xtremflow/bin/server.dart

import 'dart:io';
import 'dart:async';
import 'dart:convert';
import 'package:shelf/shelf.dart';
import 'package:shelf/shelf_io.dart' as shelf_io;
import 'package:shelf_static/shelf_static.dart';
import 'package:shelf_router/shelf_router.dart';
import 'package:http/http.dart' as http;
import 'package:args/args.dart';
import 'database/database.dart';
import 'models/user.dart';
import 'api/auth_handler.dart';
import 'api/users_handler.dart';
import 'api/auth_handler.dart';
import 'api/users_handler.dart';
import 'api/playlists_handler.dart';
import 'api/settings_handler.dart';
import 'middleware/auth_middleware.dart';
import 'middleware/security_middleware.dart';
import 'services/cleanup_service.dart';

void main(List<String> args) async {
  // Parse command line arguments
  final parser = ArgParser()
    ..addOption('port', abbr: 'p', defaultsTo: '8089')
    ..addOption('path', defaultsTo: '/app/web');
  
  final result = parser.parse(args);
  final port = int.parse(result['port']);
  final webPath = result['path'];

  // Initialize database
  final db = AppDatabase();
  await db.init();
  await db.seedAdmin();

  // Create API handlers
  final authHandler = AuthHandler(db);
  final playlistsHandler = PlaylistsHandler(db);
  final usersHandler = UsersHandler(db);
  final settingsHandler = SettingsHandler(db);

  // Setup router
  final apiRouter = Router()
    // Auth endpoints (no auth middleware) - full path including /api/
    ..mount('/api/auth', authHandler.router)
    // Playlists endpoints (with auth middleware)
    ..mount('/api/playlists', Pipeline()
      .addMiddleware(authMiddleware(db))
      .addHandler(playlistsHandler.router.call))
    // Users endpoints (with auth middleware)
    ..mount('/api/users', Pipeline()
      .addMiddleware(authMiddleware(db))
      .addHandler(usersHandler.router.call))
    // Settings endpoints (with auth middleware)
    ..mount('/api/settings', Pipeline()
      .addMiddleware(authMiddleware(db))
      .addHandler(settingsHandler.router.call));

  // Initialize Cleanup Service
  final cleanupService = CleanupService();
  // Target system temp directory (often used by FFmpeg/Dart)
  cleanupService.addTarget(Directory.systemTemp);
  // Target local logs/cache if they exist
  cleanupService.addTarget(Directory('/app/data/logs'));
  cleanupService.addTarget(Directory('/app/data/tmp'));
  
  cleanupService.start();

  // Admin Routes (protected)
  apiRouter.mount('/api/admin', Pipeline()
      .addMiddleware(authMiddleware(db))
      .addHandler((Request request) {
        final router = Router();
        
        // POST /api/admin/purge
        router.post('/purge', (Request req) async {
          final user = req.context['user'] as User?;
          if (user == null || !user.isAdmin) {
             return Response.forbidden(jsonEncode({'error': 'Admin access required'}));
          }
          
          final result = await cleanupService.runCleanup();
          return Response.ok(
            jsonEncode(result),
            headers: {'content-type': 'application/json'},
          );
        });
        
        return router(request);
      }),);

  // Create handlers
  // Create static handler
  final baseStaticHandler = createStaticHandler(
    webPath,
    defaultDocument: 'index.html',
    listDirectories: false,
  );

  // Wrap static handler to enforce cache policies
  Handler staticHandler = (Request request) async {
    final response = await baseStaticHandler(request);
    
    // Disable cache for entry points to ensure updates are seen immediately
    final path = request.url.path;
    if (path.isEmpty || 
        path == 'index.html' || 
        path == 'flutter_service_worker.js' || 
        path.endsWith('.json')) { // version.json etc
      return response.change(headers: {
        'Cache-Control': 'no-store, no-cache, must-revalidate, max-age=0',
        'Pragma': 'no-cache',
        'Expires': '0',
      });
    }
    
    // Allow aggressive caching for hashed assets (images, compiled JS)
    // Flutter web builds usually hash main.dart.js, but let's be safe with 1 day
    return response.change(headers: {
      'Cache-Control': 'public, max-age=86400', 
    });
  };

  // Main handler with API proxy and FFmpeg streaming
  final handler = Cascade()
    .add(_createApiHandler(apiRouter))
    .add(_createStreamHandler())  // FFmpeg streaming endpoint
    .add(_createXtreamProxyHandler())
    // .add(_createHlsHandler())  // REMOVED: HLS obsolete with direct stream
    .add(staticHandler)
    .handler;



  // Add middleware
  final pipeline = Pipeline()
    .addMiddleware(logRequests())
    .addMiddleware(securityHeadersMiddleware()) // Basic Headers
    .addMiddleware(honeypotMiddleware())        // Trap Bots
    .addMiddleware(rateLimitMiddleware())       // Anti-DoS
    .addMiddleware(_corsMiddleware())
    .addHandler(handler);

  // Start server
  final server = await shelf_io.serve(
    pipeline,
    InternetAddress.anyIPv4,
    port,
  );

  print('Server started on port ${server.port}');
  print('Serving static files from: $webPath');
  print('REST API available at: /api/auth/* and /api/playlists/*');
  print('Xtream proxy available at: /api/xtream/*');
  print('FFmpeg streaming available at: /api/stream/*');
  
  // Clean expired sessions periodically (every hour)
  Timer.periodic(const Duration(hours: 1), (_) {
    db.cleanExpiredSessions();
    print('Cleaned expired sessions');
  });
}

/// Create API handler
Handler _createApiHandler(Router apiRouter) {
  return (Request request) async {
    final path = request.url.path;
    
    // Only handle /api/* requests (excluding /api/xtream)
    if (path.startsWith('api/') && !path.startsWith('api/xtream/')) {
      return apiRouter(request);
    }
    
    return Response.notFound('Not found');
  };
}

/// CORS middleware to allow cross-origin requests
Middleware _corsMiddleware() {
  return (Handler handler) {
    return (Request request) async {
      // Handle preflight requests
      if (request.method == 'OPTIONS') {
        return Response.ok('', headers: _corsHeaders);
      }

      // Process request and add CORS headers to response
      final response = await handler(request);
      return response.change(headers: _corsHeaders);
    };
  };
}

final _corsHeaders = {
  'Access-Control-Allow-Origin': '*',
  'Access-Control-Allow-Methods': 'GET, POST, PUT, DELETE, OPTIONS',
  'Access-Control-Allow-Headers': 'Origin, Content-Type, Accept, Authorization',
};

/// Create Xtream proxy handler with M3U8 URL rewriting support
Handler _createXtreamProxyHandler() {
  return (Request request) async {
    final path = request.url.path;

    // Only handle /api/xtream/* requests
    if (!path.startsWith('api/xtream/')) {
      return Response.notFound('Not found');
    }

    try {
      // Extract target URL from request
      // Format: /api/xtream/http://server:port/path
      // Note: URL might be URL-encoded (e.g., http%3A%2F%2F...)
      String apiPath = path.substring('api/xtream/'.length);
      
      // Decode URL if it's encoded (http%3A%2F%2F -> http://)
      if (apiPath.startsWith('http%3A') || apiPath.startsWith('https%3A')) {
        apiPath = Uri.decodeComponent(apiPath);
      }
      
      // The client will send the full URL after /api/xtream/
      if (!apiPath.startsWith('http://') && !apiPath.startsWith('https://')) {
        return Response.badRequest(
          body: 'Invalid API URL. Expected format: /api/xtream/http://...',
        );
      }

      // Reconstruct the full target URL with query parameters
      String fullUrl = apiPath;
      if (request.url.query.isNotEmpty) {
        // If the target URL already has query params, append with &
        if (fullUrl.contains('?')) {
          fullUrl = '$fullUrl&${request.url.query}';
        } else {
          fullUrl = '$fullUrl?${request.url.query}';
        }
      }
      
      final targetUrl = Uri.parse(fullUrl);
      final baseUrl = '${targetUrl.scheme}://${targetUrl.host}${targetUrl.hasPort ? ':${targetUrl.port}' : ''}';
      
      // Check if this is a video file that needs streaming
      final lowerPath = targetUrl.path.toLowerCase();
      final isVideoFile = lowerPath.endsWith('.mp4') || 
                          lowerPath.endsWith('.mkv') || 
                          lowerPath.endsWith('.avi') ||
                          lowerPath.endsWith('.ts') ||
                          lowerPath.endsWith('.m4v') ||
                          lowerPath.contains('/movie/') ||
                          lowerPath.contains('/series/');

      print('Proxying request to: $targetUrl (video streaming: $isVideoFile)');

      // For video files, use streaming with Range support for seeking
      if (isVideoFile) {
        final rangeHeader = request.headers['range'];
        return _streamVideoFile(targetUrl, rangeHeader);
      }

      // Headers to simulate a legitimate IPTV client (VLC/Kodi style)
      final proxyHeaders = {
        'User-Agent': 'VLC/3.0.18 LibVLC/3.0.18',
        'Accept': '*/*',
        'Accept-Encoding': 'identity',
        'Connection': 'keep-alive',
        'Icy-MetaData': '1',
      };

      // Use simple http.get/post for non-video content
      http.Response response;
      if (request.method == 'GET') {
        response = await http.get(targetUrl, headers: proxyHeaders).timeout(
          const Duration(seconds: 30),
          onTimeout: () => http.Response('Request timeout', 504),
        );
      } else if (request.method == 'POST') {
        final body = await request.readAsString();
        response = await http.post(targetUrl, headers: proxyHeaders, body: body).timeout(
          const Duration(seconds: 30),
          onTimeout: () => http.Response('Request timeout', 504),
        );
      } else {
        return Response(405, body: 'Method not allowed');
      }

      // Check if this is an M3U8/HLS playlist that needs URL rewriting
      final contentType = response.headers['content-type'] ?? '';
      final isM3u8 = fullUrl.endsWith('.m3u8') || 
                     contentType.contains('application/vnd.apple.mpegurl') ||
                     contentType.contains('application/x-mpegurl') ||
                     contentType.contains('audio/mpegurl');

      if (isM3u8 && response.statusCode == 200) {
        // Rewrite URLs in M3U8 playlist to go through proxy
        final rewrittenBody = _rewriteM3u8Urls(
          response.body, 
          baseUrl, 
          targetUrl.path,
          request.requestedUri.origin,
        );
        
        print('Rewrote M3U8 playlist URLs for: $targetUrl');
        
        return Response(
          response.statusCode,
          body: rewrittenBody,
          headers: {
            'content-type': 'application/vnd.apple.mpegurl',
            'access-control-allow-origin': '*',
          },
        );
      }

      return Response(
        response.statusCode,
        body: response.bodyBytes,
        headers: {
          'content-type': response.headers['content-type'] ?? 'application/json',
          'access-control-allow-origin': '*',
          // Forward cache headers from upstream
          if (response.headers.containsKey('cache-control'))
            'cache-control': response.headers['cache-control']!,
          if (response.headers.containsKey('expires'))
            'expires': response.headers['expires']!,
          if (response.headers.containsKey('etag'))
            'etag': response.headers['etag']!,
          if (response.headers.containsKey('last-modified'))
            'last-modified': response.headers['last-modified']!,
        },
      );
    } catch (e, stackTrace) {
      print('Proxy error: $e');
      print(stackTrace);
      return Response.internalServerError(
        body: jsonEncode({'error': 'Proxy error', 'message': e.toString()}),
        headers: {'content-type': 'application/json'},
      );
    }
  };
}

/// Stream video file using HttpClient with Range support for seeking
Future<Response> _streamVideoFile(Uri targetUrl, String? rangeHeader) async {
  final maxRedirects = 5;
  var currentUrl = targetUrl;
  
  for (var i = 0; i < maxRedirects; i++) {
    try {
      final client = HttpClient();
      // Increase timeouts for large video files
      client.connectionTimeout = const Duration(seconds: 60);
      client.idleTimeout = const Duration(minutes: 5);
      
      final req = await client.getUrl(currentUrl);
      req.followRedirects = false; // We handle redirects manually to preserve Range header
      
      req.headers.set('User-Agent', 'VLC/3.0.18 LibVLC/3.0.18');
      req.headers.set('Accept', '*/*');
      req.headers.set('Connection', 'keep-alive');
      req.headers.set('Accept-Encoding', 'identity');
      
      // Forward the Range header for seeking support
      if (rangeHeader != null && rangeHeader.isNotEmpty) {
        if (!rangeHeader.startsWith('bytes=')) {
          rangeHeader = 'bytes=$rangeHeader';
        }
        req.headers.set(HttpHeaders.rangeHeader, rangeHeader);
        print('Video streaming with Range: $rangeHeader (Redirect $i)');
      }
      
      client.autoUncompress = false;
      
      final response = await req.close();
      
      // Handle Redirects (301, 302, 303, 307, 308)
      if (response.statusCode >= 300 && response.statusCode < 400) {
        final location = response.headers.value(HttpHeaders.locationHeader);
        if (location != null) {
          print('Redirecting stream to: $location');
          currentUrl = Uri.parse(location);
          await response.drain(); // Drain body to release connection
          continue; // Loop to next request
        }
      }
      
      // Get content type from response
      final contentType = response.headers.contentType?.mimeType ?? 'video/mp4';
      
      // Build response headers for optimal streaming/buffering
      final responseHeaders = <String, String>{
        'content-type': contentType,
        'access-control-allow-origin': '*',
        'accept-ranges': 'bytes',
        'cache-control': 'no-cache',
        'connection': 'keep-alive',
      };
      
      // Add Content-Length if available
      if (response.contentLength > 0) {
        responseHeaders['content-length'] = response.contentLength.toString();
      }
      
      // Add Content-Range if this is a partial response (206)
      final contentRange = response.headers.value(HttpHeaders.contentRangeHeader);
      if (contentRange != null) {
        responseHeaders[HttpHeaders.contentRangeHeader] = contentRange;
      }
      
      // Propagate Accept-Ranges
      responseHeaders[HttpHeaders.acceptRangesHeader] = 'bytes';
      
      // Return appropriate status code
      return Response(
        response.statusCode,
        body: response,
        headers: responseHeaders,
      );
      
    } catch (e) {
      print('Video streaming exception: $e');
      if (i == maxRedirects - 1) {
         return Response.internalServerError(
           body: jsonEncode({'error': 'Video streaming error', 'message': e.toString()}),
           headers: {'content-type': 'application/json'},
         );
      }
    }
  }
  
  return Response.internalServerError(body: 'Too many redirects');
}

/// Rewrite URLs in M3U8 playlist to go through the proxy
/// 
/// Handles both relative and absolute URLs in HLS playlists
String _rewriteM3u8Urls(String m3u8Content, String baseUrl, String originalPath, String proxyOrigin) {
  final lines = m3u8Content.split('\n');
  final rewrittenLines = <String>[];
  
  // Get directory path for relative URL resolution
  final pathSegments = originalPath.split('/');
  pathSegments.removeLast(); // Remove filename
  final basePath = pathSegments.join('/');
  
  for (final line in lines) {
    final trimmedLine = line.trim();
    
    // Skip empty lines and comments (except URI in comments)
    if (trimmedLine.isEmpty) {
      rewrittenLines.add(line);
      continue;
    }
    
    // Handle lines that contain URLs (not starting with #, or EXT-X-KEY/EXT-X-MAP with URI)
    if (!trimmedLine.startsWith('#')) {
      // This is a segment URL
      final rewrittenUrl = _rewriteUrl(trimmedLine, baseUrl, basePath, proxyOrigin);
      rewrittenLines.add(rewrittenUrl);
    } else if (trimmedLine.contains('URI="')) {
      // Handle EXT-X-KEY, EXT-X-MAP, etc. with URI attribute
      final rewrittenLine = trimmedLine.replaceAllMapped(
        RegExp(r'URI="([^"]+)"'),
        (match) {
          final uri = match.group(1)!;
          final rewrittenUri = _rewriteUrl(uri, baseUrl, basePath, proxyOrigin);
          return 'URI="$rewrittenUri"';
        },
      );
      rewrittenLines.add(rewrittenLine);
    } else {
      rewrittenLines.add(line);
    }
  }
  
  return rewrittenLines.join('\n');
}

/// Rewrite a single URL to go through the proxy
String _rewriteUrl(String url, String baseUrl, String basePath, String proxyOrigin) {
  String fullUrl;
  
  if (url.startsWith('http://') || url.startsWith('https://')) {
    // Already absolute URL
    fullUrl = url;
  } else if (url.startsWith('/')) {
    // Absolute path, relative to server root
    fullUrl = '$baseUrl$url';
  } else {
    // Relative path, relative to current directory
    fullUrl = '$baseUrl$basePath/$url';
  }
  
  // Wrap with proxy
  return '$proxyOrigin/api/xtream/$fullUrl';
}

// ============================================
// FFmpeg Stream Transcoding Handler
// ============================================

/// Active FFmpeg processes by stream ID
final Map<String, Process> _activeStreams = {};

/// Create handler for FFmpeg streaming
/// 
/// This endpoint starts an FFmpeg process that connects to the IPTV server
/// with proper headers and transcodes the stream to local HLS files.
Handler _createStreamHandler() {
  return (Request request) async {
    final path = request.url.path;

    // Only handle /api/stream/* requests
    if (!path.startsWith('api/stream/')) {
      return Response.notFound('Not found');
    }

    try {
      // Extract stream ID
      final pathParts = path.split('/');
      if (pathParts.length < 3) {
        return Response.badRequest(body: 'Invalid stream path');
      }
      
      final streamId = pathParts[2];
      
      // Get parameters
      final iptvUrl = request.url.queryParameters['url'];
      final quality = request.url.queryParameters['quality'] ?? 'high';
      final start = request.url.queryParameters['start']; // Start time in seconds
      
      if (iptvUrl == null || iptvUrl.isEmpty) {
        return Response.badRequest(body: 'Missing url parameter');
      }

      print('Starting Direct Stream for ID: $streamId');
      print('Source: $iptvUrl');

      // Setup FFmpeg arguments for fMP4 piping
      // Determine if it's VOD or Live
      final isVod = streamId.startsWith('vod_'); // Or use extension check
      
      final ffmpegArgs = <String>[
        '-hide_banner',
        '-loglevel', 'error', // Minimize logs, only errors
        '-user_agent', 'VLC/3.0.18 LibVLC/3.0.18',
        '-headers', 'Accept: */*\r\nConnection: keep-alive\r\n',
        
        // Input resilience flags
        '-reconnect', '1',
        '-reconnect_streamed', '1',
        '-reconnect_delay_max', '10',
        '-reconnect_on_network_error', '1',
        '-reconnect_on_http_error', '4xx,5xx',
        '-rw_timeout', '15000000', // 15s timeout
        
        // Probing settings to ensure stream detection
        '-analyzeduration', '20000000', // 20s
        '-probesize', '10000000',      // 10MB
        
        '-i', iptvUrl,
        
        // Output format: MPEG-TS for streaming (compatible with mpegts.js)
        '-f', 'mpegts',
      ];

      // Add seeking support if start time is provided
      if (start != null && start.isNotEmpty) {
        // Insert -ss before -i for faster seeking (input seeking)
        final inputIndex = ffmpegArgs.indexOf('-i');
        if (inputIndex != -1) {
          ffmpegArgs.insertAll(inputIndex, ['-ss', start]);
        }
      }

      // Video: Transcode based on quality
      // High = Copy (efficient), Low/Medium = Transcode to H.264 (compatible)
      if (quality == 'high') {
        ffmpegArgs.addAll(['-c:v', 'copy']);
      } else {
        // Transcode to H.264 (Baseline profile for max mobile compatibility)
        ffmpegArgs.addAll([
          '-c:v', 'libx264',
          '-preset', 'ultrafast', // Critical for live streaming
          '-tune', 'zerolatency',
          '-profile:v', 'baseline',
          '-level', '3.0',
          '-pix_fmt', 'yuv420p', // Ensure standard pixel format for web
          '-g', '60', // Keyframe interval (2s at 30fps) for seeking
        ]);

        if (quality == 'low') {
          // Low: ~480p, 800k
          ffmpegArgs.addAll([
            '-vf', 'scale=-2:480',
            '-b:v', '800k',
            '-maxrate', '800k',
            '-bufsize', '1600k',
          ]);
        } else {
          // Medium: Original res (or cap at 720p?), 2500k
          ffmpegArgs.addAll([
            '-b:v', '2500k',
            '-maxrate', '2500k',
            '-bufsize', '5000k',
          ]);
        }
      }
      
      // Audio: Transcode to AAC is SAFEST for browsers
      // (Many IPTV streams typically use MP2/AC3 which browsers hate)
      ffmpegArgs.addAll([
        '-c:a', 'aac',
        '-b:a', '128k',
        '-ar', '44100',
        '-ac', '2',
        
        // Fix for MPEG-TS timestamps
        '-fflags', '+genpts',
        
        // Output to stdout pipe
        'pipe:1',
      ]);

      // Start the process
      final process = await Process.start('ffmpeg', ffmpegArgs);
      
      // Manage process lifecycle
      // We use a StreamController to pipe stdout to the response
      // AND detect when the client disconnects to kill the process.
      final controller = StreamController<List<int>>();
      
      // Pipe stdout to controller
      process.stdout.listen(
        (data) {
          if (!controller.isClosed) controller.add(data);
        },
        onError: (e) {
          print('FFmpeg stdout error: $e');
          if (!controller.isClosed) controller.addError(e);
        },
        onDone: () {
          print('FFmpeg process finished for $streamId');
          if (!controller.isClosed) controller.close();
        },
      );

      // Log stderr for debug
      process.stderr.transform(utf8.decoder).listen((data) {
        if (data.contains('Error') || data.contains('error')) {
          print('FFmpeg Error [$streamId]: $data');
        }
      });

      // CLEANUP: When the HTTP client disconnects, the stream subscription
      // will be cancelled. We MUST kill the FFmpeg process then.
      controller.onCancel = () {
        print('Client disconnected for $streamId. Killing FFmpeg...');
        process.kill();
      };

      return Response.ok(
        controller.stream,
        headers: {
          'Content-Type': 'video/MP2T',
          'Access-Control-Allow-Origin': '*',
          'Cache-Control': 'no-cache, no-store',
          'Connection': 'keep-alive',
        },
      );

    } catch (e, stackTrace) {
      print('Stream setup error: $e');
      print(stackTrace);
      return Response.internalServerError(
        body: jsonEncode({'error': 'Stream setup error', 'message': e.toString()}),
        headers: {'content-type': 'application/json'},
      );
    }
  };
}