(page, limit, total) {
+  if (!page || !limit) {
+    return {
+      pageNumber: 1,
+      limitNumber: total,
+      skip: 0,
+    };
+  }
 
-      const { userId } = req.query;
+  const pageNumber = Math.max(1, Number(page));
+  const limitNumber = Math.max(1, Number(limit));
 
-      if (userId && mongoose.Types.ObjectId.isValid(userId)) {
-        const index = event.waitlist.findIndex(
-          (entry) => entry.userId?.toString() === userId.toString(),
-        );
+  return {
+    pageNumber,
+    limitNumber,
+    skip: (pageNumber - 1) * limitNumber,
+  };
+}
 
-        eventObj.userWaitlistPosition = index !== -1 ? index + 1 : null;
-      }
+function formatEvent(event, userId) {
+  event.status = updateEventStatus(event);
 
-      return eventObj;
-    });
+  const eventObj = event.toObject();
+  const waitlist = Array.isArray(event.waitlist) ? event.waitlist : [];
+
+  eventObj.waitlistCount = waitlist.length;
+  eventObj.waitlistEnabled = event.currentAttendees >= event.maxAttendees;
+
+  if (userId) {
+    const index = waitlist.findIndex((entry) => entry.userId?.toString() === userId.toString());
+
+    eventObj.userWaitlistPosition = index !== -1 ? index + 1 : null;
+  }
+
+  return eventObj;
+}
+
+const getEvents = async function (req, res) {
+  try {
+    const { page, limit, type, location, sortBy } = req.query;
+
+    validateQuery({ type, location, sortBy });
+
+    const safeQuery = buildSafeQuery(location, type);
+    const totalEvents = await Event.countDocuments(safeQuery);
+    const { pageNumber, limitNumber, skip } = getPagination(page, limit, totalEvents);
+
+    const events = await Event.find(safeQuery)
+      .populate('resources.userID')
+      .sort(sortBy ? { [sortBy]: 1 } : {})
+      .skip(skip)
+      .limit(limitNumber);
+
+    const formattedEvents = events.map((event) => formatEvent(event, safeQuery.userId));
 
     res.json({
-      events,
+      events: formattedEvents,
       pagination: {
         total: totalEvents,
         totalPages: Math.ceil(totalEvents / limitNumber),
@@ -63,7 +117,14 @@ const getEvents = async (req, res) => {
       },
     });
   } catch (error) {
-    res.status(500).json({ error: 'Failed to fetch events', details: error.message });
+    if (error.message.startsWith('Invalid')) {
+      return res.status(400).send(error.message);
+    }
+
+    res.status(500).json({
+      error: 'Failed to fetch events',
+      details: error.message,
+    });
   }
 };