// OxiLink signalling relay - the entire server.
// It relays small opaque strings between at most two peers for at most five
// minutes, then dies. No media, no logs, no accounts, no persistence.
// Copyright 2026 COOLJAPAN OU (Team Kitasan). Apache-2.0.

const TTL_MS = 5 * 60 * 1000;
const MAX_MSG = 16384;
const CODE_RE = /^\/ws\/([ABCDEFGHJKMNPQRSTVWXYZ23456789]{8})$/;

export class Room {
  constructor(ctx) {
    this.ctx = ctx;
  }

  async fetch(request) {
    if (request.headers.get("Upgrade") !== "websocket") {
      return new Response("websocket only", { status: 426 });
    }
    if (this.ctx.getWebSockets().length >= 2) {
      return new Response("room full", { status: 409 });
    }
    const pair = new WebSocketPair();
    this.ctx.acceptWebSocket(pair[1]); // hibernation API: idle rooms cost ~nothing
    if ((await this.ctx.storage.getAlarm()) === null) {
      await this.ctx.storage.setAlarm(Date.now() + TTL_MS); // absolute TTL from first join
    }
    for (const peer of this.ctx.getWebSockets()) {
      if (peer !== pair[1]) peer.send('{"type":"peer-joined"}');
    }
    return new Response(null, { status: 101, webSocket: pair[0] });
  }

  webSocketMessage(ws, message) {
    if (typeof message !== "string" || message.length > MAX_MSG) {
      return ws.close(1009, "bad message");
    }
    for (const peer of this.ctx.getWebSockets()) {
      if (peer !== ws) peer.send(message);
    }
  }

  webSocketClose(ws) {
    for (const peer of this.ctx.getWebSockets()) {
      if (peer !== ws) peer.send('{"type":"peer-left"}');
    }
  }

  async alarm() {
    for (const ws of this.ctx.getWebSockets()) {
      ws.close(1000, "room expired");
    }
    await this.ctx.storage.deleteAll();
  }
}

export default {
  async fetch(request, env) {
    const match = new URL(request.url).pathname.match(CODE_RE);
    if (!match) return new Response("not found", { status: 404 });
    return env.ROOM.get(env.ROOM.idFromName(match[1])).fetch(request);
  }
};