// server.js
require('dotenv').config();
const express    = require('express');
const mysql      = require('mysql2/promise');
const bodyParser = require('body-parser');
const path       = require('path');
const axios      = require('axios');
const { uploadTrendsCsv } = require('./s3');

const app  = express();
const PORT = process.env.PORT || 3000;

// ─── Helpers ────────────────────────────────────────────────────────────────
// Fetch current New York time (with DST) via worldtimeapi.org
async function getNYTime() {
  try {
    const res = await axios.get('http://worldtimeapi.org/api/timezone/America/New_York');
    return new Date(res.data.datetime);  // ISO string with offset
  } catch (e) {
    console.error('Time API error:', e.message);
    return new Date(); // fallback to local clock
  }
}

// Format a JS Date into "YYYY-MM-DD HH:mm:ss" in NY time for SQL DATETIME
function localDatetimeSQL(date) {
  // datePart = "YYYY-MM-DD"
  const datePart = new Intl.DateTimeFormat('en-CA', {
    timeZone: 'America/New_York',
    year:     'numeric',
    month:    '2-digit',
    day:      '2-digit'
  }).format(date);
  // timePart = "HH:MM:SS"
  const timePart = new Intl.DateTimeFormat('en-GB', {
    timeZone: 'America/New_York',
    hour12:   false,
    hour:     '2-digit',
    minute:   '2-digit',
    second:   '2-digit'
  }).format(date);
  return `${datePart} ${timePart}`;
}

// Format a JS Date into "M/D/YY @HH:mm" (24-hour) for Slack
function shortEST(date) {
  const dateFmt = new Intl.DateTimeFormat('en-US', {
    timeZone: 'America/New_York',
    month:    'numeric',
    day:      'numeric',
    year:     '2-digit'
  });
  const timeFmt = new Intl.DateTimeFormat('en-US', {
    timeZone: 'America/New_York',
    hour12:   false,
    hour:     '2-digit',
    minute:   '2-digit'
  });
  return `${dateFmt.format(date)} @${timeFmt.format(date)}`;
}

// NOAA heat-index formula
function computeHeatIndex(T, R) {
  const [c1,c2,c3,c4,c5,c6,c7,c8,c9] = [
    -42.379, 2.04901523, 10.14333127, -0.22475541,
    -0.00683783, -0.05481717, 0.00122874, 0.00085282, -0.00000199
  ];
  const HI = c1 + c2*T + c3*R + c4*T*R
           + c5*T*T + c6*R*R + c7*T*T*R
           + c8*T*R*R + c9*T*T*R*R;
  return Math.round(HI * 100) / 100;
}

// Determine Day/Night shift and rolling period
function getShiftInfo(now) {
  const est = new Date(now.toLocaleString('en-US',{timeZone:'America/New_York'}));
  const h = est.getHours(), m = est.getMinutes();
  let shift, start = new Date(est);

  if (h > 7 || (h === 7 && m >= 0)) {
    if (h < 17 || (h === 17 && m < 30)) {
      shift = 'Day';   start.setHours(7,0,0,0);
    } else {
      shift = 'Night'; start.setHours(17,30,0,0);
    }
  } else {
    shift = 'Night';
    start.setDate(start.getDate() - 1);
    start.setHours(17,30,0,0);
  }

  const key = `${shift}-${start.toISOString().slice(0,10)}-${start.getHours()}${start.getMinutes()}`;
  return { shift, key, estNow: est };
}

// Fetch current weather for Baltimore
async function fetchCurrentWeather() {
  const key = process.env.WEATHER_API_KEY, zip = process.env.ZIP_CODE;
  if (!key || !zip) return 'Unavailable';
  try {
    const { data } = await axios.get(
      'https://api.openweathermap.org/data/2.5/weather',
      { params:{ zip:`${zip},us`, appid:key, units:'imperial' } }
    );
    const desc = data.weather[0].description.replace(/^\w/,c=>c.toUpperCase());
    const hi   = Math.round(data.main.temp_max);
    const hum  = data.main.humidity;
    return `${desc}. Hi of ${hi}, Humidity ${hum}%`;
  } catch (e) {
    console.error('Weather API error:', e.message);
    return 'Unavailable';
  }
}

// ─── MariaDB Pool & Table Setup ───────────────────────────────────────────────
const pool = mysql.createPool({
  host:            process.env.DB_HOST,
  port:            +process.env.DB_PORT||3306,
  user:            process.env.DB_USER,
  password:        process.env.DB_PASSWORD,
  database:        process.env.DB_NAME,
  waitForConnections:true,
  connectionLimit: 10,
  queueLimit:      0,
  connectTimeout:  10000,
  dateStrings:     ['DATETIME']
});

;(async()=>{
  await pool.execute(`
    CREATE TABLE IF NOT EXISTS readings (
      id INT AUTO_INCREMENT PRIMARY KEY,
      location VARCHAR(20) NOT NULL,
      stationDockDoor VARCHAR(10) NOT NULL,
      timestamp DATETIME NOT NULL,
      temperature DOUBLE, humidity DOUBLE, heatIndex DOUBLE
    ) CHARSET=utf8mb4;
  `);
})();

// ─── Middleware & Static ─────────────────────────────────────────────────────
app.use(bodyParser.json());
app.use(express.static(path.join(__dirname,'public'), { index:'heatmap.html' }));

// ─── SSE Setup ────────────────────────────────────────────────────────────────
let clients = [];
app.get('/api/stream',(req,res)=>{
  res.set({ 'Content-Type':'text/event-stream', 'Cache-Control':'no-cache', Connection:'keep-alive' });
  res.flushHeaders(); clients.push(res);
  req.on('close',()=> clients=clients.filter(c=>c!==res));
});
function broadcast(evt,data){
  const msg = `event: ${evt}\ndata: ${JSON.stringify(data)}\n\n`;
  clients.forEach(c=>c.write(msg));
}

// ─── Dual Dock-Door Endpoint ─────────────────────────────────────────────────
app.post('/api/readings', async (req,res)=>{
  try {
    const { inbound={}, outbound={} } = req.body;
    const { dockDoor: inD, temperature: inT, humidity: inH } = inbound;
    const { dockDoor: outD, temperature: outT, humidity: outH } = outbound;
    if ([inD,inT,inH,outD,outT,outH].some(v=>v==null))
      return res.status(400).json({ error:'Missing fields' });

    const hiIn  = computeHeatIndex(inT,inH);
    const hiOut = computeHeatIndex(outT,outH);
    const now   = await getNYTime();
    const { shift, key, estNow } = getShiftInfo(now);
    shiftCounters[key] = (shiftCounters[key]||0) +1;
    const period = shiftCounters[key];

    const sqlTs   = localDatetimeSQL(estNow);
    const shortTs = shortEST(estNow);

    await pool.execute(
      `INSERT INTO readings(location,stationDockDoor,timestamp,temperature,humidity,heatIndex)
       VALUES(?,?,?,?,?,?)`,
      ['Inbound',String(inD),sqlTs,inT,inH,hiIn]
    );
    await pool.execute(
      `INSERT INTO readings(location,stationDockDoor,timestamp,temperature,humidity,heatIndex)
       VALUES(?,?,?,?,?,?)`,
      ['Outbound',String(outD),sqlTs,outT,outH,hiOut]
    );

    broadcast('new-reading',{location:'Inbound',stationDockDoor:String(inD),timestamp:shortTs,temperature:inT,humidity:inH,heatIndex:hiIn});
    broadcast('new-reading',{location:'Outbound',stationDockDoor:String(outD),timestamp:shortTs,temperature:outT,humidity:outH,heatIndex:hiOut});

    // upload CSV
    const [rows] = await pool.execute(
      `SELECT * FROM readings WHERE DATE(timestamp)=CURDATE() ORDER BY timestamp`
    );
    let csvUrl=null;
    try{ csvUrl = await uploadTrendsCsv(
      shortTs.slice(6,8)+shortTs.slice(0,2)+shortTs.slice(3,5), rows
    ); }catch(_){}

    const weather = await fetchCurrentWeather();
    const text =
      `*_${shift} shift Period ${period} dock/trailer temperature checks for ${shortTs}_*\n`+
      `*_Current Weather Forecast for Baltimore: ${weather}_*\n\n`+
      `*_⬇️ Inbound Dock Door 🚛 :_* ${inD}\n`+
      `*_Temp:_* ${inT} °F 🌡️\n`+
      `*_Humidity:_* ${inH} % 💦\n`+
      `*_Heat Index:_* ${hiIn} °F 🥵\n\n`+
      `*_⬆️ Outbound Dock Door 🚛 :_* ${outD}\n`+
      `*_Temp:_* ${outT} °F 🌡️\n`+
      `*_Humidity:_* ${outH} % 💦\n`+
      `*_Heat Index:_* ${hiOut} °F 🥵`;

    await axios.post(
      process.env.SLACK_WEBHOOK_URL,
      { text },
      { headers:{ 'Content-Type':'application/json' } }
    );

    res.json({ success:true, shift, period, csvUrl });
  } catch (err) {
    console.error(err);
    res.status(500).json({ error: err.message });
  }
});

// ─── Area/Mod Endpoint ───────────────────────────────────────────────────────
app.post('/api/area-readings', async (req,res)=>{
  try {
    const { area, stationCode, temperature:T, humidity:H } = req.body;
    if (!area||!stationCode||T==null||H==null)
      return res.status(400).json({ error:'Missing fields' });

    const hi = computeHeatIndex(T,H);
    const now   = await getNYTime();
    const { shift, estNow } = getShiftInfo(now);

    const sqlTs   = localDatetimeSQL(estNow);
    const shortTs = shortEST(estNow);

    await pool.execute(
      `INSERT INTO readings(location,stationDockDoor,timestamp,temperature,humidity,heatIndex)
       VALUES(?,?,?,?,?,?)`,
      [area,stationCode,sqlTs,T,H,hi]
    );

    broadcast('new-area-reading',{location:area,stationDockDoor:stationCode,timestamp:shortTs,temperature:T,humidity:H,heatIndex:hi});

    const [rows] = await pool.execute(
      `SELECT * FROM readings WHERE DATE(timestamp)=CURDATE() ORDER BY timestamp`
    );
    let csvUrl=null;
    try{ csvUrl = await uploadTrendsCsv(
      shortTs.slice(6,8)+shortTs.slice(0,2)+shortTs.slice(3,5), rows
    ); }catch(_){}

    const weather = await fetchCurrentWeather();
    const text =
      `*_${shift} shift ${area} temp check for ${shortTs}_*\n`+
      `*_Current Weather Forecast for Baltimore: ${weather}_*\n\n`+
      `*_${area.toUpperCase()} station:_* ${stationCode}\n`+
      `*_Temp:_* ${T} °F 🌡️\n`+
      `*_Humidity:_* ${H} % 💦\n`+
      `*_Heat Index:_* ${hi} °F 🥵`;

    await axios.post(
      process.env.SLACK_WEBHOOK_URL,
      { text },
      { headers:{ 'Content-Type':'application/json' } }
    );

    res.json({ success:true, csvUrl });
  } catch(err) {
    console.error(err);
    res.status(500).json({ error: err.message });
  }
});

// ─── Fetch & Export ─────────────────────────────────────────────────────────
app.get('/api/readings', async (req,res)=>{
  const [rows] = await pool.execute(`SELECT * FROM readings ORDER BY timestamp`);
  res.json(rows);
});
app.get('/api/export', async (req,res)=>{
  const [rows] = await pool.execute(`SELECT * FROM readings ORDER BY timestamp`);
  res.setHeader('Content-disposition','attachment; filename=readings.csv');
  res.set('Content-Type','text/csv');
  res.write('id,location,stationDockDoor,timestamp,temperature,humidity,heatIndex\n');
  rows.forEach(r => {
    res.write(`${r.id},${r.location},${r.stationDockDoor},${r.timestamp},${r.temperature},${r.humidity},${r.heatIndex}\n`);
  });
  res.end();
});

// ─── Start ───────────────────────────────────────────────────────────────────
app.listen(PORT, ()=>console.log(`Server running http://localhost:${PORT}`));