const express = require('express');
const { WebSocketServer } = require('ws');
const { randomUUID } = require('crypto');
const path = require('path');

const app = express();
app.use(express.static(path.join(__dirname, 'public')));

const server = app.listen(3000, () => {
  console.log('Talkie running on http://localhost:3000');
});

const wss = new WebSocketServer({ server });

// roomId -> Set of { ws, id, name }
const rooms = new Map();

function getRoomMembers(roomId) {
  return rooms.get(roomId) ?? new Set();
}

function broadcast(roomId, data, excludeId = null) {
  const msg = JSON.stringify(data);
  getRoomMembers(roomId).forEach(client => {
    if (client.id !== excludeId && client.ws.readyState === 1) {
      client.ws.send(msg);
    }
  });
}

wss.on('connection', (ws) => {
  const clientId = randomUUID();
  let clientRoom = null;
  let clientName = 'Anonimo';

  ws.send(JSON.stringify({ type: 'id', id: clientId }));

  ws.on('message', (raw) => {
    let msg;
    try { msg = JSON.parse(raw); } catch { return; }

    if (msg.type === 'join') {
      clientRoom = msg.room.trim().toUpperCase();
      clientName = (msg.name || 'Anonimo').slice(0, 20);

      if (!rooms.has(clientRoom)) rooms.set(clientRoom, new Set());
      const room = rooms.get(clientRoom);

      // Tell new user about existing peers
      const peers = [...room].map(c => ({ id: c.id, name: c.name }));
      ws.send(JSON.stringify({ type: 'peers', peers }));

      // Tell existing peers about the new user
      broadcast(clientRoom, { type: 'peer-joined', id: clientId, name: clientName });

      room.add({ ws, id: clientId, name: clientName });
    }

    // WebRTC signaling: forward to specific peer
    if (['offer', 'answer', 'ice'].includes(msg.type)) {
      const room = getRoomMembers(clientRoom);
      const target = [...room].find(c => c.id === msg.to);
      if (target?.ws.readyState === 1) {
        target.ws.send(JSON.stringify({ ...msg, from: clientId }));
      }
    }

    // Talking state: broadcast to room
    if (msg.type === 'talking') {
      broadcast(clientRoom, { type: 'talking', id: clientId, name: clientName, active: msg.active }, clientId);
    }
  });

  ws.on('close', () => {
    if (!clientRoom) return;
    const room = getRoomMembers(clientRoom);
    room.forEach(c => { if (c.id === clientId) room.delete(c); });
    broadcast(clientRoom, { type: 'peer-left', id: clientId, name: clientName });
    if (room.size === 0) rooms.delete(clientRoom);
  });
});