import { state } from './state.js';

let ws;
let reconnectAttempts = 0;
let reconnectTimer = null;
const outbox = [];
let sessionId = localStorage.getItem('sessionId') || null;
let lastRoomId = localStorage.getItem('lastRoomId') || null;

export function wsIsOpen() { return ws && ws.readyState === WebSocket.OPEN; }
export function sendMsg(obj) { if (wsIsOpen()) ws.send(JSON.stringify(obj)); else outbox.push(obj); }

function scheduleReconnect(connect) {
  if (reconnectTimer) return;
  const delay = Math.min(30000, 1000 * Math.pow(2, reconnectAttempts));
  reconnectAttempts++;
  reconnectTimer = setTimeout(() => { reconnectTimer = null; connect(); }, delay);
}

export function connectWS(onMessage) {
  const url = (location.protocol === 'https:' ? 'wss://' : 'ws://') + location.host;
  ws = new WebSocket(url);
  ws.addEventListener('open', () => {
    reconnectAttempts = 0;
    // Try to resume session immediately on (re)connect
    if (sessionId) {
      try { ws.send(JSON.stringify({ type: 'resume', sessionId })); } catch {}
    }
    setTimeout(() => { while (outbox.length && wsIsOpen()) { try { ws.send(JSON.stringify(outbox.shift())); } catch { break; } } }, 100);
  });
  ws.addEventListener('message', (ev) => onMessage(ev));
  ws.addEventListener('close', () => { scheduleReconnect(() => connectWS(onMessage)); });
  ws.addEventListener('error', () => { try { ws.close(); } catch {} });
}

window.addEventListener('online', () => {
  if (!wsIsOpen()) {
    if (reconnectTimer) { clearTimeout(reconnectTimer); reconnectTimer = null; }
    // Kick off a reconnect by calling connectWS from app main again
  }
});

// Helpers to update cached ids from other modules
export function cacheSessionId(id) {
  if (!id) return;
  sessionId = id;
  try { localStorage.setItem('sessionId', id); } catch {}
}
export function cacheLastRoomId(id) {
  if (!id) return;
  lastRoomId = id;
  try { localStorage.setItem('lastRoomId', id); } catch {}
}