const express = require('express');
const puppeteer = require('puppeteer');
const { spawn } = require('child_process');
const path = require('path');
const fs = require('fs');
const https = require('https');

const app = express();
const PORT = process.env.PORT || 3000;
const MUSIC_PATH = process.env.MUSIC_PATH || '/music';

// Geocode city to lat/lon using Nominatim (OpenStreetMap)
async function geocodeCity(cityQuery) {
  return new Promise((resolve, reject) => {
    const encodedQuery = encodeURIComponent(cityQuery);
    const url = `https://nominatim.openstreetmap.org/search?q=${encodedQuery}&format=json&limit=1`;
    
    const options = {
      headers: {
        'User-Agent': 'webpage-to-hls-streaming-app/1.0'
      }
    };

    https.get(url, options, (res) => {
      let data = '';
      
      res.on('data', (chunk) => {
        data += chunk;
      });
      
      res.on('end', () => {
        try {
          const results = JSON.parse(data);
          if (results && results.length > 0) {
            resolve({
              lat: parseFloat(results[0].lat),
              lon: parseFloat(results[0].lon),
              displayName: results[0].display_name
            });
          } else {
            reject(new Error('No results found'));
          }
        } catch (error) {
          reject(error);
        }
      });
    }).on('error', (error) => {
      reject(error);
    });
  });
}

// Get random music file
function getRandomMusicFile() {
  try {
    if (!fs.existsSync(MUSIC_PATH)) {
      return null;
    }
    const files = fs.readdirSync(MUSIC_PATH).filter(f => f.endsWith('.ogg'));
    if (files.length === 0) {
      return null;
    }
    const randomFile = files[Math.floor(Math.random() * files.length)];
    return path.join(MUSIC_PATH, randomFile);
  } catch (error) {
    console.error('Error getting music file:', error);
    return null;
  }
}

// Get all music files for shuffling
function getAllMusicFiles() {
  try {
    if (!fs.existsSync(MUSIC_PATH)) {
      return [];
    }
    const files = fs.readdirSync(MUSIC_PATH).filter(f => f.endsWith('.ogg'));
    return files.map(f => path.join(MUSIC_PATH, f));
  } catch (error) {
    console.error('Error getting music files:', error);
    return [];
  }
}

// Shuffle array in place
function shuffleArray(array) {
  for (let i = array.length - 1; i > 0; i--) {
    const j = Math.floor(Math.random() * (i + 1));
    [array[i], array[j]] = [array[j], array[i]];
  }
  return array;
}

// Main streaming handler
async function streamHandler(req, res, useMusic = false) {
  const { url, width = 1920, height = 1080, fps = 30, hideLogo = 'false' } = req.query;

  if (!url) {
    return res.status(400).send('URL parameter is required');
  }

  // Validate URL
  try {
    new URL(url);
  } catch (error) {
    return res.status(400).send('Invalid URL');
  }

  let browser = null;
  let ffmpegProcess = null;
  let isCleaningUp = false;

  try {
    console.log(`Starting stream for: ${url}`);

    // Set HLS headers
    res.setHeader('Content-Type', 'application/vnd.apple.mpegurl');
    res.setHeader('Cache-Control', 'no-cache');
    res.setHeader('Connection', 'keep-alive');

    // Launch browser
    browser = await puppeteer.launch({
      headless: true,
      executablePath: process.env.PUPPETEER_EXECUTABLE_PATH || undefined,
      args: [
        '--no-sandbox',
        '--disable-setuid-sandbox',
        '--disable-dev-shm-usage',
        '--disable-gpu',
        `--window-size=${width},${height}`
      ],
      defaultViewport: { width: parseInt(width), height: parseInt(height) }
    });

    const page = await browser.newPage();
    await page.setViewport({ width: parseInt(width), height: parseInt(height) });
    await page.goto(url, { waitUntil: 'networkidle2', timeout: 30000 });

    // Hide logo if requested
    if (hideLogo === 'true') {
      await page.evaluate(() => {
        const images = document.querySelectorAll('img');
        images.forEach(img => {
          if (img.src && img.src.includes('Logo3.png')) {
            img.style.display = 'none';
          }
        });
      });
      console.log('Logo hidden');
    }

    console.log('Page loaded, starting FFmpeg...');

    // Build FFmpeg command with optional music
    const ffmpegArgs = [];
    let playlistFile = null;
    
    if (useMusic) {
      // Get all music files and shuffle them
      const allMusicFiles = getAllMusicFiles();
      if (allMusicFiles.length > 0) {
        const shuffledFiles = shuffleArray([...allMusicFiles]);
        
        // Create a temporary concat playlist file
        playlistFile = path.join('/tmp', `playlist-${Date.now()}.txt`);
        
        // Build playlist content - repeat the shuffled list multiple times to ensure we don't run out
        let playlistContent = '';
        for (let repeat = 0; repeat < 100; repeat++) {
          // Re-shuffle for each repeat to keep it truly random
          const currentShuffle = shuffleArray([...allMusicFiles]);
          currentShuffle.forEach(file => {
            playlistContent += `file '${file}'\n`;
          });
        }
        
        fs.writeFileSync(playlistFile, playlistContent);
        console.log(`Created shuffled playlist with ${allMusicFiles.length} unique tracks`);
        
        // Input 0: video frames
        ffmpegArgs.push(
          '-use_wallclock_as_timestamps', '1',
          '-f', 'image2pipe',
          '-framerate', fps.toString(),
          '-i', 'pipe:0'
        );
        // Input 1: audio from concat playlist
        ffmpegArgs.push(
          '-f', 'concat',
          '-safe', '0',
          '-i', playlistFile
        );
        // Encoding
        ffmpegArgs.push(
          '-c:v', 'libx264',
          '-preset', 'ultrafast',
          '-tune', 'zerolatency',
          '-pix_fmt', 'yuv420p',
          '-g', (fps * 2).toString(),
          '-c:a', 'aac',
          '-b:a', '128k',
          '-shortest',
          '-f', 'hls',
          '-hls_time', '2',
          '-hls_list_size', '5',
          '-hls_flags', 'delete_segments',
          'pipe:1'
        );
      } else {
        console.warn('No music files found, streaming without audio');
        useMusic = false;
      }
    }
    
    if (!useMusic) {
      // Video only (no music)
      ffmpegArgs.push(
        '-use_wallclock_as_timestamps', '1',
        '-f', 'image2pipe',
        '-framerate', fps.toString(),
        '-i', 'pipe:0',
        '-c:v', 'libx264',
        '-preset', 'ultrafast',
        '-tune', 'zerolatency',
        '-pix_fmt', 'yuv420p',
        '-g', (fps * 2).toString(),
        '-f', 'hls',
        '-hls_time', '2',
        '-hls_list_size', '5',
        '-hls_flags', 'delete_segments',
        'pipe:1'
      );
    }

    // Start FFmpeg
    ffmpegProcess = spawn('ffmpeg', ffmpegArgs);

    // Pipe FFmpeg output to response
    ffmpegProcess.stdout.pipe(res);

    ffmpegProcess.stderr.on('data', (data) => {
      // Suppress verbose FFmpeg output
      // console.error(`FFmpeg: ${data}`);
    });

    ffmpegProcess.on('error', (error) => {
      console.error('FFmpeg error:', error);
      cleanup();
    });

    ffmpegProcess.stdin.on('error', (error) => {
      // Ignore EPIPE errors when client disconnects
      if (error.code !== 'EPIPE') {
        console.error('FFmpeg stdin error:', error);
      }
    });

    // Capture frames using a sequential loop (avoids overlapping screenshots)
    // and handle backpressure on ffmpeg.stdin (wait for 'drain' with timeout).
    const frameInterval = 1000 / fps;
    let captureLoopActive = true;

    const captureLoop = async () => {
      while (!isCleaningUp && captureLoopActive && ffmpegProcess && !ffmpegProcess.killed) {
        const start = Date.now();
        try {
          // Take a screenshot (lower quality a bit to reduce CPU/pipe pressure)
          const screenshot = await page.screenshot({ type: 'jpeg', quality: 70 });

          if (ffmpegProcess && ffmpegProcess.stdin.writable && !isCleaningUp) {
            const canWrite = ffmpegProcess.stdin.write(screenshot);
            if (!canWrite) {
              // Backpressure — wait for drain but don't block forever
              await new Promise((resolve) => {
                let resolved = false;
                const onDrain = () => { if (!resolved) { resolved = true; cleanupListeners(); resolve(); } };
                const onError = () => { if (!resolved) { resolved = true; cleanupListeners(); resolve(); } };
                const timeout = setTimeout(() => { if (!resolved) { resolved = true; cleanupListeners(); resolve(); } }, 800);
                function cleanupListeners() {
                  clearTimeout(timeout);
                  ffmpegProcess.stdin.removeListener('drain', onDrain);
                  ffmpegProcess.stdin.removeListener('error', onError);
                }
                ffmpegProcess.stdin.once('drain', onDrain);
                ffmpegProcess.stdin.once('error', onError);
              });
            }
          }
        } catch (error) {
          if (!isCleaningUp) {
            console.error('Capture error:', error.message || error);
            try { await cleanup(); } catch (e) {}
            break;
          }
        }

        const elapsed = Date.now() - start;
        const wait = Math.max(0, frameInterval - elapsed);
        // Wait the remaining time before next frame
        if (wait > 0) await new Promise(r => setTimeout(r, wait));
      }
    };

    // Start the capture loop (no overlapping runs)
    captureLoop();

    // Cleanup function
    const cleanup = async () => {
      if (isCleaningUp) return;
      isCleaningUp = true;
      // stop capture loop
      try { captureLoopActive = false; } catch (e) {}
      
      if (ffmpegProcess && !ffmpegProcess.killed) {
        try {
          ffmpegProcess.stdin.end();
        } catch (err) {
          // Ignore errors during cleanup
        }
        ffmpegProcess.kill('SIGTERM');
        ffmpegProcess = null;
      }
      
      // Clean up temporary playlist file
      if (playlistFile) {
        try {
          fs.unlinkSync(playlistFile);
        } catch (err) {
          // Ignore errors during cleanup
        }
      }
      
      if (browser) {
        try {
          await browser.close();
        } catch (err) {
          // Ignore errors during cleanup
        }
        browser = null;
      }
      
      if (!res.headersSent && !res.writableEnded) {
        res.end();
      }
  };

    // Handle client disconnect
    req.on('close', () => {
      console.log('Client disconnected');
      cleanup();
    });

    res.on('error', (error) => {
      console.error('Response error:', error);
      cleanup();
    });

  } catch (error) {
    console.error('Error:', error);
    if (ffmpegProcess && !ffmpegProcess.killed) ffmpegProcess.kill();
    if (browser) await browser.close();
    if (!res.headersSent) {
      res.status(500).send('Internal server error');
    }
  }
}

// Stream endpoint
app.get('/stream', (req, res) => streamHandler(req, res, false));

app.get('/weather', async (req, res) => {
  const { 
    city = 'Toronto, ON, CAN',
    width = 1920,
    height = 1080,
    fps = 30,
    hideLogo = 'false',
    units = 'metric', // 'metric' or 'imperial'
    timeFormat = '24h', // '12h' or '24h'
    // Forecast section toggles - commonly used sections (default: true)
    showHazards = 'true',
    showCurrent = 'true',
    showHourly = 'true',
    showHourlyGraph = 'true',
    showLocalForecast = 'true',
    showExtendedForecast = 'true',
    showRadar = 'true',
    showAQI = 'true',
    showAlmanac = 'true',
    showLatestObservations = 'true',
    showRegionalForecast = 'true',
    // Less common sections (default: false)
    showTravel = 'false',
    showMarineForecast = 'false'
  } = req.query;

  // Default coordinates (Toronto, ON, Canada)
  let lat = 43.6532;
  let lon = -79.3832;
  
  // Try to geocode the city if provided
  if (city) {
    try {
      console.log(`Geocoding city: ${city}`);
      const geoResult = await geocodeCity(city);
      lat = geoResult.lat;
      lon = geoResult.lon;
      console.log(`Geocoded to: ${geoResult.displayName} (${lat}, ${lon})`);
    } catch (error) {
      console.warn(`Geocoding failed for "${city}", using default coordinates:`, error.message);
      // Fall back to defaults
    }
  }

  // Unit conversions for ws4kp
  // Temperature: 1.00=Celsius, 2.00=Fahrenheit
  // Wind: 1.00=kph, 2.00=mph
  // Distance: 1.00=km, 2.00=miles
  // Pressure: 1.00=mb, 2.00=inHg
  // Hours: 1.00=12h, 2.00=24h
  const isMetric = units.toLowerCase() === 'metric';
  const temperatureUnit = isMetric ? '1.00' : '2.00';
  const windUnit = isMetric ? '1.00' : '2.00';
  const distanceUnit = isMetric ? '1.00' : '2.00';
  const pressureUnit = isMetric ? '1.00' : '2.00';
  const hoursFormat = timeFormat === '12h' ? '1.00' : '2.00';

  // Build the ws4kp URL with all the parameters
  // ws4kp runs on port 8080 inside the container
  const ws4kpBaseUrl = process.env.WS4KP_URL || 'http://localhost:8080';
  const ws4kpParams = new URLSearchParams({
    'hazards-checkbox': showHazards,
    'current-weather-checkbox': showCurrent,
    'latest-observations-checkbox': showLatestObservations,
    'hourly-checkbox': showHourly,
    'hourly-graph-checkbox': showHourlyGraph,
    'travel-checkbox': showTravel,
    'regional-forecast-checkbox': showRegionalForecast,
    'local-forecast-checkbox': showLocalForecast,
    'extended-forecast-checkbox': showExtendedForecast,
    'almanac-checkbox': showAlmanac,
    'radar-checkbox': showRadar,
    'marine-forecast-checkbox': showMarineForecast,
    'aqi-forecast-checkbox': showAQI,
    'settings-experimentalFeatures-checkbox': 'false',
    'settings-hideWebamp-checkbox': 'true',
    'settings-kiosk-checkbox': 'false',
    'settings-scanLines-checkbox': 'false',
    'settings-wide-checkbox': 'true',
    'chkAutoRefresh': 'true',
    'settings-windUnits-select': windUnit,
    'settings-marineWindUnits-select': '1.00',
    'settings-marineWaveHeightUnits-select': '1.00',
    'settings-temperatureUnits-select': temperatureUnit,
    'settings-distanceUnits-select': distanceUnit,
    'settings-pressureUnits-select': pressureUnit,
    'settings-hoursFormat-select': hoursFormat,
    'settings-speed-select': '1.00',
    'latLonQuery': city,
    'latLon': JSON.stringify({ lat: lat, lon: lon }),
    'kiosk': 'true'
  });

  const weatherUrl = `${ws4kpBaseUrl}/?${ws4kpParams.toString()}`;
  
  console.log(`Weather stream requested for: ${city} (${lat}, ${lon})`);
  
  // Forward to the main stream endpoint WITH MUSIC
  req.query.url = weatherUrl;
  req.query.width = width;
  req.query.height = height;
  req.query.fps = fps;
  req.query.hideLogo = hideLogo;
  
  // Call the stream handler with music enabled
  return streamHandler(req, res, true);
});

app.get('/health', (req, res) => {
  res.send('OK');
});

app.listen(PORT, () => {
  console.log(`Webpage to HLS server running on port ${PORT}`);
  console.log(`Usage: http://localhost:${PORT}/stream?url=http://example.com`);
  console.log(`Weather: http://localhost:${PORT}/weather?city=YourCity`);
});