1 files changed, 89 insertions, 0 deletions
diff --git a/packages/frontend/src/lib/ws.svelte.ts b/packages/frontend/src/lib/ws.svelte.ts
new file mode 100644
index 0000000..76c7ef5
--- /dev/null
+++ b/packages/frontend/src/lib/ws.svelte.ts
@@ -0,0 +1,89 @@
+import { config } from "./config.js";
+import type { AgentEvent, ConnectionStatus } from "./types.js";
+
+type EventCallback = (event: AgentEvent) => void;
+
+function createWebSocketClient(url: string) {
+	let connectionStatus: ConnectionStatus = $state("disconnected");
+	let ws: WebSocket | null = null;
+	let reconnectDelay = 1000;
+	let reconnectTimer: ReturnType<typeof setTimeout> | null = null;
+	let manualDisconnect = false;
+	const callbacks: EventCallback[] = [];
+
+	function connect() {
+		if (ws && (ws.readyState === WebSocket.OPEN || ws.readyState === WebSocket.CONNECTING)) {
+			return;
+		}
+		manualDisconnect = false;
+		connectionStatus = "connecting";
+		ws = new WebSocket(url);
+
+		ws.onopen = () => {
+			connectionStatus = "connected";
+			reconnectDelay = 1000;
+		};
+
+		ws.onmessage = (event: MessageEvent) => {
+			try {
+				const data = JSON.parse(event.data as string) as AgentEvent;
+				for (const cb of callbacks) {
+					cb(data);
+				}
+			} catch {
+				// ignore malformed messages
+			}
+		};
+
+		ws.onclose = () => {
+			connectionStatus = "disconnected";
+			ws = null;
+			if (!manualDisconnect) {
+				scheduleReconnect();
+			}
+		};
+
+		ws.onerror = () => {
+			ws?.close();
+		};
+	}
+
+	function scheduleReconnect() {
+		if (reconnectTimer) clearTimeout(reconnectTimer);
+		reconnectTimer = setTimeout(() => {
+			reconnectTimer = null;
+			connect();
+		}, reconnectDelay);
+		reconnectDelay = Math.min(reconnectDelay * 2, 10000);
+	}
+
+	function disconnect() {
+		manualDisconnect = true;
+		if (reconnectTimer) {
+			clearTimeout(reconnectTimer);
+			reconnectTimer = null;
+		}
+		ws?.close();
+		ws = null;
+		connectionStatus = "disconnected";
+	}
+
+	function onEvent(callback: EventCallback) {
+		callbacks.push(callback);
+		return () => {
+			const idx = callbacks.indexOf(callback);
+			if (idx !== -1) callbacks.splice(idx, 1);
+		};
+	}
+
+	return {
+		get connectionStatus() {
+			return connectionStatus;
+		},
+		connect,
+		disconnect,
+		onEvent,
+	};
+}
+
+export const wsClient = createWebSocketClient(config.wsUrl);