/// <reference lib="deno.ns" />
import { assertEquals } from "jsr:@std/assert";
import { startServer } from "./deno.ts";

const hostname = "0.0.0.0";
const port = 8042;
const href = `ws://${hostname}:${port}`;

async function connect(url: string): Promise<[WebSocket, string[]]> {
	return new Promise((resolve) => {
		const messages: string[] = [];
		const socket = new WebSocket(url);

		socket.onmessage = ({ data }) => {
			messages.push(data);
		};
		socket.onopen = () => resolve([socket, messages]);
	});
}

function close(socket: WebSocket): Promise<void> {
	return new Promise((resolve) => {
		if (socket.readyState === WebSocket.CLOSED) {
			return resolve();
		}
		socket.onclose = () => resolve();
		socket.close();
	});
}

function setup(
	fn: (ctx: Deno.TestContext) => Promise<void>,
): (ctx: Deno.TestContext) => Promise<void> {
	return async (ctx) => {
		const shutdown = startServer(hostname, port);
		try {
			await fn(ctx);
		} finally {
			await shutdown();
		}
	};
}

Deno.test(
	"broadcasts a message on connect to all clients",
	setup(async () => {
		const [s1, m1] = await connect(href);
		const [s2, m2] = await connect(href);

		assertEquals(m1, ["1 has joined!", "2 has joined!"]);
		assertEquals(m2, ["2 has joined!"]);

		await close(s2);
		await close(s1);
	}),
);

Deno.test(
	"removes a client from broadcast after it disconnects",
	setup(async () => {
		const [s1, m1] = await connect(href);
		const [s2, m2] = await connect(href);
		const [s3, m3] = await connect(href);

		m1.length = 0;
		m2.length = 0;
		m3.length = 0;

		await close(s3);

		assertEquals(m1, ["3 has left!"]);
		assertEquals(m2, ["3 has left!"]);
		assertEquals(m3, []);

		await close(s2);
		await close(s1);
	}),
);