Added Websockets

src/lib/websocket.svelte.ts

@@ -0,0 +1,106 @@
+export enum SocketConnectionType {
+    NONE,
+    HOST,
+    DISPLAY
+}
+
+const messages: string[] = $state([]);
+let connectionType = $state(SocketConnectionType.NONE);
+
+let socket: WebSocket | undefined;
+
+const connectAsHost = () => {
+    if (socket !== undefined) return;
+    socket = new WebSocket("ws://127.0.0.1:12345");
+    socket.addEventListener("open", onOpen(SocketConnectionType.HOST));
+    socket.addEventListener("message", onFirstMessage);
+    socket.addEventListener("close", onClose);
+    socket.addEventListener("error", onError);
+};
+
+const connectAsDisplay = () => {
+    if (socket !== undefined) return;
+    socket = new WebSocket("ws://127.0.0.1:12345");
+    socket.addEventListener("open", onOpen(SocketConnectionType.DISPLAY));
+    socket.addEventListener("message", onFirstMessage);
+};
+
+const sendMessage = (obj: unknown) => {
+    if (socket === undefined) return;
+    if (socket.readyState <= 1) {
+        try {
+            socket.send(JSON.stringify(obj));
+        } catch {
+            console.error(`Could not send ${obj}`);
+        }
+    }
+};
+
+function onOpen(type: SocketConnectionType) {
+    return (event: Event) => {
+        console.log("Connection established");
+        console.log(event);
+        if (socket === undefined) return;
+        socket.send(type == SocketConnectionType.HOST ? "HOST" : "DISPLAY");
+    };
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function onFirstMessage(event: MessageEvent<any>) {
+    if (socket === undefined) return;
+    console.log(event.data);
+    if (event.data === "HOST") {
+        connectionType = SocketConnectionType.HOST;
+        socket.removeEventListener("message", onFirstMessage);
+        socket.addEventListener("message", onMessage);
+    } else if (event.data === "DISPLAY") {
+        connectionType = SocketConnectionType.DISPLAY;
+        socket.removeEventListener("message", onFirstMessage);
+        socket.addEventListener("message", onMessage);
+    } else {
+        console.error("Failed to register");
+        socket.close();
+        socket = undefined;
+    }
+}
+
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function onMessage(event: MessageEvent<any>) {
+    messages.push(event.data);
+}
+
+function onClose(event: CloseEvent) {
+    console.log("Connection closed");
+    console.log(event);
+    connectionType = SocketConnectionType.NONE;
+    if (socket === undefined) return;
+    socket.close();
+    socket = undefined;
+}
+
+function onError(event: Event) {
+    console.error("Websocket error occured");
+    console.error(event);
+    connectionType = SocketConnectionType.NONE;
+    if (socket === undefined) return;
+    socket.close();
+    socket = undefined;
+}
+
+export default {
+    get message() {
+        return messages[0];
+    },
+    nextMessage() {
+        return messages.shift();
+    },
+    get messageNum() {
+        return messages.length;
+    },
+    get connectionType() {
+        return connectionType;
+    },
+    sendMessage,
+    connectAsHost,
+    connectAsDisplay
+};