cardano-wasm demo: multi-wallet management

.changes/20260718_cardano_wasm_demo_wallets.yml

@@ -0,0 +1,9 @@
+project: cardano-wasm
+
+pr: 1270
+
+kind:
+  - feature
+
+description: |
+  Demo: multi-wallet management (generate/restore, aliases, network switch with address re-derivation).

cardano-wasm/demo/src/Format.elm

@@ -0,0 +1,97 @@
+module Format exposing (ada, adaToLovelace, amountError, lovelaceToAda, orDefault, shorten)
+
+{-| String formatting and parsing: ada ↔ lovelace, abbreviation, small text helpers.
+-}
+
+
+{-| Parse a user-typed ADA amount ("1.5" → 1500000 lovelace).
+-}
+adaToLovelace : String -> Maybe Int
+adaToLovelace s =
+    String.toFloat (String.trim s)
+        |> Maybe.map (\f -> round (f * 1.0e6))
+
+
+{-| True when a typed amount is non-empty but not a valid positive number (e.g. "1,5").
+-}
+amountError : String -> Bool
+amountError s =
+    if String.trim s == "" then
+        False
+
+    else
+        case adaToLovelace s of
+            Just n ->
+                n <= 0
+
+            Nothing ->
+                True
+
+
+lovelaceToAda : Int -> String
+lovelaceToAda l =
+    let
+        sign =
+            if l < 0 then
+                "-"
+
+            else
+                ""
+
+        a =
+            abs l
+
+        whole =
+            a // 1000000
+
+        frac =
+            String.padLeft 6 '0' (String.fromInt (modBy 1000000 a)) |> stripTrailingZeros
+    in
+    sign
+        ++ String.fromInt whole
+        ++ (if frac == "" then
+                ""
+
+            else
+                "." ++ frac
+           )
+
+
+ada : Int -> String
+ada l =
+    lovelaceToAda l ++ " ₳"
+
+
+stripTrailingZeros : String -> String
+stripTrailingZeros s =
+    String.foldr
+        (\c ( acc, trimming ) ->
+            if trimming && c == '0' then
+                ( acc, True )
+
+            else
+                ( String.cons c acc, False )
+        )
+        ( "", True )
+        s
+        |> Tuple.first
+
+
+{-| Abbreviate long identifiers (addresses, keys, hashes) for display.
+-}
+shorten : String -> String
+shorten s =
+    if String.length s > 22 then
+        String.left 12 s ++ "…" ++ String.right 6 s
+
+    else
+        s
+
+
+orDefault : String -> String -> String
+orDefault d s =
+    if String.trim s == "" then
+        d
+
+    else
+        s

cardano-wasm/demo/src/Main.elm

@@ -1,24 +1,42 @@
 module Main exposing (main)
 
-{-| Placeholder page: proves the demo build pipeline and that the cardano-wasm
-engine loads in the browser (web/ports.js only starts this application after
-`initialise()` has succeeded). The wallet application itself follows.
+{-| Entry point — wires The Elm Architecture together. The interesting code lives in:
+
+  - Types — every data type, the Model and the Msg
+  - State — initial state, derived queries, small updaters
+  - Update — the controller (one branch per Msg)
+  - View — the whole UI
+  - Wasm — the cardano-wasm boundary (port commands + decoders)
+  - Net / Format — static tables and pure utilities
+  - Ports — the raw port declarations (JS side: web/ports.js)
+
 -}
 
-import Html exposing (Html, div, h3, p, text)
-import Html.Attributes exposing (class, style)
+import Browser
+import Ports
+import State exposing (init)
+import Types exposing (..)
+import Update exposing (update)
+import View exposing (view)
+import Wasm
 
 
-main : Html msg
-main =
-    div [ class "grid" ]
-        [ div [ class "col" ] []
-        , div [ class "col" ]
-            [ div [ class "card", style "margin-top" "40px" ]
-                [ h3 [] [ text "cardano-wasm wallet demo" ]
-                , p [] [ text "✓ the cardano-wasm engine loaded successfully in your browser." ]
-                , p [ class "muted small" ] [ text "The wallet application will appear here as it is built up in subsequent changes." ]
-                ]
-            ]
-        , div [ class "col" ] []
+{-| Each incoming port is decoded by Wasm and dispatched as a Msg.
+-}
+subscriptions : Model -> Sub Msg
+subscriptions _ =
+    Sub.batch
+        [ Ports.wasmWalletGenerated (Wasm.decodeResult Wasm.genDecoder >> GotGeneratedWallet)
+        , Ports.wasmWalletRestored (Wasm.decodeResult Wasm.genDecoder >> GotRestoredWallet)
+        , Ports.wasmAddressesDerived (Wasm.decodeResult Wasm.addrsDecoder >> GotDerivedAddresses)
         ]
+
+
+main : Program () Model Msg
+main =
+    Browser.element
+        { init = init
+        , update = update
+        , view = view
+        , subscriptions = subscriptions
+        }

cardano-wasm/demo/src/Net.elm

@@ -0,0 +1,108 @@
+module Net exposing
+    ( blockfrostBase
+    , cliFlag
+    , explorerTx
+    , faucetUrl
+    , netMagic
+    , netName
+    , netTag
+    )
+
+{-| Static tables for the three networks. Pure data — no logic lives here.
+-}
+
+import Types exposing (..)
+
+
+
+-- NETWORKS
+
+
+netName : Network -> String
+netName n =
+    case n of
+        Mainnet ->
+            "Mainnet"
+
+        Preprod ->
+            "Preprod"
+
+        Preview ->
+            "Preview"
+
+
+{-| Lowercase identifier used on the JS side of the ports.
+-}
+netTag : Network -> String
+netTag n =
+    case n of
+        Mainnet ->
+            "mainnet"
+
+        Preprod ->
+            "preprod"
+
+        Preview ->
+            "preview"
+
+
+netMagic : Network -> String
+netMagic n =
+    case n of
+        Mainnet ->
+            "764824073"
+
+        Preprod ->
+            "1"
+
+        Preview ->
+            "2"
+
+
+blockfrostBase : Network -> String
+blockfrostBase n =
+    case n of
+        Mainnet ->
+            "https://cardano-mainnet.blockfrost.io/api/v0"
+
+        Preprod ->
+            "https://cardano-preprod.blockfrost.io/api/v0"
+
+        Preview ->
+            "https://cardano-preview.blockfrost.io/api/v0"
+
+
+explorerTx : Network -> String
+explorerTx n =
+    case n of
+        Mainnet ->
+            "https://cardanoscan.io/"
+
+        Preprod ->
+            "https://preprod.cardanoscan.io/"
+
+        Preview ->
+            "https://preview.cardanoscan.io/"
+
+
+faucetUrl : Network -> Maybe String
+faucetUrl n =
+    case n of
+        Mainnet ->
+            Nothing
+
+        _ ->
+            Just "https://docs.cardano.org/cardano-testnets/tools/faucet/"
+
+
+cliFlag : Network -> String
+cliFlag n =
+    case n of
+        Mainnet ->
+            "--mainnet"
+
+        Preprod ->
+            "--testnet-magic 1"
+
+        Preview ->
+            "--testnet-magic 2"

cardano-wasm/demo/src/Ports.elm

@@ -0,0 +1,38 @@
+port module Ports exposing (..)
+
+{-| The raw port declarations — the only holes in the wall between Elm and
+JavaScript. The JS side lives in web/ports.js. Payloads are untyped JSON;
+Wasm.elm encodes the requests and decodes the replies.
+-}
+
+import Json.Decode as D
+import Json.Encode as E
+
+
+
+-- PORTS (out → cardano-wasm / clipboard)
+
+
+port wasmGenerateWallet : E.Value -> Cmd msg
+
+
+port wasmRestoreWallet : E.Value -> Cmd msg
+
+
+port wasmDeriveAddresses : E.Value -> Cmd msg
+
+
+port clipboardWrite : String -> Cmd msg
+
+
+
+-- PORTS (in ← cardano-wasm)
+
+
+port wasmWalletGenerated : (D.Value -> msg) -> Sub msg
+
+
+port wasmWalletRestored : (D.Value -> msg) -> Sub msg
+
+
+port wasmAddressesDerived : (D.Value -> msg) -> Sub msg