// 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;

// In-memory shift counters
const shiftCounters = {};

// Helpers
const pad2 = n => n.toString().padStart(2, '0');

function shortEST(d) {
  const est = new Date(d.toLocaleString('en-US', { timeZone: 'America/New_York' }));
  const M = est.getMonth() + 1, D = est.getDate(), YY = String(est.getFullYear()).slice(-2);
  const hh = pad2(est.getHours()), mm = pad2(est.getMinutes());
  return `${M}/${D}/${YY} @${hh}:${mm}`;
}

function formatDateEST(d) {
  const est = new Date(d.toLocaleString('en-US', { timeZone: 'America/New_York' }));
  const y = est.getFullYear(), M = pad2(est.getMonth()+1), D = pad2(est.getDate());
  const hh = pad2(est.getHours()), mm = pad2(est.getMinutes()), ss = pad2(est.getSeconds());
  return `${y}-${M}-${D} ${hh}:${mm}:${ss}`;
}

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;
}

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, start, key, estNow: est };
}

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
const pool = mysql.createPool({
  host:               process.env.DB_HOST,
  port:               parseInt(process.env.DB_PORT,10)||3306,
  user:               process.env.DB_USER,
  password:           process.env.DB_PASSWORD,
  database:           process.env.DB_NAME,
  waitForConnections: true,
  connectionLimit:    10,
  queueLimit:         0,
  connectTimeout:     10000
});

// Ensure table exists
(async()=>{
  const sql=`
    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
    );`;
  await pool.execute(sql);
})();

// Middleware & static (serve heatmap.html as index)
app.use(bodyParser.json());
const publicDir = path.join(__dirname,'public');
app.use(express.static(publicDir, { 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   = new Date();
    const { shift, key, estNow } = getShiftInfo(now);
    shiftCounters[key]=(shiftCounters[key]||0)+1;
    const period  = shiftCounters[key];
    const sqlTs   = formatDateEST(estNow);
    const shortTs = shortEST(estNow);

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

    // SSE
    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 });

    // CSV
    const y=estNow.getFullYear(), m=pad2(estNow.getMonth()+1), d=pad2(estNow.getDate());
    const dateKey=`${y}${m}${d}`;
    const [rows] = await pool.execute(
      `SELECT * FROM readings WHERE DATE(timestamp)=CURDATE() ORDER BY timestamp`
    );
    let csvUrl=null;
    try{ csvUrl=await uploadTrendsCsv(dateKey,rows) }catch(e){console.error(e)}

    // weather
    const weather = await fetchCurrentWeather();

    // build text
    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 🥵`;

    const payload = { text };

    // send as url-encoded string
    const body = `payload=${encodeURIComponent(JSON.stringify(payload))}`;
    await axios.post(process.env.SLACK_WEBHOOK_URL, body, {
      headers:{ 'Content-Type':'application/x-www-form-urlencoded' }
    });

    res.json({ success:true, shift, period, csvUrl });
  } catch(err) {
    console.error('POST /api/readings 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 = new Date();
    const { shift, estNow } = getShiftInfo(now);
    const sqlTs   = formatDateEST(estNow);
    const shortTs = shortEST(estNow);

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

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

    // CSV
    const y=estNow.getFullYear(), m=pad2(estNow.getMonth()+1), d=pad2(estNow.getDate());
    const dateKey=`${y}${m}${d}`;
    const [rows] = await pool.execute(
      `SELECT * FROM readings WHERE DATE(timestamp)=CURDATE() ORDER BY timestamp`
    );
    let csvUrl=null;
    try{ csvUrl=await uploadTrendsCsv(dateKey,rows) }catch(e){console.error(e)}

    // weather
    const weather = await fetchCurrentWeather();

    // build text
    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 🥵`;

    const payload = { text };
    const body = `payload=${encodeURIComponent(JSON.stringify(payload))}`;
    await axios.post(process.env.SLACK_WEBHOOK_URL, body, {
      headers:{ 'Content-Type':'application/x-www-form-urlencoded' }
    });

    res.json({ success:true, csvUrl });
  } catch(err) {
    console.error('POST /api/area-readings error:',err);
    res.status(500).json({ error: err.message });
  }
});

// ---- GET all readings ----
app.get('/api/readings', async (req,res)=>{
  try {
    const [rows] = await pool.execute(`SELECT * FROM readings ORDER BY timestamp`);
    res.json(rows);
  } catch(err) {
    console.error('GET /api/readings error:',err);
    res.status(500).json({ error: err.message });
  }
});

// ---- CSV export ----
app.get('/api/export', async (req,res)=>{
  try {
    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=>{
      const ts = r.timestamp instanceof Date ? formatDateEST(r.timestamp) : r.timestamp;
      res.write(`${r.id},${r.location},${r.stationDockDoor},${ts},${r.temperature},${r.humidity},${r.heatIndex}\n`);
    });
    res.end();
  } catch(err) {
    console.error('GET /api/export error:',err);
    res.status(500).send(err.message);
  }
});

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