Modularize and fix code

frontend/src/websocket.ts

@@ -0,0 +1,22 @@
+import { currentUser } from "./auth";
+import { addMessage } from "./chat";
+import { API_FULL_BASE_URL } from "./config";
+import type { WebSocketMessage, Message } from "./types";
+
+
+export const websocket = new WebSocket(`ws://${API_FULL_BASE_URL}/chat/ws`);
+
+// --------------
+// Initialization
+// --------------
+
+websocket.addEventListener("message", (e) => {
+    const message: WebSocketMessage = JSON.parse(e.data);
+    switch (message.type) {
+        case "newMessage": {
+            const newMessage: Message = message.data;
+            addMessage(newMessage, newMessage.username == currentUser!.username);
+            break;
+        }
+    }
+});