import { exec } from 'child_process';
import { promisify } from 'util';
import * as fs from 'fs';
import * as path from 'path';

const execAsync = promisify(exec);

export interface ThumbnailOptions {
  videoId: string;
  timeStamp?: string; // Format: "00:01:30" or "90" (seconds)
  width?: number;
  height?: number;
  quality?: number;
}

export class ThumbnailGenerator {
  private thumbnailDir: string;

  constructor() {
    this.thumbnailDir = path.join(process.cwd(), 'thumbnails');
    this.ensureThumbnailDir();
  }

  private ensureThumbnailDir() {
    if (!fs.existsSync(this.thumbnailDir)) {
      fs.mkdirSync(this.thumbnailDir, { recursive: true });
    }
  }

  async generateThumbnail(options: ThumbnailOptions): Promise<string | null> {
    const { videoId, timeStamp = "5", width = 400, height = 225, quality = 85 } = options;
    
    // Create unique filename based on parameters
    const filename = `${videoId}_${timeStamp.replace(/:/g, '-')}_${width}x${height}.jpg`;
    const outputPath = path.join(this.thumbnailDir, filename);
    
    // Check if thumbnail already exists
    if (fs.existsSync(outputPath)) {
      return outputPath;
    }

    try {
      // Use Bunny.net direct video URL for FFmpeg
      const videoUrl = `https://vz-7982dfc4-cc8.b-cdn.net/${videoId}/playlist.m3u8`;
      
      // FFmpeg command to extract frame at specific time
      const ffmpegCommand = [
        'ffmpeg',
        '-i', `"${videoUrl}"`,
        '-ss', timeStamp,
        '-vframes', '1',
        '-vf', `scale=${width}:${height}`,
        '-q:v', quality.toString(),
        `"${outputPath}"`,
        '-y'
      ].join(' ');

      console.log(`Generating thumbnail: ${ffmpegCommand}`);
      
      const { stdout, stderr } = await execAsync(ffmpegCommand);
      
      if (fs.existsSync(outputPath)) {
        console.log(`Thumbnail generated successfully: ${outputPath}`);
        return outputPath;
      } else {
        console.error('Thumbnail file was not created');
        return null;
      }
      
    } catch (error) {
      console.error('Error generating thumbnail:', error);
      return null;
    }
  }

  async generateMultipleThumbnails(videoId: string, timestamps: string[]): Promise<string[]> {
    const results: string[] = [];
    
    for (const timestamp of timestamps) {
      const thumbnailPath = await this.generateThumbnail({
        videoId,
        timeStamp: timestamp
      });
      
      if (thumbnailPath) {
        results.push(thumbnailPath);
      }
    }
    
    return results;
  }

  async enhanceThumbnail(inputPath: string, outputPath: string): Promise<string | null> {
    try {
      // Use ImageMagick to enhance the thumbnail
      const magickCommand = [
        'convert',
        `"${inputPath}"`,
        '-auto-level',
        '-enhance',
        '-unsharp', '0x1',
        `"${outputPath}"`
      ].join(' ');

      await execAsync(magickCommand);
      
      if (fs.existsSync(outputPath)) {
        return outputPath;
      }
      
      return null;
    } catch (error) {
      console.error('Error enhancing thumbnail:', error);
      return null;
    }
  }

  listThumbnails(videoId: string): string[] {
    try {
      const files = fs.readdirSync(this.thumbnailDir);
      return files
        .filter(file => file.startsWith(videoId) && file.endsWith('.jpg'))
        .map(file => path.join(this.thumbnailDir, file));
    } catch (error) {
      console.error('Error listing thumbnails:', error);
      return [];
    }
  }

  deleteThumbnail(videoId: string, timestamp?: string): boolean {
    try {
      if (timestamp) {
        // Delete specific thumbnail
        const filename = `${videoId}_${timestamp.replace(/:/g, '-')}_400x225.jpg`;
        const filePath = path.join(this.thumbnailDir, filename);
        if (fs.existsSync(filePath)) {
          fs.unlinkSync(filePath);
          return true;
        }
      } else {
        // Delete all thumbnails for video
        const files = fs.readdirSync(this.thumbnailDir);
        const videoThumbnails = files.filter(file => file.startsWith(videoId));
        
        for (const file of videoThumbnails) {
          fs.unlinkSync(path.join(this.thumbnailDir, file));
        }
        
        return videoThumbnails.length > 0;
      }
      
      return false;
    } catch (error) {
      console.error('Error deleting thumbnail:', error);
      return false;
    }
  }
}