const express = require('express');
const cron = require('node-cron');
const fs = require('fs');
const http = require('http');
const https = require('https');
const path = require('path');

const app = express();
app.use(express.json({ limit: '1mb' }));

const DATA_FILE = process.env.DATA_FILE || '/data/trips.json';
const GATEWAY_URL = process.env.GATEWAY_URL || 'http://whatsapp-gateway.ai-agents.svc.cluster.local:5001/send-message';
const OLLAMA_URL = process.env.OLLAMA_URL || 'http://ollama.ai-agents.svc.cluster.local:11434/api/generate';
const PERSONAL_NUM = process.env.PERSONAL_NUM || '+14085505485';
const GROUP_URL = process.env.GROUP_URL || 'https://chat.whatsapp.com/0Txfg7iZBbvIuvTbTqqgAX';
const PORT = parseInt(process.env.PORT) || 6002;

// ── Persistence ──────────────────────────────────────────────────────────────
function loadTrips() {
  try { return JSON.parse(fs.readFileSync(DATA_FILE, 'utf8')); }
  catch { return []; }
}

function saveTrips(trips) {
  fs.mkdirSync(path.dirname(DATA_FILE), { recursive: true });
  fs.writeFileSync(DATA_FILE, JSON.stringify(trips, null, 2));
}

// ── HTTP Helpers ─────────────────────────────────────────────────────────────
function fetchJson(url) {
  return new Promise((resolve, reject) => {
    const lib = url.startsWith('https') ? https : http;
    lib.get(url, { headers: { 'User-Agent': 'AgenticOS-TripService/1.0' } }, (res) => {
      let data = '';
      res.on('data', chunk => data += chunk);
      res.on('end', () => {
        try { resolve(JSON.parse(data)); } catch (e) { reject(e); }
      });
    }).on('error', reject);
  });
}

function fetchText(url) {
  return new Promise((resolve, reject) => {
    const lib = url.startsWith('https') ? https : http;
    lib.get(url, { headers: { 'User-Agent': 'AgenticOS-TripService/1.0' } }, (res) => {
      let data = '';
      res.on('data', chunk => data += chunk);
      res.on('end', () => resolve(data));
    }).on('error', reject);
  });
}

// ── Integrations ─────────────────────────────────────────────────────────────
async function getWeather(location) {
  try {
    const data = await fetchJson(`https://wttr.in/${encodeURIComponent(location)}?format=j1`);
    const curr = data.current_condition[0];
    return `${curr.temp_F}°F, ${curr.weatherDesc[0].value}`;
  } catch (e) {
    return 'Weather unavailable';
  }
}

async function getNpsAlerts(parkCode) {
  if (!parkCode) return null;
  try {
    const data = await fetchJson(`https://developer.nps.gov/api/v1/alerts?parkCode=${parkCode}&api_key=DEMO_KEY`);
    if (data.data && data.data.length > 0) {
      return data.data.map(a => `⚠️ ${a.title}`).slice(0, 3).join('\n');
    }
    return 'No active NPS alerts.';
  } catch (e) {
    return 'NPS alerts unavailable';
  }
}

async function getTdotTraffic() {
  try {
    // Basic TDOT Incidents fetch (Smoky Mountains general area filter could be applied, returning raw count for brevity)
    const data = await fetchJson('https://smartway.tn.gov/Traffic/Api/Incidents');
    if (data && data.length >= 0) {
      return `Current active incidents in TN: ${data.length}`;
    }
    return 'No traffic data.';
  } catch (e) {
    return 'Traffic data unavailable';
  }
}

async function getAiInsight(activityDetails, location) {
  return new Promise((resolve) => {
    const prompt = `Provide one short, clever tip or insight for someone visiting ${location} today, doing: ${activityDetails}. Keep it under 2 sentences.`;
    const body = JSON.stringify({ model: 'qwen2.5:0.5b', prompt, stream: false });
    const url = new URL(OLLAMA_URL);
    const req = http.request({
      hostname: url.hostname, port: url.port, path: url.pathname, method: 'POST',
      headers: { 'Content-Type': 'application/json', 'Content-Length': Buffer.byteLength(body) }
    }, (res) => {
      let d = '';
      res.on('data', c => d += c);
      res.on('end', () => {
        try { resolve(JSON.parse(d).response.trim()); } catch { resolve('Have a great trip!'); }
      });
    });
    req.on('error', () => resolve('Have a great trip!'));
    req.write(body);
    req.end();
  });
}

function sendWhatsApp(to, message) {
  return new Promise((resolve) => {
    const body = JSON.stringify({ to, message });
    const url = new URL(GATEWAY_URL);
    const req = http.request({
      hostname: url.hostname, port: url.port, path: url.pathname, method: 'POST',
      headers: { 'Content-Type': 'application/json', 'Content-Length': Buffer.byteLength(body) }
    }, (res) => {
      res.on('data', () => {});
      res.on('end', () => resolve(true));
    });
    req.on('error', () => resolve(false));
    req.write(body);
    req.end();
  });
}

// ── Briefing Generation ──────────────────────────────────────────────────────
async function generateAndSendBriefing(trip, dayPlan) {
  const weather = await getWeather(dayPlan.location || 'Pigeon Forge, TN');
  const nps = await getNpsAlerts(trip.npsParkCode);
  const traffic = await getTdotTraffic();
  const insight = await getAiInsight(dayPlan.activities, dayPlan.location || 'Smoky Mountains');

  const message = `*🏕️ ${trip.name} - ${dayPlan.date} Briefing*\n\n` +
    `*🌤️ Weather (${dayPlan.location || 'Pigeon Forge'}):* ${weather}\n\n` +
    `*📋 Today's Plan:*\n${dayPlan.activities}\n\n` +
    `*🍴 Meals:*\n${dayPlan.meals}\n\n` +
    (nps ? `*🌲 Park Alerts:*\n${nps}\n\n` : '') +
    `*🚗 Traffic Info:*\n${traffic}\n\n` +
    `*🤖 AI Insight:*\n${insight}`;

  console.log(`[TripService] Sending briefing for ${trip.name} - ${dayPlan.date}`);
  await sendWhatsApp(PERSONAL_NUM, message);
  
  // Support specific groups for this trip, fallback to default if configured
  let groupsToNotify = [];
  if (trip.groupUrls && Array.isArray(trip.groupUrls) && trip.groupUrls.length > 0) {
    groupsToNotify = trip.groupUrls;
  } else if (trip.sendToGroup && GROUP_URL) {
    groupsToNotify = [GROUP_URL];
  }
  
  for (const group of groupsToNotify) {
    await sendWhatsApp(group, message);
  }
}

// ── Routes ───────────────────────────────────────────────────────────────────
app.post('/trips', (req, res) => {
  const trip = req.body;
  if (!trip.name || !trip.days) return res.status(400).json({ error: 'Missing name or days' });
  
  trip.id = `trip_${Date.now()}`;
  const trips = loadTrips();
  trips.push(trip);
  saveTrips(trips);
  
  res.json({ success: true, id: trip.id });
});

app.get('/trips', (req, res) => {
  res.json(loadTrips());
});

app.post('/trips/:id/test', async (req, res) => {
  const trips = loadTrips();
  const trip = trips.find(t => t.id === req.params.id);
  if (!trip) return res.status(404).json({ error: 'Trip not found' });
  
  // Just use the first day's plan for the test
  const dayPlan = trip.days[0];
  try {
    await generateAndSendBriefing(trip, dayPlan);
    res.json({ success: true, message: 'Test briefing sent!' });
  } catch (err) {
    res.status(500).json({ error: err.message });
  }
});

app.get('/health', (req, res) => res.json({ status: 'ok' }));

// ── Scheduler (Runs every minute, checks if time to send) ────────────────────
cron.schedule('* * * * *', async () => {
  const now = new Date();
  const trips = loadTrips();
  
  // Format current date as YYYY-MM-DD
  const tzOffset = -4 * 60; // Assuming EDT for now, ideally use a robust timezone approach
  const localTime = new Date(now.getTime() + tzOffset * 60000);
  const todayStr = localTime.toISOString().split('T')[0];
  const currentHour = localTime.getUTCHours().toString().padStart(2, '0');
  const currentMin = localTime.getUTCMinutes().toString().padStart(2, '0');
  const currentTime = `${currentHour}:${currentMin}`;

  for (const trip of trips) {
    const briefingTime = trip.briefingTime || '07:00';
    if (currentTime !== briefingTime) continue; // Only trigger at exact minute

    const dayPlan = trip.days.find(d => d.date === todayStr);
    if (!dayPlan) continue;

    // To prevent duplicate sends if cron runs multiple times in the same minute
    if (dayPlan.sent) continue;

    try {
      await generateAndSendBriefing(trip, dayPlan);
      dayPlan.sent = true;
      saveTrips(trips);
    } catch (err) {
      console.error(`[TripService] Failed to send briefing: ${err.message}`);
    }
  }
});

app.listen(PORT, () => {
  console.log(`[TripService] Listening on :${PORT}`);
});