import { DurableObject } from "cloudflare:workers";

/** `?url=<target>` fetches it; with `&ws=1`, opens a WebSocket there and reports the echo of "hello". */
export class App extends DurableObject {
	async fetch(request) {
		const params = new URL(request.url).searchParams;
		const target = params.get("url");
		try {
			if (!params.has("ws")) return new Response(`got: ${await (await fetch(target)).text()}\n`);
			const resp = await fetch(target, { headers: { Upgrade: "websocket" } });
			const ws = resp.webSocket;
			if (!ws) return new Response(`no websocket: ${resp.status} ${await resp.text()}`);
			ws.accept();
			const reply = new Promise((resolve) => ws.addEventListener("message", (e) => resolve(e.data)));
			ws.send("hello");
			const got = await reply;
			ws.close();
			return new Response(`echo: ${got}\n`);
		} catch (e) {
			return new Response(`refused: ${e.message}\n`);
		}
	}
}