/**
 * ╔══════════════════════════════════════════════════════════════════════╗
 * ║               CHAHUADEV HUB — Electron Main Process                 ║
 * ║              Official App Distribution Center (Desktop)             ║
 * ╚══════════════════════════════════════════════════════════════════════╝
 *
 * @author    Chahuadev
 * @license   NON-COMMERCIAL & ACCEPTABLE USE ONLY.
 *            Strictly prohibited for sale or malicious activities.
 *            See LICENSE.md for full terms.
 */

'use strict';

const { app, BrowserWindow, ipcMain, shell, session, Menu } = require('electron');
const { autoUpdater } = require('electron-updater');
const path         = require('path');
const fs           = require('fs');
const os           = require('os');
const https        = require('https');
const http         = require('http');
const { spawn, exec } = require('child_process');
const { URL } = require('url');
const SecurityCore = require('./security/security-core.js');

// Ignore dev flags in packaged builds so end users cannot force dev mode.
if (app.isPackaged) {
  process.argv = process.argv.filter(arg => arg !== '--dev' && arg !== '--dev-mode');
}

// ── Constants ────────────────────────────────────────────────────────────────
const HF_AUTHOR      = 'chahuadev';
const HF_REPO        = 'chahuadev/chahuadev-framework-binaries';
const HF_API_URL     = `https://huggingface.co/api/datasets/${HF_REPO}/tree/main`;
const HF_COMMITS_URL  = `https://huggingface.co/api/datasets/${HF_REPO}/commits/main`;
const R2_CDN_BASE     = 'https://r2.chahuadev.com';
const R2_CATALOG_URL  = 'https://r2.chahuadev.com/catalog.json';
const APP_CATALOG_ID  = 'chahuadev-hub';
const GITHUB_CATALOG_URL = 'https://raw.githubusercontent.com/toyspata00/chahuadev-hub/main/catalog.json';
const HF_DATASETS_API = `https://huggingface.co/api/datasets?author=${HF_AUTHOR}&full=true`;
const HF_MODELS_API   = `https://huggingface.co/api/models?author=${HF_AUTHOR}&full=true`;
const HF_SPACES_API   = `https://huggingface.co/api/spaces?author=${HF_AUTHOR}&full=true`;
const DOWNLOAD_DIR   = path.join(os.homedir(), 'Downloads', 'ChahuadevHub');
const APP_BASE_DIR   = app.isPackaged
  ? (process.env.PORTABLE_EXECUTABLE_DIR || path.dirname(process.execPath))
  : __dirname;
const HF_SANDBOX_DIR = path.join(APP_BASE_DIR, '.hf-sandbox-cache');

// ── npm Registry Constants ────────────────────────────────────────────────────
const NPM_ORG          = 'chahuadev';
const NPM_ORG_PKG_URL  = `https://registry.npmjs.org/-/org/${NPM_ORG}/package`;
const NPM_REG_BASE     = 'https://registry.npmjs.org';
const NPM_DL_BASE      = 'https://api.npmjs.org/downloads/point/last-month';

// ── Cache System (ป้องกันคนรัวปุ่ม) ─────────────────────────────────────────
let cachedChangelog    = null;
let lastChangelogFetch = 0;
const CACHE_COOLDOWN   = 5 * 60 * 1000; // 5 นาที
const HF_TREE_STALE_MS = 5 * 60 * 1000;
const HF_PREVIEW_MAX_BYTES = 256 * 1024;

// npm cache
let cachedNpmPackages    = null;
let lastNpmFetch         = 0;

// Hugging Face API cache (keyed by endpoint) with in-flight de-duplication
const hfApiCache = new Map();
const hfPendingRequests = new Map();
const hfRepoTreeCache = new Map();
const hfRepoCommitHeadCache = new Map();
const hfRepoFileCacheMeta = new Map();

const SKIP_FILES = new Set([
  '.gitattributes', 'README.md',
  'chahuadev-framework-binaries.png', 'emoji-cleaner-app.png'
]);

// Allowed npm packages for self-update / install (whitelist — renderer cannot override)
const NPM_PKG_WHITELIST = new Set([
  '@chahuadev/chahuadev-hub-app',
  '@chahuadev/dev-launcher',
  '@chahuadev/junk-sweeper-app',
  '@chahuadev/emoji-cleaner-app',
  '@chahuadev/framework'
]);

const isDev = !app.isPackaged && process.argv.includes('--dev');
const UPDATE_CHANNEL = ((process.env.APP_UPDATE_CHANNEL || process.env.UPDATE_CHANNEL || 'stable').toLowerCase() === 'beta') ? 'beta' : 'stable';
const UPDATE_BASE_URL = 'https://r2.chahuadev.com';
let updaterInitialized = false;
let updaterState = {
  lastCheckedAt: null,
  lastResult: 'idle',
  lastError: null
};
const security = new SecurityCore();

function configureUpdaterFeed() {
  const feedUrl = `${UPDATE_BASE_URL}/`;
  autoUpdater.setFeedURL({
    provider: 'generic',
    url: feedUrl
  });
  autoUpdater.allowPrerelease = UPDATE_CHANNEL === 'beta';
  autoUpdater.allowDowngrade = true;
  autoUpdater.channel = UPDATE_CHANNEL;
  console.log(`[Updater] Channel: ${UPDATE_CHANNEL} | Feed: ${feedUrl}`);
}

async function checkForUpdatesNow() {
  updaterState.lastCheckedAt = new Date().toISOString();
  try {
    const result = await autoUpdater.checkForUpdates();
    const version = result && result.updateInfo && result.updateInfo.version ? result.updateInfo.version : null;
    updaterState.lastResult = version ? 'update-available' : 'no-update';
    updaterState.lastError = null;
    return {
      ok: true,
      channel: UPDATE_CHANNEL,
      updateAvailable: Boolean(version),
      version
    };
  } catch (error) {
    updaterState.lastResult = 'error';
    updaterState.lastError = error && error.message ? error.message : String(error);
    return {
      ok: false,
      channel: UPDATE_CHANNEL,
      error: updaterState.lastError
    };
  }
}

function initAutoUpdater() {
  if (!app.isPackaged || isDev) return;
  configureUpdaterFeed();
  autoUpdater.autoDownload = true;
  autoUpdater.autoInstallOnAppQuit = true;
  autoUpdater.logger = console;
  autoUpdater.on('error', (e) => {
    updaterState.lastResult = 'error';
    updaterState.lastError = e && e.message ? e.message : String(e);
    console.warn('[Updater] Error:', updaterState.lastError);
  });
  autoUpdater.on('update-available', () => {
    updaterState.lastResult = 'update-available';
    updaterState.lastError = null;
  });
  autoUpdater.on('update-not-available', () => {
    updaterState.lastResult = 'no-update';
    updaterState.lastError = null;
  });
  autoUpdater.on('update-downloaded', (info) => {
    updaterState.lastResult = 'downloaded';
    const r = require('electron').dialog.showMessageBoxSync({
      type: 'info',
      buttons: ['Restart now', 'Later'],
      defaultId: 0,
      cancelId: 1,
      title: 'Update ready',
      message: `Version ${info && info.version ? info.version : 'new'} is ready to install.`
    });
    if (r === 0) autoUpdater.quitAndInstall();
  });
  setTimeout(() => autoUpdater.checkForUpdates().catch(() => {}), 12000);
  setInterval(() => autoUpdater.checkForUpdates().catch(() => {}), 6 * 60 * 60 * 1000);
  updaterInitialized = true;
}

function createDevMenuTemplate() {
  return [
    {
      label: 'File',
      submenu: [
        { role: 'close' },
        { type: 'separator' },
        { role: process.platform === 'darwin' ? 'hide' : 'quit' }
      ]
    },
    {
      label: 'Edit',
      submenu: [
        { role: 'undo' }, { role: 'redo' },
        { type: 'separator' },
        { role: 'cut' }, { role: 'copy' }, { role: 'paste' },
        { role: 'selectAll' }
      ]
    },
    {
      label: 'View',
      submenu: [
        { role: 'reload' },
        { role: 'forceReload' },
        { type: 'separator' },
        { role: 'resetZoom' },
        { role: 'zoomIn' },
        { role: 'zoomOut' },
        { type: 'separator' },
        { role: 'togglefullscreen' }
      ]
    },
    {
      label: 'Window',
      submenu: [
        { role: 'minimize' },
        { role: 'zoom' },
        { role: 'close' }
      ]
    },
    {
      label: 'Help',
      submenu: [
        {
          label: 'Chahuadev Website',
          click: () => shell.openExternal('https://chahuadev.com/')
        }
      ]
    },
    {
      label: 'Dev',
      submenu: [
        { role: 'toggleDevTools' },
        { role: 'reload' },
        { role: 'forceReload' }
      ]
    }
  ];
}

function applyProductionWindowHardening(win) {
  if (isDev || !win || win.isDestroyed()) return;

  win.webContents.on('before-input-event', (event, input) => {
    const key = (input.key || '').toLowerCase();
    const blockedShortcut =
      key === 'f12' ||
      ((input.control || input.meta) && input.shift && (key === 'i' || key === 'j' || key === 'c'));

    if (blockedShortcut) {
      event.preventDefault();
    }
  });

  win.webContents.on('devtools-opened', () => {
    if (!win.webContents.isDestroyed()) {
      win.webContents.closeDevTools();
    }
  });
}

// ── Security Init ────────────────────────────────────────────────────────────────────
function initSecurity() {
  security.applySecurityConfig();  // Layer 5b: enforce strict CSP from main process (survives HTML tampering)
  security.applyStrictCSP(session.defaultSession, isDev);  if (!isDev) {
    const ok = security.validateChecksums();
    if (!ok) {
      console.error('[Security] CRITICAL: Integrity check failed.');
      // Don’t hard-exit on first run (checksums may not exist yet)
    }
    console.log('[Security] Production mode active.');
  } else {
    console.log('[Security] Dev mode — security checks relaxed.');
  }
}

// ── Windows ───────────────────────────────────────────────────────────────────
let mainWindow   = null;
let splashWindow = null;

// ── HTTP Helper (follows redirects) ──────────────────────────────────────────
function fetchJSON(urlStr, redirectCount = 0) {
  return new Promise((resolve, reject) => {
    if (redirectCount > 10) return reject(new Error('Too many redirects'));
    let parsed;
    try { parsed = new URL(urlStr); } catch (e) { return reject(e); }
    const mod = parsed.protocol === 'https:' ? https : http;
    const req = mod.get(urlStr, {
      headers: { 'User-Agent': 'ChahuadevHub/1.0.0 (Electron)' }
    }, (res) => {
      if (res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
        res.resume();
        const nextUrl = new URL(res.headers.location, urlStr).toString();
        fetchJSON(nextUrl, redirectCount + 1).then(resolve).catch(reject);
        return;
      }
      if (res.statusCode !== 200) {
        res.resume();
        return reject(new Error(`HTTP ${res.statusCode} — ${urlStr}`));
      }
      let data = '';
      res.on('data', chunk => { data += chunk; });
      res.on('end', () => {
        try { resolve(JSON.parse(data)); } catch (e) { reject(e); }
      });
      res.on('error', reject);
    });
    req.on('error', reject);
    req.setTimeout(20000, () => { req.destroy(new Error('Request timeout')); });
  });
}

async function fetchWithCooldownCache(cacheKey, fetcher) {
  const now = Date.now();
  const cached = hfApiCache.get(cacheKey);
  if (cached && (now - cached.ts < CACHE_COOLDOWN)) {
    return cached.data;
  }

  if (hfPendingRequests.has(cacheKey)) {
    return hfPendingRequests.get(cacheKey);
  }

  const pending = (async () => {
    const data = await fetcher();
    hfApiCache.set(cacheKey, { ts: Date.now(), data });
    return data;
  })();

  hfPendingRequests.set(cacheKey, pending);
  try {
    return await pending;
  } finally {
    hfPendingRequests.delete(cacheKey);
  }
}

function normalizeRepoPath(input) {
  const raw = String(input || '').replace(/\\/g, '/').trim();
  if (!raw) return '';
  const cleaned = raw
    .split('/')
    .filter(Boolean)
    .filter(seg => seg !== '.' && seg !== '..')
    .join('/');
  return cleaned;
}

function getRepoTypeSegment(repoType) {
  const t = String(repoType || '').toLowerCase();
  if (t === 'dataset') return 'datasets';
  if (t === 'space') return 'spaces';
  return 'models';
}

function buildRepoTreeApiUrl(repoId, repoType, repoPath = '', expand = false) {
  const typeSegment = getRepoTypeSegment(repoType);
  const normalizedPath = normalizeRepoPath(repoPath);
  const encodedPath = normalizedPath
    ? '/' + normalizedPath.split('/').map(encodeURIComponent).join('/')
    : '';
  const suffix = expand ? '?expand=true' : '';
  return `https://huggingface.co/api/${typeSegment}/${repoId}/tree/main${encodedPath}${suffix}`;
}

function buildRepoRawFileUrl(repoId, repoType, repoPath) {
  const normalizedPath = normalizeRepoPath(repoPath);
  const encodedPath = normalizedPath.split('/').map(encodeURIComponent).join('/');
  const prefix = repoType === 'dataset' ? 'datasets/' : repoType === 'space' ? 'spaces/' : '';
  return `https://huggingface.co/${prefix}${repoId}/resolve/main/${encodedPath}?download=true`;
}

function getRepoCacheRoot(repoId, repoType) {
  const safeRepo = String(repoId || '').replace(/[^a-zA-Z0-9._\/-]/g, '_');
  const root = path.join(HF_SANDBOX_DIR, getRepoTypeSegment(repoType), safeRepo);
  fs.mkdirSync(root, { recursive: true });
  return root;
}

function resolveSafeRepoLocalPath(repoId, repoType, repoPath) {
  const repoRoot = getRepoCacheRoot(repoId, repoType);
  const parts = normalizeRepoPath(repoPath).split('/').filter(Boolean);
  const target = path.resolve(repoRoot, ...parts);
  const safeRoot = path.resolve(repoRoot);
  if (!target.startsWith(safeRoot)) {
    throw new Error('Invalid file path');
  }
  fs.mkdirSync(path.dirname(target), { recursive: true });
  return target;
}

async function getLatestRepoCommitHead(repoId, repoType) {
  const key = `${repoType}:${repoId}`;
  const now = Date.now();
  const cached = hfRepoCommitHeadCache.get(key);
  if (cached && (now - cached.checkedAt < HF_TREE_STALE_MS)) {
    return cached;
  }

  const url = `https://huggingface.co/api/${getRepoTypeSegment(repoType)}/${repoId}/commits/main`;
  const commits = await fetchJSON(url);
  const head = Array.isArray(commits) && commits[0] ? commits[0] : {};
  const value = {
    id: String(head.id || head.sha || ''),
    date: String(head.date || head.createdAt || ''),
    checkedAt: now
  };
  hfRepoCommitHeadCache.set(key, value);
  return value;
}

async function fetchRepoTreeSmart(repoId, repoType, options = {}) {
  const normalizedPath = normalizeRepoPath(options.path || '');
  const expand = !!options.expand;
  const force = !!options.force;
  const cacheKey = `${repoType}:${repoId}:${normalizedPath}:${expand ? 'expand' : 'flat'}`;
  const now = Date.now();
  const cached = hfRepoTreeCache.get(cacheKey);

  if (cached && !force && (now - cached.checkedAt < HF_TREE_STALE_MS)) {
    return cached.entries;
  }

  let head = null;
  try {
    head = await getLatestRepoCommitHead(repoId, repoType);
  } catch {
    // If commit endpoint fails but we have cached tree, serve cache.
    if (cached && !force) {
      cached.checkedAt = now;
      return cached.entries;
    }
  }

  if (cached && !force && head && head.id && cached.commitId && head.id === cached.commitId) {
    cached.checkedAt = now;
    return cached.entries;
  }

  const url = buildRepoTreeApiUrl(repoId, repoType, normalizedPath, expand);
  const entries = await fetchJSON(url);
  const normalizedEntries = Array.isArray(entries) ? entries : [];
  hfRepoTreeCache.set(cacheKey, {
    entries: normalizedEntries,
    checkedAt: now,
    commitId: head && head.id ? head.id : (cached && cached.commitId ? cached.commitId : ''),
    path: normalizedPath,
    expand
  });
  return normalizedEntries;
}

function detectLanguageFromPath(filePath) {
  const ext = path.extname(String(filePath || '')).toLowerCase();
  const map = {
    '.js': 'javascript', '.cjs': 'javascript', '.mjs': 'javascript',
    '.ts': 'typescript', '.tsx': 'typescript', '.jsx': 'javascript',
    '.json': 'json', '.md': 'markdown', '.txt': 'plaintext',
    '.html': 'html', '.css': 'css', '.scss': 'scss',
    '.py': 'python', '.java': 'java', '.go': 'go',
    '.yml': 'yaml', '.yaml': 'yaml', '.xml': 'xml',
    '.sh': 'shell', '.bat': 'bat', '.ps1': 'powershell',
    '.rs': 'rust', '.cpp': 'cpp', '.c': 'c'
  };
  return map[ext] || 'plaintext';
}

function isLikelyTextBuffer(buffer) {
  if (!buffer || buffer.length === 0) return true;
  const sample = buffer.subarray(0, Math.min(buffer.length, 4096));
  for (let i = 0; i < sample.length; i++) {
    if (sample[i] === 0) return false;
  }
  return true;
}

async function cacheRepoFileLocally(repoId, repoType, repoPath) {
  const normalizedPath = normalizeRepoPath(repoPath);
  if (!normalizedPath) throw new Error('Missing repo file path');

  const metaKey = `${repoType}:${repoId}:${normalizedPath}`;
  const head = await getLatestRepoCommitHead(repoId, repoType).catch(() => null);
  const localPath = resolveSafeRepoLocalPath(repoId, repoType, normalizedPath);
  const prevMeta = hfRepoFileCacheMeta.get(metaKey);

  if (
    prevMeta &&
    fs.existsSync(prevMeta.localPath) &&
    head &&
    head.id &&
    prevMeta.commitId === head.id
  ) {
    return { localPath: prevMeta.localPath, commitId: prevMeta.commitId };
  }

  const rawUrl = buildRepoRawFileUrl(repoId, repoType, normalizedPath);
  await downloadRaw(rawUrl, localPath);
  try {
    fs.chmodSync(localPath, 0o444);
  } catch {
    // Best effort only; some environments may not support chmod semantics.
  }

  const commitId = head && head.id ? head.id : (prevMeta && prevMeta.commitId ? prevMeta.commitId : '');
  hfRepoFileCacheMeta.set(metaKey, { localPath, commitId, updatedAt: Date.now() });
  return { localPath, commitId };
}

function openFileInBestEditor(targetPath) {
  return new Promise((resolve) => {
    const safePath = String(targetPath || '');
    if (!safePath) return resolve('not-found');

    const quoted = safePath.replace(/"/g, '\\"');
    exec(`code -g "${quoted}"`, { windowsHide: true }, (codeErr) => {
      if (!codeErr) return resolve('ok-vscode');

      const npCandidates = [
        process.env.NotepadPlusPlusPath || '',
        'C:\\Program Files\\Notepad++\\notepad++.exe',
        'C:\\Program Files (x86)\\Notepad++\\notepad++.exe'
      ].filter(Boolean);

      const npPath = npCandidates.find(p => fs.existsSync(p));
      if (npPath) {
        const child = spawn(npPath, [safePath], { detached: true, stdio: 'ignore', windowsHide: true });
        child.unref();
        return resolve('ok-notepadpp');
      }

      shell.openPath(safePath).then(() => resolve('ok-default')).catch(() => resolve('error'));
    });
  });
}

// ── Semver comparison helper ──────────────────────────────────────────────────
function semverGt(a, b) {
  const pa = String(a || '0').split('.').map(Number);
  const pb = String(b || '0').split('.').map(Number);
  for (let i = 0; i < 3; i++) {
    const na = pa[i] || 0, nb = pb[i] || 0;
    if (na > nb) return true;
    if (na < nb) return false;
  }
  return false;
}

function mapPlatformToCatalogOs(platform) {
  if (platform === 'win32') return 'Windows';
  if (platform === 'linux') return 'Linux';
  if (platform === 'darwin') return 'macOS';
  return 'Unknown';
}

function findCatalogEntry(catalog) {
  const files = catalog && Array.isArray(catalog.files) ? catalog.files : [];
  const platformOs = mapPlatformToCatalogOs(process.platform);
  const exact = files.find((f) => f && f.id === APP_CATALOG_ID && f.os === platformOs);
  if (exact) return exact;
  return files.find((f) => f && f.id === APP_CATALOG_ID) || null;
}

// ── Raw file downloader used by hot-patch ─────────────────────────────────────
function downloadRaw(urlStr, destPath, redirectCount = 0) {
  return new Promise((resolve, reject) => {
    if (redirectCount > 10) return reject(new Error('Too many redirects'));
    let parsed;
    try { parsed = new URL(urlStr); } catch (e) { return reject(e); }
    const mod = parsed.protocol === 'https:' ? https : http;
    const req = mod.get(urlStr, {
      headers: { 'User-Agent': 'ChahuadevHub/1.0.0 (Electron)' }
    }, (res) => {
      if (res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
        res.resume();
        const nextUrl = new URL(res.headers.location, urlStr).toString();
        downloadRaw(nextUrl, destPath, redirectCount + 1).then(resolve).catch(reject);
        return;
      }
      if (res.statusCode !== 200) { res.resume(); return reject(new Error(`HTTP ${res.statusCode}`)); }
      fs.mkdirSync(path.dirname(destPath), { recursive: true });
      const ws = fs.createWriteStream(destPath);
      res.pipe(ws);
      ws.on('finish', () => ws.close(() => resolve(destPath)));
      ws.on('error', reject);
    });
    req.on('error', reject);
    req.setTimeout(30000, () => req.destroy(new Error('Timeout')));
  });
}

// ── Splash Window ─────────────────────────────────────────────────────────────
function createSplashWindow() {
  splashWindow = new BrowserWindow({
    width: 520,
    height: 340,
    frame: false,
    resizable: false,
    alwaysOnTop: true,
    skipTaskbar: true,
    center: true,
    backgroundColor: '#09090f',
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      nodeIntegration: false,
      contextIsolation: true,
      sandbox: true
    }
  });
  splashWindow.loadFile(path.join(__dirname, 'splash.html'));
  splashWindow.webContents.on('will-navigate', (e) => e.preventDefault());
}

// ── Main Window ───────────────────────────────────────────────────────────────
function createMainWindow() {
  mainWindow = new BrowserWindow({
    width: 1100,
    height: 740,
    minWidth: 900,
    minHeight: 580,
    show: false,
    backgroundColor: '#09090f',
    icon: path.join(__dirname, 'icons', 'icon.png'),
    autoHideMenuBar: !isDev,
    webPreferences: {
      preload: path.join(__dirname, 'preload.js'),
      nodeIntegration: false,
      contextIsolation: true,
      sandbox: true
    }
  });

  mainWindow.loadFile(path.join(__dirname, 'index.html'));
  mainWindow.setMenuBarVisibility(isDev);

  // Block external navigation
  mainWindow.webContents.on('will-navigate', (e) => e.preventDefault());
  mainWindow.webContents.setWindowOpenHandler(() => ({ action: 'deny' }));

  // Security: DevTools lockdown + navigation guard
  security.applyDevToolsLockdown(mainWindow, isDev);
  applyProductionWindowHardening(mainWindow);

  mainWindow.once('ready-to-show', () => {
    const delay = isDev ? 120 : 350;
    setTimeout(() => {
      if (splashWindow && !splashWindow.isDestroyed()) {
        splashWindow.close();
        splashWindow = null;
      }
      if (mainWindow && !mainWindow.isDestroyed()) {
        mainWindow.show();
        mainWindow.focus();
        if (isDev) mainWindow.webContents.openDevTools();
      }
    }, delay);
  });

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

// ── App lifecycle ─────────────────────────────────────────────────────────────
app.whenReady().then(() => {
  createSplashWindow();
  initSecurity();
  initAutoUpdater();
  if (isDev) {
    Menu.setApplicationMenu(Menu.buildFromTemplate(createDevMenuTemplate()));
  } else {
    Menu.setApplicationMenu(null);
  }
  fs.mkdirSync(DOWNLOAD_DIR, { recursive: true });
  createMainWindow();

  app.on('activate', () => {
    if (BrowserWindow.getAllWindows().length === 0) createMainWindow();
  });
});

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

// ════════════════════════════════════════════════════════════════════════════
// IPC Handlers
// ════════════════════════════════════════════════════════════════════════════

// Return download directory path
ipcMain.handle('get-download-dir', () => DOWNLOAD_DIR);

// Expose isDev flag to renderer (for hiding dev-only features)
ipcMain.handle('get-is-dev', () => isDev);

// Fetch file list from catalog.json (GitHub primary, R2 + local fallback)
ipcMain.handle('fetch-files', async () => {
  const parseFiles = (data) => {
    if (Array.isArray(data)) return data;
    if (data && Array.isArray(data.files)) return data.files;
    return [];
  };

  const sources = [
    GITHUB_CATALOG_URL,
    R2_CATALOG_URL,
  ];

  for (const src of sources) {
    try {
      const data = await fetchWithCooldownCache(src, () => fetchJSON(src));
      return { files: parseFiles(data) };
    } catch (error) {
      console.warn('[catalog] Remote fetch failed:', src, error.message);
    }
  }

  try {
    const localPath = path.join(__dirname, 'catalog.json');
    if (fs.existsSync(localPath)) {
      const raw = fs.readFileSync(localPath, 'utf8');
      const data = JSON.parse(raw);
      return { files: parseFiles(data) };
    }
  } catch (localErr) {
    console.error('[catalog] Local fallback failed:', localErr.message);
  }

  return { files: [] };
});

// Fetch commit changelog — with cache + cooldown to block API spam
ipcMain.handle('fetch-changelog', async () => {
  const now = Date.now();

  if (cachedChangelog && (now - lastChangelogFetch < CACHE_COOLDOWN)) {
    console.log('[Cache] Returning cached changelog');
    return cachedChangelog;
  }

  try {
    const endpoints = [
      [HF_DATASETS_API, 'dataset'],
      [HF_MODELS_API,   'model'],
      [HF_SPACES_API,   'space']
    ];

    let allRepos = [];
    for (const [url, rtype] of endpoints) {
      try {
        const data = await fetchJSON(url);
        for (const r of data) allRepos.push({ repoId: r.id || r.modelId, type: rtype });
      } catch (_) { }
    }

    const commitPromises = allRepos.map(async ({ repoId, type }) => {
      const commitUrl = `https://huggingface.co/api/${type}s/${repoId}/commits/main`;
      try {
        const commits = await fetchJSON(commitUrl);
        return commits.map(c => {
          const shortRepo = repoId.split('/').pop();
          c.title = `[${shortRepo}] ${c.title || c.message || '—'}`;
          return c;
        });
      } catch (_) { return []; }
    });

    const results = await Promise.all(commitPromises);
    let allCommits = [];
    results.forEach(repoCommits => { allCommits = allCommits.concat(repoCommits); });
    allCommits.sort((a, b) => new Date(b.date) - new Date(a.date));
    const finalData = allCommits.slice(0, 50);

    cachedChangelog    = finalData;
    lastChangelogFetch = now;
    return finalData;

  } catch (err) {
    console.error('Changelog fetch error:', err);
    throw err;
  }
});

// Fetch all repos (datasets + models + spaces) for Explorer panel
ipcMain.handle('fetch-all-repos', async () => {
  const [datasetsRaw, modelsRaw, spacesRaw] = await Promise.all([
    fetchWithCooldownCache(HF_DATASETS_API, () => fetchJSON(HF_DATASETS_API)).catch(() => []),
    fetchWithCooldownCache(HF_MODELS_API, () => fetchJSON(HF_MODELS_API)).catch(()   => []),
    fetchWithCooldownCache(HF_SPACES_API, () => fetchJSON(HF_SPACES_API)).catch(()   => []),
  ]);

  const sortByDate = arr => [...arr].sort((a, b) => {
    const da = a.lastModified || a.updatedAt || '';
    const db = b.lastModified || b.updatedAt || '';
    return db.localeCompare(da);
  });

  return {
    datasets: sortByDate(Array.isArray(datasetsRaw) ? datasetsRaw : []),
    models:   sortByDate(Array.isArray(modelsRaw)   ? modelsRaw   : []),
    spaces:   sortByDate(Array.isArray(spacesRaw)   ? spacesRaw   : []),
  };
});

// Fetch commits for a specific repo
ipcMain.handle('fetch-repo-commits', async (_, repoId, repoType) => {
  const url = `https://huggingface.co/api/${repoType}s/${repoId}/commits/main`;
  return await fetchWithCooldownCache(url, () => fetchJSON(url));
});

// Fetch file tree for a specific repo
ipcMain.handle('fetch-repo-tree', async (_, repoId, repoType, options = {}) => {
  return fetchRepoTreeSmart(repoId, repoType, options);
});

ipcMain.handle('fetch-repo-file', async (_, repoId, repoType, repoPath) => {
  try {
    const normalizedPath = normalizeRepoPath(repoPath);
    if (!normalizedPath) {
      return { ok: false, error: 'Missing file path' };
    }

    const { localPath } = await cacheRepoFileLocally(repoId, repoType, normalizedPath);
    const stat = fs.statSync(localPath);
    const isTooLarge = stat.size > HF_PREVIEW_MAX_BYTES;
    const previewSize = Math.min(stat.size, HF_PREVIEW_MAX_BYTES);
    const buffer = Buffer.alloc(previewSize);
    const fd = fs.openSync(localPath, 'r');
    try {
      fs.readSync(fd, buffer, 0, previewSize, 0);
    } finally {
      fs.closeSync(fd);
    }
    const isText = isLikelyTextBuffer(buffer);
    let content = '';

    if (isText) {
      content = buffer.toString('utf8');
    }

    return {
      ok: true,
      path: normalizedPath,
      localPath,
      isText,
      size: stat.size,
      truncated: isTooLarge,
      language: detectLanguageFromPath(normalizedPath),
      content
    };
  } catch (error) {
    return { ok: false, error: error && error.message ? error.message : String(error) };
  }
});

ipcMain.handle('open-repo-file-editor', async (_, repoId, repoType, repoPath) => {
  try {
    const normalizedPath = normalizeRepoPath(repoPath);
    if (!normalizedPath) return { ok: false, error: 'Missing file path' };
    const { localPath } = await cacheRepoFileLocally(repoId, repoType, normalizedPath);
    const result = await openFileInBestEditor(localPath);
    return { ok: result !== 'error', mode: result, localPath };
  } catch (error) {
    return { ok: false, error: error && error.message ? error.message : String(error) };
  }
});

// Fetch dashboard stats: datasets + models + spaces counts, total downloads, recent activity
ipcMain.handle('fetch-dashboard', async () => {
  const endpoints = [
    [HF_DATASETS_API, 'dataset'],
    [HF_MODELS_API,   'model'],
    [HF_SPACES_API,   'space']
  ];
  const stats   = { datasets: 0, models: 0, spaces: 0, totalDownloads: 0 };
  const activity = [];

  for (const [url, rtype] of endpoints) {
    try {
      const data = await fetchWithCooldownCache(url, () => fetchJSON(url));
      if (!Array.isArray(data)) continue;
      if (rtype === 'dataset') stats.datasets = data.length;
      if (rtype === 'model')   stats.models   = data.length;
      if (rtype === 'space')   stats.spaces   = data.length;
      for (const r of data) {
        const dl = r.downloads || r.downloadsAllTime || 0;
        stats.totalDownloads += Number(dl) || 0;
        const id      = r.id || r.modelId || '';
        const updated = r.lastModified || r.updatedAt || '';
        if (id && updated) activity.push({ id, type: rtype, updated, private: !!r.private });
      }
    } catch (_) { /* skip */ }
  }

  activity.sort((a, b) => b.updated.localeCompare(a.updated));
  return { stats, activity: activity.slice(0, 20) };
});

// ── npm Packages ─────────────────────────────────────────────────────────────
// Fetch all packages in the @chahuadev npm org with metadata + monthly downloads
ipcMain.handle('fetch-npm-packages', async () => {
  const now = Date.now();
  if (cachedNpmPackages && (now - lastNpmFetch < CACHE_COOLDOWN)) {
    return cachedNpmPackages;
  }

  try {
    // 1. Get list of packages in the org
    const pkgMap = await fetchJSON(NPM_ORG_PKG_URL);
    const names  = Object.keys(pkgMap || {});

    // 2. Fetch metadata + downloads for each package in parallel
    const results = await Promise.all(
      names.map(async (name) => {
        const [meta, dlData] = await Promise.all([
          fetchJSON(`${NPM_REG_BASE}/${encodeURIComponent(name)}`).catch(() => null),
          fetchJSON(`${NPM_DL_BASE}/${encodeURIComponent(name)}`).catch(() => null),
        ]);

        const latest  = meta?.['dist-tags']?.latest || '';
        const verData = meta?.versions?.[latest] || {};
        const timeMap = meta?.time || {};
        const versionTimeRows = Object.entries(timeMap)
          .filter(([v]) => v !== 'created' && v !== 'modified')
          .sort((a, b) => String(b[1] || '').localeCompare(String(a[1] || '')));
        const repositoryUrl = typeof verData.repository === 'string'
          ? verData.repository
          : (verData.repository && verData.repository.url ? verData.repository.url : '');
        const readmeRaw = typeof meta?.readme === 'string' ? meta.readme : '';
        const readmeExcerpt = readmeRaw.slice(0, 12000);
        return {
          name,
          version:     latest,
          description: verData.description || meta?.description || '',
          keywords:    verData.keywords    || [],
          homepage:    verData.homepage    || `https://www.npmjs.com/package/${encodeURIComponent(name)}`,
          license:     verData.license     || '',
          updatedAt:   meta?.time?.[latest] || '',
          downloads:   dlData?.downloads   || 0,
          versionsCount: Object.keys(meta?.versions || {}).length,
          recentVersions: versionTimeRows.slice(0, 12).map(([version, date]) => ({ version, date })),
          repositoryUrl,
          npmUrl: `https://www.npmjs.com/package/${encodeURIComponent(name)}`,
          readmeExcerpt,
        };
      })
    );

    // Sort by downloads descending
    results.sort((a, b) => b.downloads - a.downloads);

    cachedNpmPackages = results;
    lastNpmFetch      = now;
    return results;
  } catch (err) {
    console.error('[npm] fetch-npm-packages error:', err);
    throw err;
  }
});

// Check if a downloaded file already exists on disk
ipcMain.handle('check-file-exists', (_, filePath) => {
  const destPath = path.join(DOWNLOAD_DIR, filePath);
  return fs.existsSync(destPath);
});

// ── Update detection: single downloads-meta.json inside app userData ─────────
// Stored in %APPDATA%/Chahuadev-Hub/downloads-meta.json  (never in user Downloads)
// Schema: { "Junk-Sweeper.exe": { version, releaseDate }, ... }
const DOWNLOADS_META_PATH = path.join(app.getPath('userData'), 'downloads-meta.json');

function readDownloadsMeta() {
  try {
    if (!fs.existsSync(DOWNLOADS_META_PATH)) return {};
    return JSON.parse(fs.readFileSync(DOWNLOADS_META_PATH, 'utf8'));
  } catch { return {}; }
}

function writeDownloadsMeta(data) {
  fs.mkdirSync(path.dirname(DOWNLOADS_META_PATH), { recursive: true });
  fs.writeFileSync(DOWNLOADS_META_PATH, JSON.stringify(data, null, 2), 'utf8');
}

ipcMain.handle('save-file-meta', (_, filePath, meta) => {
  const all = readDownloadsMeta();
  all[filePath] = meta;
  writeDownloadsMeta(all);
  return { success: true };
});

ipcMain.handle('get-file-meta', (_, filePath) => {
  const all = readDownloadsMeta();
  return all[filePath] || null;
});

// Open a locally downloaded file / launch it
// Layer 6: verify hash from catalog before opening
ipcMain.handle('open-file', async (_, filePath, expectedHash) => {
  const destPath = path.join(DOWNLOAD_DIR, filePath);
  if (!fs.existsSync(destPath)) return 'not-found';
  if (expectedHash) {
    const { ok } = security.verifyDownloadedFile(destPath, expectedHash);
    if (!ok) return 'integrity-failed';
  }
  return shell.openPath(destPath);
});

// Open the folder containing a downloaded file in the system file explorer
ipcMain.handle('open-file-folder', async (_, filePath) => {
  const destPath = path.join(DOWNLOAD_DIR, filePath);
  if (!fs.existsSync(destPath)) {
    // If file doesn't exist, open the parent download directory instead
    return shell.openPath(DOWNLOAD_DIR);
  }
  shell.showItemInFolder(destPath);
  return 'ok';
});

// Open downloads folder in system file explorer
ipcMain.handle('open-downloads', async () => {
  fs.mkdirSync(DOWNLOAD_DIR, { recursive: true });
  return shell.openPath(DOWNLOAD_DIR);
});

// Open external URL — allow whitelisted hosts only
const ALLOWED_EXTERNAL_HOSTS = new Set([
  'huggingface.co',
  'github.com',
  'raw.githubusercontent.com',
  'www.tiktok.com',
  'chahuadev.com',
  'www.chahuadev.com',
  'www.npmjs.com',
  'r2.chahuadev.com',
  'www.buymeacoffee.com',
  'buymeacoffee.com',
]);
ipcMain.handle('open-external-url', (_, url) => {
  if (typeof url !== 'string') return;
  try {
    const parsed = new URL(url);
    if (parsed.protocol !== 'https:') return;
    if (!ALLOWED_EXTERNAL_HOSTS.has(parsed.hostname)) return;
    shell.openExternal(parsed.toString());
  } catch (_) {
    return;
  }
});

// Download a file with streaming progress events
ipcMain.handle('download-file', (event, filePath, fileSize) => {
  return new Promise((resolve, reject) => {
    // Build download URL — encode each path segment individually
    const encodedPath = filePath.split('/').map(encodeURIComponent).join('/');
    const downloadUrl = `${R2_CDN_BASE}/${encodedPath}`;
    const destPath    = path.join(DOWNLOAD_DIR, filePath);

    // Ensure destination directory exists
    fs.mkdirSync(path.dirname(destPath), { recursive: true });

    function download(urlStr, redirectCount) {
      if (redirectCount > 15) return reject(new Error('Too many redirects'));
      let parsed;
      try { parsed = new URL(urlStr); } catch (e) { return reject(e); }
      const mod = parsed.protocol === 'https:' ? https : http;

      const req = mod.get(urlStr, {
        headers: { 'User-Agent': 'ChahuadevHub/1.0.0 (Electron)' }
      }, (res) => {
        // Follow redirect
        if (res.statusCode >= 300 && res.statusCode < 400 && res.headers.location) {
          res.resume();
          const nextUrl = new URL(res.headers.location, urlStr).toString();
          download(nextUrl, redirectCount + 1);
          return;
        }
        if (res.statusCode !== 200) {
          res.resume();
          return reject(new Error(`HTTP ${res.statusCode}`));
        }

        const total = parseInt(res.headers['content-length'] || fileSize || '0', 10);
        let downloaded = 0;
        const fileStream = fs.createWriteStream(destPath);

        res.on('data', (chunk) => {
          downloaded += chunk.length;
          fileStream.write(chunk);
          const pct = total > 0 ? downloaded / total : 0;
          if (!event.sender.isDestroyed()) {
            event.sender.send('download-progress', filePath, downloaded, total, pct);
          }
        });

        res.on('end', () => {
          fileStream.end(() => {
            resolve({ success: true, dest: destPath, downloaded });
          });
        });

        res.on('error', (err) => {
          fileStream.destroy();
          fs.unlink(destPath, () => {});
          reject(err);
        });
      });

      req.on('error', (err) => {
        fs.unlink(destPath, () => {});
        reject(err);
      });
      req.setTimeout(60000, () => {
        req.destroy(new Error('Download timeout'));
      });
    }

    download(downloadUrl, 0);
  });
});

// ════════════════════════════════════════════════════════════════════════════
// App Self-Update (Approach 1 + 2)
// ════════════════════════════════════════════════════════════════════════════

// Return current app version
ipcMain.handle('get-app-version', () => app.getVersion());

ipcMain.handle('updater:get-channel', () => UPDATE_CHANNEL);

ipcMain.handle('updater:get-status', () => ({
  initialized: updaterInitialized,
  channel: UPDATE_CHANNEL,
  ...updaterState
}));

ipcMain.handle('updater:check-now', async () => {
  if (!app.isPackaged || isDev) {
    return { ok: false, channel: UPDATE_CHANNEL, error: 'Updater is disabled in development mode.' };
  }
  if (!updaterInitialized) {
    return { ok: false, channel: UPDATE_CHANNEL, error: 'Updater is not initialized yet.' };
  }
  return checkForUpdatesNow();
});

// Fetch catalog.json from R2, compare with running version
ipcMain.handle('check-app-update', async () => {
  try {
    const catalog = await fetchJSON(R2_CATALOG_URL);
    const latestEntry = findCatalogEntry(catalog);
    if (!latestEntry || !latestEntry.version) {
      return { hasUpdate: false, error: `No catalog entry for ${APP_CATALOG_ID}` };
    }
    const current = app.getVersion();
    const latestVersion = String(latestEntry.version || '');
    const hasUpdate = semverGt(latestVersion, current);
    return {
      hasUpdate,
      current,
      latest:      latestVersion,
      releaseDate: String(latestEntry.releaseDate || ''),
      notes:       String(latestEntry.notes || ''),
      path:        String(latestEntry.path || ''),
      os:          String(latestEntry.os || '')
    };
  } catch (e) {
    return { hasUpdate: false, error: e.message };
  }
});

// ── npm self-update ───────────────────────────────────────────────────────────
// Runs: npm install -g @chahuadev/chahuadev-hub-app --foreground-scripts --force
// Uses exec() so Node's built-in shell handles npm resolution on all platforms.
// Security: command string is hardcoded — renderer passes no arguments.
ipcMain.handle('npm-self-update', (event) => {
  return new Promise((resolve) => {
    const CMD = 'npm install -g @chahuadev/chahuadev-hub-app --foreground-scripts --force';

    const send = (line) => {
      const trimmed = (line || '').toString().trim();
      if (trimmed && !event.sender.isDestroyed())
        event.sender.send('npm-update-log', trimmed);
    };

    const child = exec(CMD, { windowsHide: true });

    child.stdout.on('data', d => send(d));
    child.stderr.on('data', d => send(d));

    child.on('close', (code) => {
      resolve({ success: code === 0, code });
    });

    child.on('error', (err) => {
      send('ERROR: ' + err.message);
      resolve({ success: false, error: err.message });
    });
  });
});

// Relaunch app (kept for future use)
ipcMain.handle('relaunch-app', () => {
  app.relaunch();
  app.quit();
});

// Get npm global install path for a given package
ipcMain.handle('npm-get-install-path', (_, pkgName) => {
  return new Promise((resolve) => {
    exec('npm root -g', { windowsHide: true }, (err, stdout) => {
      if (err) return resolve(null);
      const root = stdout.trim();
      // Resolve scoped (@org/pkg) or unscoped (pkg) package path
      let pkgPath;
      if (pkgName && pkgName.startsWith('@')) {
        const parts = pkgName.slice(1).split('/');
        pkgPath = path.join(root, '@' + parts[0], parts[1] || '');
      } else if (pkgName) {
        pkgPath = path.join(root, pkgName);
      } else {
        pkgPath = path.join(root, '@chahuadev', 'chahuadev-hub-app');
      }
      resolve(fs.existsSync(pkgPath) ? pkgPath : root);
    });
  });
});

// Open the install folder for a given npm package (opens bin subdir if exists)
ipcMain.handle('open-npm-folder', (_, pkgName) => {
  return new Promise((resolve) => {
    exec('npm root -g', { windowsHide: true }, (err, stdout) => {
      if (err) return resolve('error');
      const root = stdout.trim();
      let pkgPath;
      if (pkgName && pkgName.startsWith('@')) {
        const parts = pkgName.slice(1).split('/');
        pkgPath = path.join(root, '@' + parts[0], parts[1] || '');
      } else if (pkgName) {
        pkgPath = path.join(root, pkgName);
      } else {
        return resolve('not-found');
      }
      if (!fs.existsSync(pkgPath)) return resolve('not-found');
      const binPath = path.join(pkgPath, 'bin');
      const openTarget = fs.existsSync(binPath) ? binPath : pkgPath;
      shell.openPath(openTarget);
      resolve('ok');
    });
  });
});

// Install any whitelisted npm package globally
ipcMain.handle('npm-install-package', (event, pkgName) => {
  if (!NPM_PKG_WHITELIST.has(pkgName)) {
    return Promise.resolve({ success: false, error: 'Package not in whitelist' });
  }
  return new Promise((resolve) => {
    const CMD = `npm install -g ${pkgName} --foreground-scripts --force`;
    const send = (line) => {
      const trimmed = (line || '').toString().trim();
      if (trimmed && !event.sender.isDestroyed())
        event.sender.send('npm-install-log', trimmed);
    };
    const child = exec(CMD, { windowsHide: true });
    child.stdout.on('data', d => send(d));
    child.stderr.on('data', d => send(d));
    child.on('close', (code) => resolve({ success: code === 0, code }));
    child.on('error', (err) => {
      send('ERROR: ' + err.message);
      resolve({ success: false, error: err.message });
    });
  });
});