Adding a playersStore

The playerStore can be useful to get the details of a given player from its ID.

front/src/Stores/PlayersStore.ts

@@ -0,0 +1,43 @@
+import { writable } from "svelte/store";
+import type {PlayerInterface} from "../Phaser/Game/PlayerInterface";
+import type {RoomConnection} from "../Connexion/RoomConnection";
+
+/**
+ * A store that contains the list of players currently known.
+ */
+function createPlayersStore() {
+    let players = new Map<number, PlayerInterface>();
+
+    const { subscribe, set, update } = writable(players);
+
+    return {
+        subscribe,
+        connectToRoomConnection: (roomConnection: RoomConnection) => {
+            players = new Map<number, PlayerInterface>();
+            set(players);
+            roomConnection.onUserJoins((message) => {
+                update((users) => {
+                    users.set(message.userId, {
+                        userId: message.userId,
+                        name: message.name,
+                        characterLayers: message.characterLayers,
+                        visitCardUrl: message.visitCardUrl,
+                        companion: message.companion,
+                    });
+                    return users;
+                });
+            });
+            roomConnection.onUserLeft((userId) => {
+                update((users) => {
+                    users.delete(userId);
+                    return users;
+                });
+            });
+        },
+        getPlayerById(userId: number): PlayerInterface|undefined {
+            return players.get(userId);
+        }
+    };
+}
+
+export const playersStore = createPlayersStore();