const { Client, LocalAuth } = require('whatsapp-web.js');
const qrcode = require('qrcode');
const qrcodeTerminal = require('qrcode-terminal');
const fs = require('fs');
const path = require('path');
const config = require('./config');
const { sendSMS } = require('./sms');
const { sendTelegramPhoto } = require('./telegram');

let messageQueue = [];
let flushTimer = null;
let flushTimerStart = null;
let client = null;
let restartDelay = 1000;
let starting = false;
let restarting = false;
let msgCounter = 0;

let startTime = Date.now();
let totalForwarded = 0;
let userStats = {};
let groupStats = {};

function ts() {
  return new Date().toLocaleString('he-IL', { hour12: false });
}

function log(level, msg) {
  console.log(`[${ts()}] [${level}] ${msg}`);
}

function flushTime() {
  if (!flushTimerStart) return '--:--';
  const t = new Date(Date.now() + Math.max(0, config.batch.intervalMs - (Date.now() - flushTimerStart)));
  return t.toLocaleTimeString('he-IL', { hour: '2-digit', minute: '2-digit', second: '2-digit', hour12: false });
}

function formatBatch(queue) {
  const groups = {};
  for (const m of queue) {
    if (!groups[m.group]) groups[m.group] = [];
    groups[m.group].push(m);
  }

  const parts = [];
  for (const [group, msgs] of Object.entries(groups)) {
    parts.push(`[👥 ${group} 👥]`);
    for (const m of msgs) {
      parts.push(`${m.sender}: ${m.text}`);
    }
  }
  return parts.join('\n');
}

function queueSize() {
  return messageQueue.reduce(
      (sum, m) => sum + m.group.length + m.sender.length + m.text.length + 6,
      0
  );
}

function scheduleFlush() {
  if (flushTimer) clearTimeout(flushTimer);
  if (!flushTimerStart) flushTimerStart = Date.now();
  flushTimer = setTimeout(flushQueue, config.batch.intervalMs);
}

async function flushQueue() {
  if (restarting) return;
  if (messageQueue.length === 0) return;

  flushTimer = null;
  flushTimerStart = null;

  const batch = messageQueue;
  messageQueue = [];
  msgCounter = 0;

  const text = formatBatch(batch);

  try {
    await sendSMS(text);
    log('INFO', `Flushed ${batch.length} messages`);
    for (const m of batch) {
      userStats[m.sender] = (userStats[m.sender] || 0) + 1;
      groupStats[m.group] = (groupStats[m.group] || 0) + 1;
      totalForwarded++;
    }
  } catch (err) {
    log('ERROR', `Flush failed: ${err.message}`);
    messageQueue = batch.concat(messageQueue);
    msgCounter = messageQueue.length;
    scheduleFlush();
  }
}

function enqueue(group, sender, text) {
  msgCounter++;
  messageQueue.push({ group, sender, text });

  scheduleFlush();
  log('QUEUE', `Queue #${msgCounter} - Message from ${sender}, flushed at ${flushTime()}`);

  if (queueSize() >= config.batch.maxChars) {
    clearTimeout(flushTimer);
    flushTimer = null;
    flushTimerStart = null;
    flushQueue();
  }
}

async function killClient() {
  if (!client) return;

  try {
    client.removeAllListeners();
  } catch {}

  try {
    await client.destroy();
  } catch {}

  /**
   * IMPORTANT:
   * Give Chromium time to release Windows file locks
   */
  await new Promise(r => setTimeout(r, 3000));

  client = null;
}

let keepAliveTimer = null;

function startKeepAlive() {
  if (keepAliveTimer) clearInterval(keepAliveTimer);
  const ka = config.keepAlive;
  if (!ka || !ka.url) return;

  log('INIT', `Keep-alive ping every ${ka.intervalMs / 1000}s to ${ka.url}`);
  const ping = () => {
    fetch(ka.url).catch(() => {});
  };
  ping();
  keepAliveTimer = setInterval(ping, ka.intervalMs);
}

async function startClient() {
  if (starting) {
    log('WARN', 'Already starting — skipping duplicate call');
    return;
  }

  starting = true;

  try {
    restarting = true;

    log('INIT', 'Starting OmegaBaSMS...');
    await killClient();

    log('INIT', `Groups to monitor: ${config.groupNames.join(', ')}`);
    log('INIT', `Batch interval: ${config.batch.intervalMs / 1000}s / max ${config.batch.maxChars} chars`);
    log('INIT', `Forwarding SMS to: ${config.smsGateway.recipientNumber}`);

    if (config.telegram.botToken) {
      log('INIT', 'Telegram notifications enabled');
    }

    // startKeepAlive();

    log('INIT', 'Launching WhatsApp Web...');

    client = new Client({
      authStrategy: new LocalAuth(),
      puppeteer: {
        headless: true,
        args: ['--no-sandbox', '--disable-setuid-sandbox']
      }
    });

    client.on('qr', async (qr) => {
      log('QR', 'New QR code received — scan with WhatsApp on your phone');
      qrcodeTerminal.generate(qr, { small: true });

      if (config.telegram.botToken) {
        try {
          const buf = await qrcode.toBuffer(qr, { width: 400 });
          await sendTelegramPhoto(buf, 'WhatsApp re-auth needed - scan this QR\nhttps://wa.me/settings/linked_devices');
          log('QR', 'QR photo sent to Telegram');
        } catch (err) {
          log('ERROR', `Failed to send QR photo: ${err.message}`);
        }
      }
    });

    client.on('ready', () => {
      restarting = false;
      restartDelay = 1000;
      log('READY', 'WhatsApp connected successfully');
      log('READY', `Monitoring ${config.groupNames.length} group(s): ${config.groupNames.join(', ')}`);
      log('READY', `Forwarding to ${config.smsGateway.recipientNumber}`);
    });

    client.on('auth_failure', (msg) => {
      log('ERROR', `Auth failure: ${msg}`);
    });

    client.on('disconnected', async (reason) => {
      if (starting) return;

      log('WARN', `Disconnected: ${reason}. Restarting in ${restartDelay / 1000}s...`);

      restarting = true;

      if (reason === 'LOGOUT') {
        const authDir = path.join(__dirname, '.wwebjs_auth');
        if (fs.existsSync(authDir)) {
          try {
            fs.rmSync(authDir, {
              recursive: true,
              force: true,
              maxRetries: 10,
              retryDelay: 500
            });

            log('WARN', 'Cleared old session data');
          } catch (err) {
            log('ERROR', `Failed clearing auth data: ${err.message}`);
          }
        }
      }

      await new Promise((r) => setTimeout(r, restartDelay));
      restartDelay = Math.min(restartDelay * 2, 30000);
      startClient();
    });

    client.on('message_create', async (message) => {
      try {
        if (restarting) return;
        if (message.type !== 'chat') return;

        const chat = await message.getChat();
        if (!chat.isGroup) return;
        if (!config.groupNames.includes(chat.name)) return;
        if (message.fromMe && !config.includeOwnMessages) return;

        const contact = await message.getContact();
        const sender = message.fromMe
            ? config.ownName
            : (contact.name || contact.pushname || contact.shortName || contact.number || 'Unknown');

        const body = message.body || (message.hasMedia ? '[Media]' : '');
        if (!body) return;

        enqueue(chat.name, sender, body);
      } catch (err) {
        log('ERROR', `Message handler: ${err.message}`);
      }
    });

    client.initialize();

  } finally {
    starting = false;
  }
}

const http = require('http');
function renderDashboard() {
  const uptime = Math.floor((Date.now() - startTime) / 1000);
  const h = Math.floor(uptime / 3600);
  const m = Math.floor((uptime % 3600) / 60);
  const s = uptime % 60;
  const uptimeStr = `${h}h ${m}m ${s}s`;

  const userRows = Object.entries(userStats)
    .sort((a, b) => b[1] - a[1])
    .map(([name, count]) =>
      `<tr><td>${name}</td><td>${count}</td></tr>`
    ).join('');

  const groupRows = Object.entries(groupStats)
    .sort((a, b) => b[1] - a[1])
    .map(([name, count]) =>
      `<tr><td>${name}</td><td>${count}</td></tr>`
    ).join('');

  const connected = client && !restarting;

  const api = JSON.stringify({
    uptime, uptimeStr, connected,
    totalForwarded, queued: messageQueue.length, flushTime: flushTime(),
    userStats, groupStats,
  });

  return `<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>OmegaBaSMS</title>
<style>
  * { margin: 0; padding: 0; box-sizing: border-box; }
  body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: #0f172a; color: #e2e8f0; min-height: 100vh; padding: 2rem;
  }
  h1 {
    font-size: 1.75rem; font-weight: 700; margin-bottom: 0.25rem;
    background: linear-gradient(135deg, #22d3ee, #3b82f6);
    -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  }
  .subtitle { color: #64748b; margin-bottom: 2rem; font-size: 0.9rem; }
  .grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(220px, 1fr)); gap: 1rem; margin-bottom: 2rem; }
  .card {
    background: #1e293b; border-radius: 12px; padding: 1.25rem; border: 1px solid #334155;
  }
  .card .label { font-size: 0.75rem; text-transform: uppercase; letter-spacing: 0.05em; color: #64748b; margin-bottom: 0.5rem; }
  .card .value { font-size: 1.75rem; font-weight: 700; }
  .card .value.green { color: #22c55e; }
  .card .value.blue { color: #3b82f6; }
  .card .value.yellow { color: #eab308; }
  .card .value.red { color: #ef4444; }
  .status-dot {
    display: inline-block; width: 10px; height: 10px; border-radius: 50%;
    margin-right: 0.5rem;
  }
  .status-dot.on { background: #22c55e; box-shadow: 0 0 8px #22c55e88; }
  .status-dot.off { background: #ef4444; box-shadow: 0 0 8px #ef444488; }
  .tables { display: grid; grid-template-columns: 1fr 1fr; gap: 1.5rem; }
  @media (max-width: 640px) { .tables { grid-template-columns: 1fr; } }
  h2 { font-size: 1rem; font-weight: 600; margin-bottom: 0.75rem; color: #94a3b8; }
  table { width: 100%; border-collapse: collapse; }
  th { text-align: left; font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.05em; color: #64748b; padding: 0.5rem 0.75rem; border-bottom: 1px solid #334155; }
  td { padding: 0.5rem 0.75rem; border-bottom: 1px solid #1e293b; font-size: 0.9rem; }
  tr:last-child td { border-bottom: none; }
  td:last-child { text-align: right; font-weight: 600; }
  .bar-bg { background: #334155; border-radius: 4px; height: 6px; overflow: hidden; margin-top: 4px; }
  .bar-fill { height: 100%; border-radius: 4px; background: linear-gradient(90deg, #3b82f6, #22d3ee); }
</style>
</head>
<body>
  <div id="app">
    <h1>OmegaBaSMS</h1>
    <p class="subtitle">WhatsApp group messages forwarded via SMS</p>
    <div class="grid">
      <div class="card"><div class="label">Status</div><div class="value" id="status">—</div></div>
      <div class="card"><div class="label">Uptime</div><div class="value blue" id="uptime">—</div></div>
      <div class="card"><div class="label">Forwarded</div><div class="value green" id="forwarded">—</div></div>
      <div class="card"><div class="label">Queued</div><div class="value yellow" id="queued">—</div><div style="font-size:0.75rem;color:#64748b;margin-top:0.25rem" id="flushTime"></div></div>
    </div>
    <div class="tables">
      <div><h2>By Sender</h2><table><thead><tr><th>Name</th><th>Messages</th></tr></thead><tbody id="users"></tbody></table></div>
      <div><h2>By Group</h2><table><thead><tr><th>Group</th><th>Messages</th></tr></thead><tbody id="groups"></tbody></table></div>
    </div>
  </div>
<script>
async function poll() {
  try {
    const r = await fetch('/api/stats');
    const d = await r.json();
    document.getElementById('status').innerHTML = '<span class="status-dot ' + (d.connected ? 'on' : 'off') + '"></span>' + (d.connected ? 'Connected' : 'Disconnected');
    document.getElementById('uptime').textContent = d.uptimeStr;
    document.getElementById('forwarded').textContent = d.totalForwarded;
    document.getElementById('queued').textContent = d.queued;
    document.getElementById('flushTime').textContent = d.queued > 0 ? 'flushed at ' + d.flushTime : '';
    document.getElementById('users').innerHTML = Object.entries(d.userStats).sort((a,b) => b[1]-a[1]).map(([n,c]) => '<tr><td>' + n + '</td><td>' + c + '</td></tr>').join('') || '<tr><td colspan="2" style="color:#64748b;">No messages yet</td></tr>';
    document.getElementById('groups').innerHTML = Object.entries(d.groupStats).sort((a,b) => b[1]-a[1]).map(([n,c]) => '<tr><td>' + n + '</td><td>' + c + '</td></tr>').join('') || '<tr><td colspan="2" style="color:#64748b;">No messages yet</td></tr>';
  } catch(e) {}
}
setInterval(poll, 3000);
poll();
</script>
</body>
</html>`;
}

const server = http.createServer((req, res) => {
  if (req.url === '/liveness') {
    res.writeHead(200, { 'Content-Type': 'text/plain' });
    res.end('OK');
    return;
  }
  if (req.url === '/api/stats') {
    res.writeHead(200, { 'Content-Type': 'application/json' });
    res.end(JSON.stringify({
      uptime: Math.floor((Date.now() - startTime) / 1000),
      uptimeStr: (() => {
        const t = Math.floor((Date.now() - startTime) / 1000);
        return Math.floor(t/3600)+'h '+Math.floor((t%3600)/60)+'m '+t%60+'s';
      })(),
      connected: !!(client && !restarting),
      totalForwarded,
      queued: messageQueue.length,
      flushTime: flushTime(),
      userStats,
      groupStats,
    }));
    return;
  }
  res.writeHead(200, { 'Content-Type': 'text/html; charset=utf-8' });
  res.end(renderDashboard());
});
const PORT = process.env.PORT || 3000;
server.listen(PORT, () => log('INIT', `Dashboard on http://0.0.0.0:${PORT}`));

/** Recoverable error detection */
function shouldRestart(err) {
  const msg = (err && err.message) || String(err);
   return msg.includes('detached') ||
      msg.includes('Execution context was destroyed') ||
      msg.includes('Target closed') ||
      msg.includes('Session closed') ||
      msg.includes('Navigation failed') ||
      msg.includes('Protocol error');
}

process.on('uncaughtException', (err) => {
  if (shouldRestart(err)) {
    log('WARN', `Recoverable: ${err.message}. Restarting...`);
    startClient();
    return;
  }

  log('FATAL', err.message);
  process.exit(1);
});

process.on('unhandledRejection', (err) => {
  if (shouldRestart(err)) {
    log('WARN', `Recoverable: ${err.message}. Restarting...`);
    startClient();
    return;
  }

  log('FATAL', `Unhandled rejection: ${err.message}`);
  process.exit(1);
});

startClient();