/**
 * Video format detection and support level classification
 * Determines the optimal playback method for different video formats
 */

export interface VideoFormat {
  type: 'direct' | 'hls' | 'local-player'; // Removed 'fallback', added 'local-player'
  url: string;
  mimeType?: string;
  qualities?: QualityLevel[];
  supportLevel: 'native' | 'hls' | 'local-player-required'; // Updated 'limited' to 'local-player-required'
  warning?: string;
  action?: 'launch-local-player'; // New field for local player guidance
  recommendedPlayers?: string[]; // New field for player recommendations
  streamInfo?: {
    contentType: string;
    acceptRanges: string;
    supportsSeek: boolean;
    authentication: string;
  }; // New field for stream metadata
}

export interface QualityLevel {
  html: string;
  url: string;
  default?: boolean;
}

export interface VideoFile {
  id: number;
  title: string;
  path: string;
  size: number;
  thumbnail: string;
  type: string;
  codec_info?: string;
  bookmark_count?: number;
  avg_rating?: number;
  star_count?: number;
}

// Native browser support formats (direct streaming)
const NATIVE_SUPPORTED_FORMATS = [
  'mp4',  // H.264, H.265
  'webm', // VP8, VP9
  'ogg',  // Theora
  'ogv'
];

// Formats that work well with HLS streaming (but .ts files should be served directly)
const HLS_COMPATIBLE_FORMATS = [
  'mp4',
  'm4v', 
  // Note: .ts files are removed from here - they should be served directly
  'm2ts',
  'mts'
];

// MPEG Transport Stream formats - can be served via HLS or converted
const TS_STREAM_FORMATS = [
  'ts',   // MPEG Transport Stream - optimal for HLS streaming
  'm2ts', // Blu-ray Transport Stream
  'mts'   // AVCHD Transport Stream
];

// Formats with limited support (may need transcoding)
const LIMITED_SUPPORT_FORMATS = [
  'avi',
  'wmv', 
  'flv',
  'mkv',
  'mov',  // Some MOV files may work
  '3gp',
  'vob'
];

/**
 * Detect video format and determine optimal playback method
 * TRANSCODING REMOVED: Binary decision - native browser OR local player
 */
export function detectVideoFormat(video: VideoFile): VideoFormat {
  console.log('[FormatDetector] Input video:', video);
  const extension = getFileExtension(video.path).toLowerCase();
  console.log('[FormatDetector] Extracted extension:', extension);
  const codecInfo = parseCodecInfo(video.codec_info);
  console.log('[FormatDetector] Codec info:', codecInfo);
  
  // EXPLICIT TEST: Force .avi files to local player
  if (extension === 'avi') {
    console.log('[FormatDetector] .avi file detected, forcing local player');
    return createLocalPlayerFormat(video, extension);
  }
  
  // TRANSCODING DISABLED: No more transcoding fallback
  // If codec specifically needs transcoding, go directly to local player
  if (codecInfo.needsTranscoding) {
    console.log('[FormatDetector] Codec needs transcoding, using local player');
    return createLocalPlayerFormat(video, extension);
  }
  
  // Tier 1: Native browser support (direct streaming)
  if (NATIVE_SUPPORTED_FORMATS.includes(extension)) {
    console.log('[FormatDetector] Native format detected:', extension);
    return createDirectFormat(video, extension);
  }
  
  // Tier 1.5: MPEG Transport Stream files (optimal for HLS)
  if (TS_STREAM_FORMATS.includes(extension)) {
    console.log('[FormatDetector] TS format detected, using HLS streaming:', extension);
    return createTSHLSFormat(video, extension);
  }
  
  // Tier 2: HLS compatible formats - try direct first, HLS as backup
  if (HLS_COMPATIBLE_FORMATS.includes(extension)) {
    console.log('[FormatDetector] HLS compatible format detected:', extension);
    // For now, try direct streaming first, HLS as fallback
    // In future, we could detect if HLS is actually needed
    return createDirectFormat(video, extension);
  }
  
  // TRANSCODING DISABLED: All other formats go directly to local player
  // No more fallback to transcoding system
  console.log('[FormatDetector] Using local player for format:', extension);
  
  // Check if this is a format from LIMITED_SUPPORT_FORMATS
  if (LIMITED_SUPPORT_FORMATS.includes(extension)) {
    console.log('[FormatDetector] Format in LIMITED_SUPPORT_FORMATS, forcing local player');
  }
  
  return createLocalPlayerFormat(video, extension);
}

/**
 * Get file extension from path
 */
function getFileExtension(path: string): string {
  const basename = path.split('/').pop() || '';
  const parts = basename.split('.');
  return parts.length > 1 ? parts[parts.length - 1] : '';
}

/**
 * Parse codec information from video metadata
 */
function parseCodecInfo(codecInfo?: string): { needsTranscoding: boolean } {
  if (!codecInfo) return { needsTranscoding: false };
  
  try {
    const info = JSON.parse(codecInfo);
    return {
      needsTranscoding: info.needsTranscoding || false
    };
  } catch {
    return { needsTranscoding: false };
  }
}

/**
 * Create direct streaming format configuration
 */
function createDirectFormat(video: VideoFile, extension: string): VideoFormat {
  const mimeType = getMimeType(extension);
  
  return {
    type: 'direct',
    supportLevel: 'native',
    url: `/api/stream/direct/${video.id}`,
    mimeType,
    qualities: [
      {
        html: 'Auto',
        url: `/api/stream/direct/${video.id}`,
        default: true
      }
    ]
  };
}

/**
 * Create HLS streaming format configuration
 */
function createHLSFormat(video: VideoFile, extension: string): VideoFormat {
  return {
    type: 'hls',
    supportLevel: 'hls',
    url: `/api/stream/hls/${video.id}/playlist.m3u8`,
    qualities: [
      {
        html: 'Auto',
        url: `/api/stream/hls/${video.id}/playlist.m3u8`,
        default: true
      },
      {
        html: '1080p',
        url: `/api/stream/hls/${video.id}/playlist.m3u8?quality=1080`
      },
      {
        html: '720p',
        url: `/api/stream/hls/${video.id}/playlist.m3u8?quality=720`
      },
      {
        html: '480p',
        url: `/api/stream/hls/${video.id}/playlist.m3u8?quality=480`
      }
    ]
  };
}

/**
 * Create HLS format configuration for MPEG Transport Stream files
 * .ts files are already in HLS-compatible format, so we use HLS streaming
 */
function createTSHLSFormat(video: VideoFile, extension: string): VideoFormat {
  return {
    type: 'hls',
    supportLevel: 'hls',
    url: `/api/stream/hls/${video.id}/playlist.m3u8`,
    qualities: [
      {
        html: 'Auto (HLS)',
        url: `/api/stream/hls/${video.id}/playlist.m3u8`,
        default: true
      },
      {
        html: 'Direct Stream',
        url: `/api/stream/direct/${video.id}`
      }
    ]
  };
}

/**
 * Create direct TS format configuration for MPEG Transport Stream files
 * Alternative approach - serve .ts directly (may not work in all browsers)
 */
function createTSDirectFormat(video: VideoFile, extension: string): VideoFormat {
  const mimeType = getMimeType(extension);
  
  return {
    type: 'direct',
    supportLevel: 'native',
    url: `/api/stream/direct/${video.id}`,
    mimeType,
    qualities: [
      {
        html: 'Original (TS)',
        url: `/api/stream/direct/${video.id}`,
        default: true
      }
    ]
  };
}

/**
 * Create local player format configuration (replaces transcoding fallback)
 */
function createLocalPlayerFormat(video: VideoFile, extension: string): VideoFormat {
  const contentType = getMimeType(extension);
  
  // Use the optimized external streaming endpoint
  const baseUrl = `/api/external-stream/${video.id}`;
  
  return {
    type: 'local-player',
    supportLevel: 'local-player-required',
    url: baseUrl, // Optimized endpoint for external players
    action: 'launch-local-player',
    warning: 'This format requires a local video player',
    recommendedPlayers: getRecommendedPlayersForFormat(extension),
    streamInfo: {
      contentType,
      acceptRanges: 'bytes',
      supportsSeek: true,
      authentication: 'none'
    },
    qualities: [
      {
        html: 'Original',
        url: baseUrl,
        default: true
      }
    ]
  };
}

/**
 * Get recommended players based on format and platform
 */
function getRecommendedPlayersForFormat(extension: string): string[] {
  const players: string[] = ['vlc']; // VLC is always recommended as it's cross-platform
  
  // Platform-specific recommendations
  if (typeof window !== 'undefined') {
    const userAgent = window.navigator.userAgent.toLowerCase();
    const isMac = userAgent.includes('mac');
    const isWindows = userAgent.includes('win');
    const isLinux = userAgent.includes('linux');
    
    if (isMac) {
      players.push('iina', 'elmedia');
    } else if (isWindows) {
      players.push('potplayer');
    }
  } else {
    // Server-side: recommend all major players
    players.push('iina', 'elmedia', 'potplayer');
  }
  
  return players;
}

/**
 * Get MIME type for file extension
 */
function getMimeType(extension: string): string {
  const mimeTypes: Record<string, string> = {
    'mp4': 'video/mp4',
    'webm': 'video/webm',
    'ogg': 'video/ogg',
    'ogv': 'video/ogg',
    'm4v': 'video/x-m4v',
    'ts': 'video/mp2t',
    'm2ts': 'video/mp2t',
    'mts': 'video/mp2t'
  };
  
  return mimeTypes[extension] || 'video/mp4'; // Default fallback
}

/**
 * Check if format is supported by ArtPlayer natively
 */
export function isNativeSupported(format: VideoFormat): boolean {
  return format.supportLevel === 'native';
}

/**
 * Check if format requires HLS streaming
 */
export function requiresHLS(format: VideoFormat): boolean {
  return format.type === 'hls';
}

/**
 * Check if format requires local player (replaces transcoding fallback)
 */
export function requiresLocalPlayer(format: VideoFormat): boolean {
  return format.type === 'local-player';
}

/**
 * Check if format requires fallback to transcoding (DEPRECATED - transcoding removed)
 */
export function requiresFallback(format: VideoFormat): boolean {
  // TRANSCODING DISABLED: This function is deprecated
  // All formats now either work natively or require local player
  return false;
}

/**
 * ArtPlayer is now the only player used throughout the application
 * This function is kept for backward compatibility but always returns 'artplayer'
 */
export function getOptimalPlayerType(format: VideoFormat): 'artplayer' {
  // Always return ArtPlayer since it's the only player we use now
  return 'artplayer';
}