import nodemailer from 'nodemailer';

const env = process.env;

// ---- Telegram ----
async function sendTelegram(text) {
  const token = env.TELEGRAM_BOT_TOKEN;
  const chats = (env.TELEGRAM_CHAT_IDS || '').split(',').map(s => s.trim()).filter(Boolean);
  if (!token || chats.length === 0) return null;

  const results = [];
  for (const chatId of chats) {
    try {
      const r = await fetch(`https://api.telegram.org/bot${token}/sendMessage`, {
        method: 'POST',
        headers: { 'Content-Type': 'application/json' },
        body: JSON.stringify({ chat_id: chatId, text, parse_mode: 'HTML', disable_notification: false })
      });
      if (!r.ok) throw new Error(`HTTP ${r.status}: ${await r.text()}`);
      results.push({ chat: chatId, ok: true });
    } catch (e) {
      results.push({ chat: chatId, ok: false, error: e.message });
    }
  }
  return results;
}

// ---- ntfy.sh push ----
async function sendNtfy(text, title, priority) {
  const topic = env.NTFY_TOPIC;
  if (!topic) return null;
  const server = env.NTFY_SERVER || 'https://ntfy.sh';
  try {
    const r = await fetch(`${server}/${topic}`, {
      method: 'POST',
      headers: {
        'Title': title || 'Alerta Shivao',
        'Priority': priority || 'urgent',
        'Tags': 'rotating_light,anchor,warning',
        'Click': text.match(/https:\/\/maps[^\s]+/)?.[0] || ''
      },
      body: text
    });
    if (!r.ok) throw new Error(`HTTP ${r.status}`);
    return { ok: true };
  } catch (e) {
    return { ok: false, error: e.message };
  }
}

// ---- Email ----
let transporter = null;
function getEmailTransporter() {
  if (transporter) return transporter;
  if (!env.SMTP_HOST || !env.SMTP_USER) return null;
  transporter = nodemailer.createTransport({
    host: env.SMTP_HOST,
    port: parseInt(env.SMTP_PORT || '587'),
    secure: env.SMTP_SECURE === 'true',
    auth: { user: env.SMTP_USER, pass: env.SMTP_PASS }
  });
  return transporter;
}

async function sendEmail(text, subject) {
  const t = getEmailTransporter();
  const recipients = (env.SMTP_TO || '').split(',').map(s => s.trim()).filter(Boolean);
  if (!t || recipients.length === 0) return null;
  try {
    await t.sendMail({
      from: env.SMTP_FROM || env.SMTP_USER,
      to: recipients.join(','),
      subject: subject || 'Alerta Shivao',
      text,
      html: `<pre style="font-family:system-ui;font-size:14px">${text.replace(/</g, '&lt;')}</pre>`
    });
    return { ok: true, recipients: recipients.length };
  } catch (e) {
    return { ok: false, error: e.message };
  }
}

// ---- Twilio SMS / WhatsApp ----
async function twilioRequest(messages) {
  const sid = env.TWILIO_ACCOUNT_SID;
  const token = env.TWILIO_AUTH_TOKEN;
  if (!sid || !token) return null;
  const auth = 'Basic ' + Buffer.from(`${sid}:${token}`).toString('base64');
  const url = `https://api.twilio.com/2010-04-01/Accounts/${sid}/Messages.json`;
  const results = [];
  for (const msg of messages) {
    try {
      const body = new URLSearchParams({ From: msg.from, To: msg.to, Body: msg.body });
      const r = await fetch(url, { method: 'POST', headers: { 'Authorization': auth, 'Content-Type': 'application/x-www-form-urlencoded' }, body });
      if (!r.ok) throw new Error(`HTTP ${r.status}: ${await r.text()}`);
      results.push({ to: msg.to, ok: true });
    } catch (e) {
      results.push({ to: msg.to, ok: false, error: e.message });
    }
  }
  return results;
}

async function sendSMS(text) {
  const from = env.TWILIO_FROM_NUMBER;
  const tos = (env.TWILIO_SMS_TO || '').split(',').map(s => s.trim()).filter(Boolean);
  if (!from || tos.length === 0) return null;
  const messages = tos.map(to => ({ from, to, body: text }));
  return twilioRequest(messages);
}

async function sendWhatsApp(text) {
  const from = env.TWILIO_WHATSAPP_FROM;
  const tos = (env.TWILIO_WHATSAPP_TO || '').split(',').map(s => s.trim()).filter(Boolean);
  if (!from || tos.length === 0) return null;
  const messages = tos.map(to => ({
    from: from.startsWith('whatsapp:') ? from : `whatsapp:${from}`,
    to: to.startsWith('whatsapp:') ? to : `whatsapp:${to}`,
    body: text
  }));
  return twilioRequest(messages);
}

// ---- Generic webhook ----
async function sendWebhook(payload) {
  const url = env.WEBHOOK_URL;
  if (!url) return null;
  try {
    const r = await fetch(url, {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(payload)
    });
    if (!r.ok) throw new Error(`HTTP ${r.status}`);
    return { ok: true };
  } catch (e) {
    return { ok: false, error: e.message };
  }
}

// ---- Build message ----
export function buildAlarmMessage(p) {
  const lat = p.lat?.toFixed(6) ?? '?';
  const lng = p.lng?.toFixed(6) ?? '?';
  const mapsUrl = (p.lat && p.lng) ? `https://maps.google.com/?q=${lat},${lng}` : '';
  const dist = Math.round(p.distance || 0);
  const time = new Date(p.ts || Date.now()).toLocaleString('pt-BR', { timeZone: 'America/Sao_Paulo' });
  const boat = p.boat || 'Veleiro';
  const reason = p.reason === 'heartbeat_lost' ?
    'Servidor perdeu contato com o celular do barco' :
    `Saiu ${dist}m da posição de fundeio (raio ${p.radius || '?'}m)`;

  return `🚨 ALERTA — ${boat}

${reason}.

📍 Posição: ${lat}, ${lng}
${mapsUrl ? `🗺️ ${mapsUrl}\n` : ''}🕐 ${time}

Esta é uma mensagem automática do sistema de vigia de fundeio.`;
}

// ---- Main dispatcher ----
export async function dispatchAlarm(payload) {
  const text = buildAlarmMessage(payload);
  const subject = `🚨 ${payload.boat || 'Veleiro'} — ALERTA de fundeio`;

  const tasks = [
    ['telegram', sendTelegram(text)],
    ['ntfy', sendNtfy(text, subject, 'urgent')],
    ['email', sendEmail(text, subject)],
    ['sms', sendSMS(text)],
    ['whatsapp', sendWhatsApp(text)],
    ['webhook', sendWebhook({ ...payload, message: text })]
  ];

  const sent = [];
  const failed = [];

  for (const [name, promise] of tasks) {
    const result = await promise;
    if (result === null) continue; // not configured
    if (Array.isArray(result)) {
      for (const r of result) {
        if (r.ok) sent.push(name);
        else failed.push({ channel: name, ...r });
      }
    } else {
      if (result.ok) sent.push(name);
      else failed.push({ channel: name, ...result });
    }
  }
  return { sent, failed };
}

// Quick test ping (no urgency)
export async function dispatchTest() {
  const text = `✅ Teste — Sistema Shivao Cloud operacional.\nHora: ${new Date().toLocaleString('pt-BR')}`;
  const sent = [];
  const failed = [];
  const r1 = await sendTelegram(text);
  if (r1) r1.forEach(r => r.ok ? sent.push('telegram') : failed.push({ channel: 'telegram', ...r }));
  const r2 = await sendNtfy(text, 'Teste Shivao', 'default');
  if (r2) r2.ok ? sent.push('ntfy') : failed.push({ channel: 'ntfy', ...r2 });
  const r3 = await sendEmail(text, 'Teste Shivao');
  if (r3) r3.ok ? sent.push('email') : failed.push({ channel: 'email', ...r3 });
  return { sent, failed };
}

export function listConfiguredChannels() {
  const channels = [];
  if (env.TELEGRAM_BOT_TOKEN && env.TELEGRAM_CHAT_IDS) channels.push('telegram');
  if (env.NTFY_TOPIC) channels.push('ntfy');
  if (env.SMTP_HOST && env.SMTP_TO) channels.push('email');
  if (env.TWILIO_ACCOUNT_SID && env.TWILIO_SMS_TO) channels.push('sms');
  if (env.TWILIO_ACCOUNT_SID && env.TWILIO_WHATSAPP_TO) channels.push('whatsapp');
  if (env.WEBHOOK_URL) channels.push('webhook');
  return channels;
}