const { app, BrowserWindow, ipcMain, shell, Tray, Menu, nativeImage, clipboard, session, desktopCapturer } = require('electron');
const path = require('path');
const fs = require('fs');
const { exec } = require('child_process');
const { promisify } = require('util');
const Store = require('electron-store');
const open = require('open');
const { autoUpdater } = require('electron-updater');
const PaarrotAPIServer = require('./api-server');

const execAsync = promisify(exec);
const store = new Store();

let mainWindow = null;
let tray = null;
let isQuitting = false;
let apiServer = null;

// Configure auto-updater
autoUpdater.autoDownload = false;
autoUpdater.autoInstallOnAppQuit = true;

// Auto-updater event handlers
autoUpdater.on('checking-for-update', () => {
  console.log('Checking for updates...');
});

autoUpdater.on('update-available', (info) => {
  console.log('Update available:', info.version);
  if (mainWindow) {
    mainWindow.webContents.send('update-available', info);
  }
});

autoUpdater.on('update-not-available', (info) => {
  console.log('No updates available');
});

autoUpdater.on('error', (err) => {
  console.error('Auto-updater error:', err);
});

autoUpdater.on('download-progress', (progressObj) => {
  console.log(`Download progress: ${progressObj.percent}%`);
  if (mainWindow) {
    mainWindow.webContents.send('update-download-progress', progressObj);
  }
});

autoUpdater.on('update-downloaded', (info) => {
  console.log('Update downloaded:', info.version);
  if (mainWindow) {
    mainWindow.webContents.send('update-downloaded', info);
  }
});


// Single instance lock
const gotTheLock = app.requestSingleInstanceLock();

if (!gotTheLock) {
  app.quit();
} else {
  app.on('second-instance', () => {
    // Someone tried to run a second instance, focus our window
    if (mainWindow) {
      if (mainWindow.isMinimized()) mainWindow.restore();
      mainWindow.show();
      mainWindow.focus();
    }
  });
}

// Development mode detection
const isDev = process.env.NODE_ENV === 'development' || !app.isPackaged;
const VITE_DEV_SERVER = 'http://localhost:8080';
const PORT = 44548;

// Helper to get correct icon path in dev vs packaged app
function getIconPath(iconName) {
  if (isDev) {
    return path.join(__dirname, '../icons', iconName);
  }
  // In packaged app, extraResources puts icons in resources/icons/
  return path.join(process.resourcesPath, 'icons', iconName);
}

function createWindow() {
  // Restore window state or use defaults
  const windowState = store.get('windowState', {
    width: 1280,
    height: 905,
    x: undefined,
    y: undefined,
    isMaximized: false
  });

  mainWindow = new BrowserWindow({
    width: windowState.width,
    height: windowState.height,
    x: windowState.x,
    y: windowState.y,
    title: 'Paarrot',
    frame: false, // Custom window decorations
    resizable: true,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      contextIsolation: true,
      nodeIntegration: false,
      webSecurity: true,
      allowRunningInsecureContent: false,
      // Enable navigation gestures (works on macOS and some Linux environments)
      enableBlinkFeatures: 'OverscrollHistoryNavigation'
    },
    icon: getIconPath(process.platform === 'win32' ? 'icon.ico' : 'icon.png'),
    show: false // Don't show until ready
  });

  // Enable trackpad swipe gestures for navigation on macOS
  if (process.platform === 'darwin') {
    try {
      mainWindow.on('swipe', (event, direction) => {
        console.log(`Paarrot: Swipe gesture detected: ${direction}`);
        if (direction === 'left' && mainWindow.webContents.canGoForward()) {
          console.log('Paarrot: Navigating forward');
          mainWindow.webContents.goForward();
        } else if (direction === 'right' && mainWindow.webContents.canGoBack()) {
          console.log('Paarrot: Navigating back');
          mainWindow.webContents.goBack();
        }
      });
    } catch (error) {
      console.error('Paarrot: Failed to set up swipe gestures:', error);
    }
  }
  
  // On Linux, the OverscrollHistoryNavigation Blink feature should handle it automatically
  // On Windows, mouse buttons 4 & 5 are typically used for navigation (handled by Chromium)

  // Restore maximized state
  if (windowState.isMaximized) {
    mainWindow.maximize();
  }

  // Save window state on resize/move
  const saveWindowState = () => {
    if (!mainWindow.isMaximized() && !mainWindow.isMinimized() && !mainWindow.isFullScreen()) {
      const bounds = mainWindow.getBounds();
      store.set('windowState', {
        width: bounds.width,
        height: bounds.height,
        x: bounds.x,
        y: bounds.y,
        isMaximized: false
      });
    }
  };

  mainWindow.on('resize', saveWindowState);
  mainWindow.on('move', saveWindowState);
  mainWindow.on('maximize', () => {
    store.set('windowState.isMaximized', true);
  });
  mainWindow.on('unmaximize', () => {
    store.set('windowState.isMaximized', false);
  });

  // Set up session handlers BEFORE loading the app
  // Auto-approve media permissions including screen capture
  mainWindow.webContents.session.setPermissionRequestHandler((webContents, permission, callback) => {
    const allowedPermissions = ['media', 'microphone', 'camera', 'display-capture'];
    
    if (allowedPermissions.includes(permission)) {
      console.log(`Paarrot: Auto-approving permission: ${permission}`);
      callback(true);
    } else {
      console.log(`Paarrot: Denying permission: ${permission}`);
      callback(false);
    }
  });

  // Handle screen capture requests - always allow
  mainWindow.webContents.session.setPermissionCheckHandler((webContents, permission, requestingOrigin, details) => {
    console.log(`Paarrot: Permission check - ${permission} from ${requestingOrigin}`);
    return true; // Allow all permissions
  });

  // Handle display media request (screen sharing) - this is the key for Electron screen capture
  mainWindow.webContents.session.setDisplayMediaRequestHandler(async (request, callback) => {
    console.log('Paarrot: Display media request received', request);
    
    try {
      const sources = await desktopCapturer.getSources({
        types: ['screen', 'window'],
        thumbnailSize: { width: 150, height: 150 }
      });
      
      console.log('Paarrot: Available sources:', sources.length);
      sources.forEach((s, i) => console.log(`  ${i}: ${s.name} (${s.id})`));
      
      if (sources.length === 0) {
        console.log('Paarrot: No sources available, denying request');
        callback({});
        return;
      }
      
      // Prefer screens over windows
      const source = sources.find(s => s.id.startsWith('screen:')) || sources[0];
      console.log('Paarrot: Selected source:', source.name, source.id);
      
      // Return the selected source - video is required
      callback({ video: source });
    } catch (error) {
      console.error('Paarrot: Error getting display sources:', error);
      callback({});
    }
  }, { useSystemPicker: false });

  // Disable default context menu, only show for text selection
  mainWindow.webContents.on('context-menu', (event, params) => {
    const { selectionText, isEditable } = params;
    
    // Only show context menu if there's selected text or in an editable field
    if (selectionText || isEditable) {
      // Build a minimal menu for text operations
      const template = [];
      
      if (params.misspelledWord) {
        // Add spelling suggestions
        params.dictionarySuggestions.slice(0, 5).forEach(suggestion => {
          template.push({
            label: suggestion,
            click: () => mainWindow.webContents.replaceMisspelling(suggestion)
          });
        });
        if (template.length > 0) {
          template.push({ type: 'separator' });
        }
      }
      
      if (selectionText) {
        template.push(
          {
            label: 'Copy',
            role: 'copy',
            accelerator: 'CmdOrCtrl+C'
          }
        );
      }
      
      if (isEditable) {
        if (selectionText) {
          template.push(
            {
              label: 'Cut',
              role: 'cut',
              accelerator: 'CmdOrCtrl+X'
            }
          );
        }
        template.push(
          {
            label: 'Paste',
            role: 'paste',
            accelerator: 'CmdOrCtrl+V'
          }
        );
        if (selectionText) {
          template.push({ type: 'separator' });
          template.push(
            {
              label: 'Select All',
              role: 'selectAll',
              accelerator: 'CmdOrCtrl+A'
            }
          );
        }
      }
      
      if (template.length > 0) {
        const menu = Menu.buildFromTemplate(template);
        menu.popup(mainWindow);
      }
    }
    // If no text selected and not editable, suppress the context menu entirely
  });

  // Load the app
  if (isDev) {
    mainWindow.loadURL(VITE_DEV_SERVER);
    // Open DevTools in development
    mainWindow.webContents.openDevTools();
  } else {
    // In production, serve from built files
    mainWindow.loadFile(path.join(__dirname, '../cinny/dist/index.html'));
  }

  // Show window when ready
  mainWindow.once('ready-to-show', () => {
    // Check for --minimized flag (autostart)
    if (!process.argv.includes('--minimized')) {
      mainWindow.show();
    }
  });

  // Handle window close - minimize to tray
  mainWindow.on('close', (event) => {
    if (!isQuitting) {
      event.preventDefault();
      mainWindow.hide();
      return false;
    }
  });

  mainWindow.on('closed', () => {
    mainWindow = null;
  });

  // Open external links in default browser
  mainWindow.webContents.setWindowOpenHandler(({ url }) => {
    if (url.startsWith('http://') || url.startsWith('https://')) {
      shell.openExternal(url);
      return { action: 'deny' };
    }
    return { action: 'allow' };
  });

  // Navigation handler - open external links in browser
  mainWindow.webContents.on('will-navigate', (event, url) => {
    const allowedOrigins = [
      'http://localhost:8080',
      'http://localhost:44548',
      'http://127.0.0.1:8080',
      'http://127.0.0.1:44548'
    ];
    
    const isAllowed = allowedOrigins.some(origin => url.startsWith(origin)) ||
                      url.startsWith('blob:') ||
                      url.startsWith('data:');
    
    if (!isAllowed && (url.startsWith('http://') || url.startsWith('https://'))) {
      event.preventDefault();
      shell.openExternal(url);
    }
  });

  return mainWindow;
}

function createTray() {
  const iconPath = getIconPath('icon.png');
  const trayIcon = nativeImage.createFromPath(iconPath);
  tray = new Tray(trayIcon.resize({ width: 16, height: 16 }));

  const contextMenu = Menu.buildFromTemplate([
    {
      label: 'Show Paarrot',
      click: () => {
        if (mainWindow) {
          mainWindow.show();
          mainWindow.focus();
        }
      }
    },
    { type: 'separator' },
    {
      label: 'Quit',
      click: () => {
        isQuitting = true;
        app.quit();
      }
    }
  ]);

  tray.setContextMenu(contextMenu);
  tray.setToolTip('Paarrot');

  // Click tray icon to show window
  tray.on('click', () => {
    if (mainWindow) {
      if (mainWindow.isVisible()) {
        mainWindow.hide();
      } else {
        mainWindow.show();
        mainWindow.focus();
      }
    }
  });
}

// App lifecycle
app.whenReady().then(() => {
  createWindow();
  createTray();
  
  // Start API server
  apiServer = new PaarrotAPIServer(mainWindow);
  apiServer.start().catch(err => {
    console.error('Failed to start API server:', err);
  });
  
  // Check for updates (not in development mode)
  if (!isDev) {
    // Check for updates on start (after 3 seconds)
    setTimeout(() => {
      autoUpdater.checkForUpdates().catch(err => {
        console.error('Failed to check for updates:', err);
      });
    }, 3000);
    
    // Check for updates every 6 hours
    setInterval(() => {
      autoUpdater.checkForUpdates().catch(err => {
        console.error('Failed to check for updates:', err);
      });
    }, 6 * 60 * 60 * 1000);
  }
});

app.on('window-all-closed', () => {
  // On macOS, apps stay active until Cmd+Q
  if (process.platform !== 'darwin') {
    // But we want to stay in tray, so don't quit
    // app.quit();
  }
});

app.on('activate', () => {
  // On macOS, recreate window when dock icon is clicked
  if (BrowserWindow.getAllWindows().length === 0) {
    createWindow();
  } else if (mainWindow) {
    mainWindow.show();
  }
});

app.on('before-quit', () => {
  isQuitting = true;
  
  // Stop API server
  if (apiServer) {
    apiServer.stop();
  }
});

// ==================== IPC Handlers ====================

// Window controls
ipcMain.handle('window:minimize', () => {
  if (mainWindow) mainWindow.minimize();
});

ipcMain.handle('window:maximize', () => {
  if (mainWindow) {
    if (mainWindow.isMaximized()) {
      mainWindow.unmaximize();
    } else {
      mainWindow.maximize();
    }
  }
});

ipcMain.handle('window:unmaximize', () => {
  if (mainWindow) mainWindow.unmaximize();
});

ipcMain.handle('window:close', () => {
  if (mainWindow) mainWindow.close();
});

ipcMain.handle('window:is-maximized', () => {
  return mainWindow ? mainWindow.isMaximized() : false;
});

ipcMain.handle('window:start-drag', () => {
  if (mainWindow) mainWindow.webContents.startDrag({ file: '', icon: nativeImage.createEmpty() });
});

// Get app version (Tauri-compatible API)
ipcMain.handle('plugin:app|version', () => {
  return app.getVersion();
});

// Open external URL
ipcMain.handle('open-external-url', async (event, url) => {
  try {
    await shell.openExternal(url);
    return { success: true };
  } catch (error) {
    return { success: false, error: error.message };
  }
});

// Read clipboard image
ipcMain.handle('read-clipboard-image', async () => {
  try {
    const image = clipboard.readImage();
    if (image.isEmpty()) {
      return { success: true, data: null };
    }
    
    // Convert to PNG base64
    const pngBuffer = image.toPNG();
    const base64 = pngBuffer.toString('base64');
    return { 
      success: true, 
      data: `data:image/png;base64,${base64}` 
    };
  } catch (error) {
    return { success: false, error: error.message };
  }
});

// Get YouTube stream using yt-dlp
ipcMain.handle('get-youtube-stream', async (event, url) => {
  try {
    // Check if yt-dlp is available
    try {
      await execAsync('yt-dlp --version');
    } catch {
      return { 
        success: false, 
        error: 'yt-dlp is not installed. Please install yt-dlp to use YouTube features.' 
      };
    }

    // Get title
    let title = 'YouTube Video';
    try {
      const titleResult = await execAsync(`yt-dlp --get-title "${url}"`);
      title = titleResult.stdout.trim();
    } catch (e) {
      console.warn('Failed to get video title:', e.message);
    }

    // Get video URL
    const result = await execAsync(
      `yt-dlp -g -f "best[height<=1080]/bestvideo[height<=1080]+bestaudio/best" "${url}"`
    );
    
    const videoUrl = result.stdout.trim().split('\n')[0];
    
    if (!videoUrl) {
      return { success: false, error: 'yt-dlp returned empty URL' };
    }

    return { 
      success: true, 
      data: { video_url: videoUrl, title } 
    };
  } catch (error) {
    return { 
      success: false, 
      error: `yt-dlp error: ${error.message}` 
    };
  }
});

// Background sync stubs (desktop doesn't need it)
ipcMain.handle('start-background-sync', async () => {
  return { success: true };
});

ipcMain.handle('stop-background-sync', async () => {
  return { success: true };
});

ipcMain.handle('get-background-sync-state', async () => {
  return { success: true, data: 'NotApplicable' };
});

// Auto-updater IPC handlers
ipcMain.handle('check-for-updates', async () => {
  try {
    const result = await autoUpdater.checkForUpdates();
    return { success: true, data: result };
  } catch (error) {
    return { success: false, error: error.message };
  }
});

ipcMain.handle('download-update', async () => {
  try {
    await autoUpdater.downloadUpdate();
    return { success: true };
  } catch (error) {
    return { success: false, error: error.message };
  }
});

ipcMain.handle('install-update', () => {
  autoUpdater.quitAndInstall(false, true);
  return { success: true };
});

// Screen capture / desktopCapturer handler
ipcMain.handle('get-desktop-sources', async (event, opts) => {
  try {
    const sources = await desktopCapturer.getSources(opts);
    return { success: true, data: sources };
  } catch (error) {
    console.error('Failed to get desktop sources:', error);
    return { success: false, error: error.message };
  }
});

console.log('Paarrot Electron main process started');
console.log('Development mode:', isDev);
console.log('Platform:', process.platform);