const { app, BrowserWindow, ipcMain, Menu, dialog, powerSaveBlocker, safeStorage } = require('electron');
const path = require('path');
const fs = require('fs-extra');
const { pathToFileURL } = require('url');
const { startLlamaServer, stopLlamaServer, ensureLlamaStarting } = require('./llama-launcher.cjs');

// Keep the renderer fully awake on an idle stage TV. Without these, Chromium throttles/freezes
// a window it thinks is backgrounded or occluded after a few minutes — which caused the splash
// to need a "wake-up" tap before the real dismiss tap registered. These flags are safe (they do
// NOT touch GPU compositing) and make the very first tap always count.
app.commandLine.appendSwitch('disable-background-timer-throttling');
app.commandLine.appendSwitch('disable-renderer-backgrounding');
app.commandLine.appendSwitch('disable-backgrounding-occluded-windows');

// Keep the DISPLAY awake while the app runs. If Windows turns the screen off (or the screensaver
// kicks in) after the TV sits idle, the OS consumes the first tap just to wake the display — that
// was the remaining "throwaway tap" on the splash. A live stage TV must never sleep mid-service.
let __psbId = null;
function ensureDisplayAwake() {
  try {
    if (__psbId === null || !powerSaveBlocker.isStarted(__psbId)) {
      __psbId = powerSaveBlocker.start('prevent-display-sleep');
      console.log('[MAIN] Display sleep blocked (powerSaveBlocker id ' + __psbId + ')');
    }
  } catch (e) {
    console.warn('[MAIN] Could not block display sleep:', e && e.message || e);
  }
}

let serverStarted = false;
let serverModuleRef = null;
let captureBusy = false;   // one window capture at a time — see captureScreen in registerAppControl

/*
 * Fast mirror path for the phone remote (see captureScreen): the RENDERER captures its own window
 * through getDisplayMedia and answers with ready-encoded JPEGs — ~20-40ms a frame where
 * capturePage() has a fixed ~120ms GPU-readback floor on the 4K stage window, and the encode work
 * happens off the main process entirely. capturePage stays as the fallback: first requests while
 * the stream warms up, and permanently if the renderer reports the capture API can't work.
 */
let mirrorReqId = 0;
const mirrorPending = new Map();       // id -> { resolve, timer }
let mirrorRendererBroken = false;      // renderer said self-capture cannot work — stop asking

ipcMain.on('mirror:frame-response', (_evt, msg) => {
  try {
    const rec = msg && mirrorPending.get(msg.id);
    if (!rec) return;
    clearTimeout(rec.timer);
    mirrorPending.delete(msg.id);
    if (msg.fatal) {
      mirrorRendererBroken = true;
      console.warn('[MIRROR] Renderer self-capture unavailable (' + (msg.error || 'unknown') + '); falling back to capturePage');
    }
    if (msg.unchanged) { rec.resolve({ unchanged: true }); return; }
    if (msg.error || !msg.buf) { rec.resolve(null); return; }
    rec.resolve({ jpeg: Buffer.from(msg.buf), width: msg.w, height: msg.h, sc: msg.sc, sm: msg.sm, iv: msg.iv });
  } catch (_) { try { const rec = mirrorPending.get(msg && msg.id); if (rec) rec.resolve(null); } catch (_) {} }
});

/*
 * Which port the app window loads from.
 *
 * ASK THE SERVER FIRST. server-port.txt is only a fallback for a dev run, and is deliberately NOT
 * trusted in a packaged build: __dirname is inside app.asar there, so the server cannot rewrite the
 * file and a stale port baked in at build time would be believed forever. That exact thing shipped
 * once — a leftover "8081" from a dev session got packaged, the window failed to load, fell back to
 * file://index.html, and the app came up with no server behind it: default graphics, none of the
 * operator's content, and Content Manager pointing at file:///C:/content-manager.html.
 */
function resolveServerPort() {
  try {
    if (serverModuleRef && typeof serverModuleRef.getServerPort === 'function') {
      const live = Number(serverModuleRef.getServerPort());
      if (live > 0) return String(live);
    }
  } catch (_) {}
  return resolveServerPortFallback();
}
/*
 * Wait for the socket to be bound, then use the port it actually got. Without this the window can be
 * loaded before the server binds, fall back to 8080, and — if something else already holds 8080 —
 * attach to a foreign server while our own sits on 8081.
 */
async function awaitServerPort(timeoutMs = 8000) {
  try {
    if (serverModuleRef && typeof serverModuleRef.whenServerListening === 'function') {
      const port = await Promise.race([
        serverModuleRef.whenServerListening(),
        new Promise((resolve) => setTimeout(() => resolve(null), timeoutMs))
      ]);
      if (port) return String(port);
      console.warn('[MAIN] server did not report a listening port in time; using best guess');
    }
  } catch (_) {}
  return resolveServerPort();
}
function resolveServerPortFallback() {
  try {
    if (!app.isPackaged) {
      const portFile = path.join(__dirname, 'server-port.txt');
      if (fs.existsSync(portFile)) {
        const fromFile = String(fs.readFileSync(portFile, 'utf-8')).trim();
        if (fromFile) return fromFile;
      }
    }
  } catch (_) {}
  return '8080';
}
function resolveUserContentRoot() {
  try {
    const root = path.join(app.getPath('userData'), 'user-content');
    fs.ensureDirSync(root);
    return root;
  } catch (e) {
    const fallback = path.join(process.cwd(), 'user-content');
    fs.ensureDirSync(fallback);
    console.warn('[MAIN] Falling back to cwd for user-content:', e.message || e);
    return fallback;
  }
}

function migrateLegacyDir(label, targetDir, sources) {
  try {
    fs.ensureDirSync(targetDir);
    sources
      .filter(Boolean)
      .forEach(src => {
        if (!src || src === targetDir) return;
        if (!fs.existsSync(src)) return;
        const entries = fs.readdirSync(src);
        if (!entries.length) return;
        entries.forEach(name => {
          const from = path.join(src, name);
          const to = path.join(targetDir, name);
          try {
            if (fs.existsSync(to)) return;
            const stat = fs.statSync(from);
            if (stat.isDirectory()) {
              fs.copySync(from, to, { overwrite: false, errorOnExist: false });
            } else if (stat.isFile()) {
              fs.copyFileSync(from, to, fs.constants.COPYFILE_EXCL);
            }
          } catch (_) { /* ignore per-file copy issues */ }
        });
        console.log(`[MAIN] Migrated ${label} from ${src} -> ${targetDir}`);
      });
  } catch (e) {
    console.warn(`[MAIN] Failed to migrate ${label}:`, e.message || e);
  }
}

async function startLocalHttpServer() {
  if (serverStarted) return;
  try {
    const execDir = path.dirname(process.execPath || '');
    const userContentRoot = resolveUserContentRoot();
    const notesDir = path.join(userContentRoot, 'Notes');
    const announcementsDir = path.join(userContentRoot, 'Announcements');

    // Ensure persistent directories exist and pull forward any legacy assets
    fs.ensureDirSync(notesDir);
    fs.ensureDirSync(announcementsDir);
    migrateLegacyDir('Notes', notesDir, [
      path.join(execDir, 'Notes'),
      path.join(__dirname, 'Notes'),
      path.join(process.cwd(), 'Notes')
    ]);
    migrateLegacyDir('Announcements', announcementsDir, [
      path.join(execDir, 'Announcements'),
      path.join(__dirname, 'Announcements'),
      path.join(process.cwd(), 'Announcements')
    ]);
    
    console.log(`[MAIN] Notes directory: ${notesDir}`);
    console.log(`[MAIN] Announcements directory: ${announcementsDir}`);
    console.log(`[MAIN] User content root: ${userContentRoot}`);
    
    // Set environment variables so server.js can use them
    process.env.BIBLE_APP_DATA_DIR = userContentRoot;
    process.env.BIBLE_APP_USER_DATA_DIR = userContentRoot;
    process.env.BIBLE_APP_NOTES_DIR = notesDir;
    process.env.BIBLE_APP_ANNOUNCEMENTS_DIR = announcementsDir;
    
    const serverModuleUrl = pathToFileURL(path.join(__dirname, 'server.js')).href;
    serverModuleRef = await import(serverModuleUrl);
    serverStarted = true;
    // server.js logs its own startup message and binds to 8080 (falls back to 8081 if busy)
  } catch (error) {
    console.error('Failed to start embedded HTTP server:', error);
  }
}

async function createWindow () {
  const win = new BrowserWindow({
    width: 1200,
    height: 900,
    fullscreen: true,
    autoHideMenuBar: true,
    backgroundColor: '#1a1a1a',
    show: true,
    webPreferences: {
      nodeIntegration: false,
      contextIsolation: true,
      webSecurity: true, // Same-origin policy ON. App content is served over http://localhost,
                          // so file:// access is unnecessary; external APIs used are CORS-enabled.
      backgroundThrottling: false, // never throttle timers/paint when idle — first tap always registers
      preload: path.join(__dirname, 'preload.cjs'),
      devTools: true // Enable DevTools for debugging
    }
  });

  /*
   * Let the renderer capture ITS OWN window for the phone mirror, with no picker dialog: any
   * getDisplayMedia call from this window is answered with this window as the source. Nothing else
   * in the app calls getDisplayMedia, and the request can only come from our own loaded page.
   *
   * The source is the OS WINDOW via desktopCapturer, NOT webContents.mainFrame: tab capture of this
   * app was observed freezing after the first frames (annotation canvas layers never invalidated
   * it), where OS window capture duplicates the real composited output and keeps flowing.
   */
  try {
    const { desktopCapturer } = require('electron');
    win.webContents.session.setDisplayMediaRequestHandler((request, callback) => {
      desktopCapturer.getSources({ types: ['window'] }).then((sources) => {
        let src = null;
        try {
          const mid = win.getMediaSourceId();
          src = sources.find(s => s.id === mid) || null;
        } catch (_) {}
        callback(src ? { video: src } : {});
      }).catch((e) => {
        console.warn('[MIRROR] display-media source lookup failed:', e && e.message);
        try { callback({}); } catch (_) {}
      });
    }, { useSystemPicker: false });
    console.log('[MIRROR] Self-capture handler installed for the phone mirror');
  } catch (e) {
    console.warn('[MIRROR] setDisplayMediaRequestHandler unavailable:', e && e.message);
  }
  // A reloaded page gets a fresh chance at self-capture (reset_app, crash recovery).
  win.webContents.on('did-finish-load', () => { mirrorRendererBroken = false; });

  // Enable DevTools with keyboard shortcut (F12)
  // Also add menu option for DevTools
  win.webContents.on('before-input-event', (event, input) => {
    if (input.key === 'F12' || (input.control && input.shift && input.key === 'I')) {
      if (win.webContents.isDevToolsOpened()) {
        win.webContents.closeDevTools();
      } else {
        win.webContents.openDevTools();
      }
    }
  });

  // Build a minimal Help menu with Content Manager and About options
  try { setupAppMenu(win); } catch (_) {}

  // Start the embedded server and load the app via HTTP so relative API routes work
  await startLocalHttpServer();

  // Start the bundled llama.cpp inference server so the Ask tab works offline
  // out of the box. This is non-blocking; if it fails the Ask tab gracefully
  // shows a fallback message.
  try { ensureLlamaStarting().catch((e) => { console.error('[MAIN] startLlamaServer failed:', e); }); } catch (e) { console.error('[MAIN] startLlamaServer failed:', e); }
  
  // Register renderer invoker EARLY so OSC commands work immediately
  // This must happen before OSC listener starts (which happens 500ms after server starts)
  try {
    if (serverModuleRef && typeof serverModuleRef.registerRendererInvoker === 'function') {
      serverModuleRef.registerRendererInvoker((action, payload) => {
        try { 
          if (win && !win.isDestroyed() && win.webContents && !win.webContents.isDestroyed()) {
            win.webContents.send('control:perform', { action, payload }); 
          }
        } catch (e) {
          console.error('[Renderer Invoker] Error sending to renderer:', e);
        }
      });
      console.log('[MAIN] Renderer invoker registered for OSC commands');
    }
    // Give the server the app-level abilities the updater needs (version, quit, run installer).
    if (serverModuleRef && typeof serverModuleRef.registerAppControl === 'function') {
      serverModuleRef.registerAppControl({
        /*
         * ProPresenter network password at rest (propresenter-link.js): OS-backed encryption — DPAPI on
         * Windows (the same store Credential Manager uses), Keychain on macOS. Only this Windows user on
         * this machine can decrypt it, so the config file on disk is useless anywhere else.
         */
        secretsAvailable: () => { try { return safeStorage.isEncryptionAvailable(); } catch (_) { return false; } },
        encryptSecret: (plain) => { try { return safeStorage.isEncryptionAvailable() ? safeStorage.encryptString(String(plain)).toString('base64') : null; } catch (_) { return null; } },
        decryptSecret: (b64) => { try { return safeStorage.isEncryptionAvailable() ? safeStorage.decryptString(Buffer.from(String(b64), 'base64')) : null; } catch (_) { return null; } },
        getVersion: () => { try { return app.getVersion(); } catch (_) { return '0.0.0'; } },
        quit: () => { try { app.quit(); } catch (_) {} },
        runInstaller: (installerPath) => {
          // Launch the installer detached, then quit so it can replace the running app.
          try {
            const { spawn } = require('child_process');
            const child = spawn(installerPath, [], { detached: true, stdio: 'ignore', windowsHide: false });
            child.unref();
            setTimeout(() => { try { app.quit(); } catch (_) {} }, 1200);
            return true;
          } catch (e) {
            console.error('[UPDATE] Failed to launch installer:', e && e.message);
            return false;
          }
        },
        /*
         * One downscaled JPEG of the live window, for the phone remote's TV view.
         *
         * capturePage() is a GPU readback of the whole 2160x3840 window, so it is NOT free: the phone
         * asks for frames one at a time (never a fixed timer) and only while the TV view is open, and
         * the resize happens here in the main process so the ~33 MB raw frame never crosses a socket.
         * `captureBusy` drops overlapping requests instead of queueing them — a slow LAN must not be
         * able to stack up captures and stutter the stage screen.
         */
        captureScreen: async (maxWidth, quality) => {
          if (!win || win.isDestroyed() || !win.webContents || win.webContents.isDestroyed()) return null;
          const width = Math.max(240, Math.min(Number(maxWidth) || 540, 4096));
          const q = Math.max(25, Math.min(Number(quality) || 55, 85));

          // FAST PATH: ask the renderer for a frame from its getDisplayMedia self-capture stream
          // (see mirror-stream.js). Misses are normal while the stream warms up (~0.5s) — each one
          // just falls through to capturePage below, so the mirror never blanks.
          if (!mirrorRendererBroken) {
            const fast = await new Promise((resolve) => {
              const id = ++mirrorReqId;
              const timer = setTimeout(() => { mirrorPending.delete(id); resolve(null); }, 450);
              mirrorPending.set(id, { resolve, timer });
              try { win.webContents.send('mirror:frame-request', { id, width, quality: q }); }
              catch (e) { clearTimeout(timer); mirrorPending.delete(id); resolve(null); }
            });
            if (fast && fast.unchanged) return fast;               // nothing painted since last frame
            if (fast && fast.jpeg && fast.jpeg.length) return fast;
          }

          // FALLBACK: main-process capturePage — the slow but always-available path.
          if (captureBusy) return null;
          captureBusy = true;
          try {
            /*
             * capturePage() can never be trusted to come back. On a window the compositor considers
             * occluded (another app in front, minimised) it simply does not resolve — observed hanging
             * indefinitely, and because captureBusy is still held every later request then answers 503
             * forever: the phone's mirror stays dead even after the window is visible again. Race it
             * against a timeout so a hung capture costs one frame instead of the whole feature.
             */
            const img = await Promise.race([
              win.webContents.capturePage(),
              new Promise((resolve) => setTimeout(() => resolve(null), 1500))
            ]);
            if (!img || img.isEmpty()) return null;
            const size = img.getSize();
            const target = Math.min(width, size.width);
            // 'better' costs measurably more CPU per frame than 'good' and is invisible at these sizes.
            const out = target < size.width ? img.resize({ width: target, quality: 'good' }) : img;
            const outSize = out.getSize();
            return { jpeg: out.toJPEG(q), width: outSize.width, height: outSize.height };
          } catch (e) {
            console.error('[REMOTE] captureScreen failed:', e && e.message);
            return null;
          } finally {
            captureBusy = false;
          }
        }
      });
      console.log('[MAIN] App control registered for updater');
    } else {
      console.warn('[MAIN] Server module not available or registerRendererInvoker not found');
    }
  } catch (e) {
    console.error('[MAIN] Failed to register renderer invoker:', e);
  }
  
  // Register log forwarder to send server logs to renderer
  try {
    if (serverModuleRef && typeof serverModuleRef.registerLogForwarder === 'function') {
      serverModuleRef.registerLogForwarder((logEntry) => {
        try {
          if (win && !win.isDestroyed() && win.webContents && !win.webContents.isDestroyed()) {
            win.webContents.send('server-log', logEntry);
          }
        } catch (e) {
          // Ignore forwarding errors
        }
      });
      console.log('[MAIN] Log forwarder registered');
    }
  } catch (e) {
    console.warn('[MAIN] Failed to register log forwarder:', e);
  }
  
  try {
    /*
     * Keep trying the real server before giving up on it. The file:// fallback below is a LAST resort
     * and a bad place to end up — with no http origin every /api call fails, so the app comes up
     * looking oddly empty (default graphics, no content) instead of visibly broken. A slow first boot
     * must not land there, so retry for a few seconds first.
     */
    const firstPort = await awaitServerPort();
    const attempt = (tries, port) => {
      win.loadURL(`http://localhost:${port}/`).catch((err) => {
        // loadURL rejects asynchronously (e.g. server not listening yet / ERR_CONNECTION_REFUSED),
        // which the synchronous catch below cannot see.
        if (win.isDestroyed()) return;
        if (tries > 0) {
          console.warn(`[MAIN] loadURL http://localhost:${port}/ failed (${err && err.message}); retrying, ${tries} left`);
          // Re-resolve each round: a late bind (or a move to 8081) changes the answer.
          setTimeout(() => attempt(tries - 1, resolveServerPort()), 500);
          return;
        }
        console.error('[MAIN] server never answered; falling back to file://index.html — API-backed features will not work:', err && err.message ? err.message : err);
        try { win.loadFile('index.html'); } catch (_) {}
      });
    };
    attempt(12, firstPort);   // ~6s of retries before the degraded fallback
  } catch (_) {
    // Last resort: load file directly (some features depending on the server may not work)
    win.loadFile('index.html');
  }
}

app.whenReady().then(() => {
    ensureDisplayAwake();
    // Re-check every 5 minutes in case the blocker is ever stopped externally.
    setInterval(ensureDisplayAwake, 5 * 60 * 1000);
    createWindow();
});

app.on('window-all-closed', () => {
  stopLlamaServer();
  if (process.platform !== 'darwin') app.quit();
});

app.on('before-quit', () => {
  stopLlamaServer();
});

// Restrict the file/dir IPC handlers to app-owned locations (defense-in-depth; the preload
// allow-list already blocks the renderer from invoking these channels).
function isPathInsideAllowedRoot(targetPath) {
  try {
    const resolved = path.resolve(String(targetPath || ''));
    const roots = [path.resolve(__dirname), path.resolve(app.getPath('userData'))];
    return roots.some((root) => resolved === root || resolved.startsWith(root + path.sep));
  } catch (_) {
    return false;
  }
}

// Handle local file operations
ipcMain.handle('read-directory', async (event, dirPath) => {
  try {
    if (!isPathInsideAllowedRoot(dirPath)) {
      throw new Error('Access denied: path outside allowed roots');
    }
    const files = await fs.readdir(dirPath);
    const fileStats = await Promise.all(
      files.map(async (file) => {
        const filePath = path.join(dirPath, file);
        const stats = await fs.stat(filePath);
        return {
          name: file,
          path: filePath,
          size: stats.size,
          type: path.extname(file).slice(1)
        };
      })
    );
    return fileStats;
  } catch (error) {
    console.error('Error reading directory:', error);
    throw error;
  }
});

ipcMain.handle('read-file', async (event, filePath) => {
  try {
    if (!isPathInsideAllowedRoot(filePath)) {
      throw new Error('Access denied: path outside allowed roots');
    }
    const content = await fs.readFile(filePath);
    return content;
  } catch (error) {
    console.error('Error reading file:', error);
    throw error;
  }
});

// IPC handler for showing About dialog
ipcMain.handle('show-about', async (event) => {
  try {
    const win = BrowserWindow.fromWebContents(event.sender);
    const aboutText = await readTopCommentBlock(path.join(__dirname, 'app.js'));
    // Ask Electron for the version that is ACTUALLY running (it comes from package.json at build
    // time). This used to be a hand-typed "Build:" line in app.js's header comment, which nobody
    // remembered to bump — so About sat on an old number release after release.
    await dialog.showMessageBox(win, {
      type: 'info',
      buttons: ['OK'],
      defaultId: 0,
      title: 'About',
      message: `Bible App ${app.getVersion()}`,
      detail: aboutText || 'Bible App'
    });
    return { success: true };
  } catch (e) {
    try {
      const win = BrowserWindow.fromWebContents(event.sender);
      await dialog.showMessageBox(win, { 
        type: 'info', 
        buttons: ['OK'], 
        title: 'About', 
        message: 'Bible App' 
      });
      return { success: true };
    } catch (e2) {
      return { success: false, error: e2.message };
    }
  }
});

// IPC handler for closing the app
ipcMain.handle('close-app', async (event) => {
  try {
    app.quit();
    return { success: true };
  } catch (e) {
    return { success: false, error: e.message };
  }
});


// ---------- Menu & Helpers ----------
function setupAppMenu(win) {
  const fileSubmenu = [
    {
      label: 'Content Manager',
      click: async () => {
        try {
          const port = resolveServerPort();
          await win.loadURL(`http://localhost:${port}/content-manager.html`);
        } catch (e) {
          console.error('Failed to open content manager:', e);
        }
      }
    },
    {
      label: 'Settings',
      click: async () => {
        try {
          const port = resolveServerPort();
          await win.loadURL(`http://localhost:${port}/settings.html`);
        } catch (e) {
          console.error('Failed to open settings:', e);
        }
      }
    },
    {
      label: 'Log Viewer',
      click: async () => {
        try {
          const port = resolveServerPort();
          await win.loadURL(`http://localhost:${port}/log-viewer.html`);
        } catch (e) {
          console.error('Failed to open log viewer:', e);
        }
      }
    },
    { type: 'separator' },
    { role: 'quit', label: 'Exit' }
  ];

  const helpSubmenu = [
    {
      label: 'Toggle Developer Tools',
      accelerator: 'F12',
      click: () => {
        if (win.webContents.isDevToolsOpened()) {
          win.webContents.closeDevTools();
        } else {
          win.webContents.openDevTools();
        }
      }
    },
    { type: 'separator' },
    {
      label: 'About',
      click: async () => {
        try {
          const aboutText = await readTopCommentBlock(path.join(__dirname, 'app.js'));
          await dialog.showMessageBox(win, {
            type: 'info',
            buttons: ['OK'],
            defaultId: 0,
            title: 'About',
            message: 'Bible App',
            detail: aboutText || 'Bible App'
          });
        } catch (e) {
          await dialog.showMessageBox(win, { type: 'info', buttons: ['OK'], title: 'About', message: 'Bible App' });
        }
      }
    }
  ];

  const template = [
    { label: 'File', submenu: fileSubmenu },
    { role: 'editMenu' },
    { role: 'viewMenu' },
    { role: 'windowMenu' },
    { label: 'Help', role: 'help', submenu: helpSubmenu }
  ];
  const menu = Menu.buildFromTemplate(template);
  Menu.setApplicationMenu(menu);
}

async function readTopCommentBlock(filePath) {
  try {
    const text = await fs.readFile(filePath, 'utf-8');
    const m = text.match(/\/\*[\s\S]*?\*\//);
    return m ? m[0].replace(/^\/\*+\s*|\s*\*+\/$/g, '').trim() : '';
  } catch (_) {
    return '';
  }
}