import { createServer } from "node:http";
import process from "node:process";
import { WebSocketServer } from "ws";

const server = createServer();
const requests: string[] = [];
const clients = new Set<string>();

server.on("listening", () => {
	const address = server.address();

	if (!address || typeof address !== "object") {
		throw new Error("[test server] Unexpected address assigned");
	}

	const port = address.port;
	console.log(`[test server] Listening at port ${port}`);
	process.send?.(`ready:${port}`);
});

server.on("upgrade", (req, socket) => {
	const url = new URL(`http://example.com${req.url}`);
	const clientId = url.searchParams.get("clientId");
	let shouldDeny = url.searchParams.get("deny") === "always";

	if (clientId) {
		const denyPattern = url.searchParams.get("deny");
		requests.push(clientId);

		if (!shouldDeny && denyPattern) {
			const requestIndex = requests.reduce(
				(count, req) => (req === clientId ? count + 1 : count),
				-1,
			);
			shouldDeny = denyPattern[requestIndex] === "1";
		}
	}

	if (shouldDeny) {
		console.log("[test server] Upgrade request denied");
		socket.destroy();
	}
});

server.on("close", () => {
	console.log("[test server] Server stopped");
	clients.clear();
});

const wss = new WebSocketServer({ server });

wss.on("connection", (ws, req) => {
	const url = new URL(`http://example.com${req.url}`);
	const clientId = url.searchParams.get("clientId");
	const greet = url.searchParams.get("hello");

	console.log(`[test server] Incoming connection ${clientId ?? "(no id)"}`);

	if (clientId) {
		clients.add(clientId);
	}

	if (greet) {
		ws.send(`Hello, ${greet}`);
	}

	ws.on("message", (data) => {
		const message = data.toString("utf-8");

		if (message === "close") {
			ws.close(1000, "client requested to close");
		} else {
			ws.send(message);
		}
	});

	ws.on("close", (code) => {
		if (clientId) {
			clients.delete(clientId);
		}

		console.log(
			`[test server] Connection ${clientId ?? "(no id)"} closed with code ${code}`,
		);
	});
});

server.listen(0);

process.on("message", (message) => {
	if (typeof message === "string") {
		const status = clients.has(message) ? "connected" : "disconnected";
		const requestCount = requests.reduce(
			(count, req) => (req === message ? count + 1 : count),
			0,
		);
		process.send?.(`${message}:${status}:${requestCount}`);
	}
});

process.on("SIGINT", () => {
	console.log("[test server] Gracefully stopping...");
	wss.clients.forEach((ws) => ws.close(1001, "Test server stopped"));
	server.close();
	process.exit(0);
});