export class Subscription_Endpoint extends EventTarget {

	async connect(path) {
		const wsProtocol = location.protocol === 'https:' ? 'wss:' : 'ws:';
		const wsUrl = `${wsProtocol}//${location.host}${path}`;

		const ws = new WebSocket(wsUrl);

		await new Promise((resolve, reject) => {
			ws.addEventListener('open', resolve, { once: true });
			ws.addEventListener('error', reject, { once: true });
		});

		ws.addEventListener('message', ev => {
			this.dispatchEvent(new CustomEvent('message', { detail: ev.data }));
		});

		ws.addEventListener('close', () => {
			this.dispatchEvent(new Event('close'));
		});

		ws.addEventListener('error', err => {
			this.dispatchEvent(new CustomEvent('error', { detail: err }));
		});

		this.ws = ws;
		return ws;
	}

	subscribe(resource) {
		const { ws } = this;
		ws.send(JSON.stringify({
			cmd: 'subscribe',
			resource
		}));
	}



}