import express from 'express';
import path from 'path';
import fs from 'fs';

const router = express.Router();

// Desktop app download endpoint
router.get('/desktop', async (req, res) => {
  try {
    // Path to the installer
    const installerPath = path.join(
      process.cwd(),
      'shell',
      'aethex-shell',
      'src-tauri',
      'target',
      'release',
      'bundle',
      'nsis',
      'AeThex-OS_0.1.0_x64-setup.exe'
    );

    // Check if file exists
    if (!fs.existsSync(installerPath)) {
      console.log('[Download] Installer not found at', installerPath);
      return res.status(404).json({
        error: 'Installer not available',
        message: 'The desktop installer is not yet available. It will be uploaded soon.',
        note: 'For development: Run "npm run build:tauri" in shell/aethex-shell to build the installer'
      });
    }

    // Get file stats
    const stats = fs.statSync(installerPath);

    // Set headers
    res.setHeader('Content-Type', 'application/octet-stream');
    res.setHeader('Content-Disposition', 'attachment; filename="AeThex-OS-setup.exe"');
    res.setHeader('Content-Length', stats.size);

    // Stream the file
    const fileStream = fs.createReadStream(installerPath);
    fileStream.pipe(res);

    fileStream.on('error', (error) => {
      console.error('Error streaming installer:', error);
      if (!res.headersSent) {
        res.status(500).json({ error: 'Failed to download installer' });
      }
    });

    // Log download
    console.log(`[Download] Desktop installer downloaded by ${req.ip}`);

  } catch (error) {
    console.error('Error serving installer:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});

// Get latest version info (for auto-update checks)
router.get('/version', async (req, res) => {
  try {
    // Read version from package.json
    const packagePath = path.join(
      process.cwd(),
      'shell',
      'aethex-shell',
      'package.json'
    );

    const packageJson = JSON.parse(fs.readFileSync(packagePath, 'utf-8'));

    res.json({
      version: packageJson.version,
      releaseDate: new Date().toISOString(),
      downloadUrl: `${req.protocol}://${req.get('host')}/api/download/desktop`,
      releaseNotes: [
        'Initial MVP release',
        'Full IDE with Monaco editor',
        'Terminal integration',
        'AeThex Language compiler',
        'Compliance tools built-in'
      ],
      minimumVersion: '0.1.0'
    });
  } catch (error) {
    console.error('Error fetching version info:', error);
    res.status(500).json({ error: 'Failed to fetch version info' });
  }
});

// MSI installer download
router.get('/desktop/msi', async (req, res) => {
  try {
    const installerPath = path.join(
      process.cwd(),
      'shell',
      'aethex-shell',
      'src-tauri',
      'target',
      'release',
      'bundle',
      'msi',
      'AeThex-OS_0.1.0_x64_en-US.msi'
    );

    if (!fs.existsSync(installerPath)) {
      return res.status(404).json({ error: 'MSI installer not found' });
    }

    const stats = fs.statSync(installerPath);

    res.setHeader('Content-Type', 'application/octet-stream');
    res.setHeader('Content-Disposition', 'attachment; filename="AeThex-OS-setup.msi"');
    res.setHeader('Content-Length', stats.size);

    const fileStream = fs.createReadStream(installerPath);
    fileStream.pipe(res);

    console.log(`[Download] MSI installer downloaded by ${req.ip}`);

  } catch (error) {
    console.error('Error serving MSI installer:', error);
    res.status(500).json({ error: 'Internal server error' });
  }
});

export default router;