frontend/src/lib/stores/websocket.js

import { writable } from 'svelte/store';
import { playSound } from '$utils/helpers.js';

function createWebSocketStore() {
	const { subscribe, set, update } = writable({
		connected: false,
		ws: null
	});

	let ws = null;
	let reconnectTimer = null;
	let listeners = {};

	function connect(token) {
		if (ws && ws.readyState === WebSocket.OPEN) return;

		const protocol = window.location.protocol === 'https:' ? 'wss' : 'ws';
		const host = window.location.host;
		const url = `${protocol}://${host}/ws?token=${token}`;

		ws = new WebSocket(url);

		ws.onopen = () => {
			console.log('[WS] Connected');
			update((s) => ({ ...s, connected: true, ws }));
			clearTimeout(reconnectTimer);
		};

		ws.onmessage = (event) => {
			try {
				const msg = JSON.parse(event.data);
				const { channel, event: evt, data } = msg;

				// Dispatch to registered listeners
				const key = `${channel}:${evt}`;
				if (listeners[key]) {
					listeners[key].forEach((fn) => fn(data));
				}

				// Wildcard channel listeners
				if (listeners[`*:${evt}`]) {
					listeners[`*:${evt}`].forEach((fn) => fn(data, channel));
				}

				// Play sound for new orders/KOTs
				if (evt === 'new_order' || evt === 'new_kot') {
					playSound('order');
				}
			} catch {
				// Ignore parse errors
			}
		};

		ws.onclose = () => {
			console.log('[WS] Disconnected, reconnecting in 3s...');
			update((s) => ({ ...s, connected: false, ws: null }));
			reconnectTimer = setTimeout(() => connect(token), 3000);
		};

		ws.onerror = () => {
			ws.close();
		};
	}

	function disconnect() {
		clearTimeout(reconnectTimer);
		if (ws) {
			ws.close();
			ws = null;
		}
		set({ connected: false, ws: null });
		listeners = {};
	}

	function on(channel, event, callback) {
		const key = `${channel}:${event}`;
		if (!listeners[key]) listeners[key] = [];
		listeners[key].push(callback);

		// Return unsubscribe function
		return () => {
			listeners[key] = listeners[key].filter((fn) => fn !== callback);
		};
	}

	function send(channel, event, data) {
		if (ws && ws.readyState === WebSocket.OPEN) {
			ws.send(JSON.stringify({ channel, event, data }));
		}
	}

	return {
		subscribe,
		connect,
		disconnect,
		on,
		send
	};
}

export const wsStore = createWebSocketStore();