import { S3Client, PutObjectCommand, GetObjectCommand } from '@aws-sdk/client-s3';
import { getSignedUrl } from '@aws-sdk/s3-request-presigner';
import { v4 as uuidv4 } from 'uuid';
import sharp from 'sharp';
import { logger } from '../config/logger.js';

const s3Client = new S3Client({
  region: process.env.AWS_REGION || 'us-east-1',
  credentials: {
    accessKeyId: process.env.AWS_ACCESS_KEY_ID || '',
    secretAccessKey: process.env.AWS_SECRET_ACCESS_KEY || ''
  }
});

const BUCKET_NAME = process.env.AWS_S3_BUCKET || '';

export const s3Service = {
  getUploadUrl: async (fileName: string, fileType: string) => {
    const imageId = uuidv4();
    const key = `uploads/${imageId}-${fileName}`;

    const command = new PutObjectCommand({
      Bucket: BUCKET_NAME,
      Key: key,
      ContentType: fileType
    });

    try {
      const uploadUrl = await getSignedUrl(s3Client, command, { expiresIn: 3600 });
      logger.info(`Generated pre-signed URL for upload: ${key}`);
      return { uploadUrl, imageId, key };
    } catch (error) {
      logger.error('Error generating pre-signed URL:', error);
      throw error;
    }
  },

  optimizeAndUpload: async (buffer: Buffer, key: string, resolution: { width: number; height: number }) => {
    try {
      let sharpInstance = sharp(buffer);
      
      // Get image metadata
      const metadata = await sharpInstance.metadata();
      
      // Resize if resolution is specified
      if (resolution.width > 0 && resolution.height > 0) {
        sharpInstance = sharpInstance.resize(resolution.width, resolution.height, {
          fit: 'inside',
          withoutEnlargement: true
        });
      }

      // Convert to WebP for better compression
      const optimizedBuffer = await sharpInstance
        .webp({ quality: 80 })
        .toBuffer();

      // Upload optimized image
      const optimizedKey = key.replace(/\.[^/.]+$/, '.webp');
      await s3Client.send(new PutObjectCommand({
        Bucket: BUCKET_NAME,
        Key: optimizedKey,
        Body: optimizedBuffer,
        ContentType: 'image/webp'
      }));

      logger.info(`Successfully optimized and uploaded image: ${optimizedKey}`);
      
      return {
        key: optimizedKey,
        width: metadata.width,
        height: metadata.height,
        format: 'webp',
        size: optimizedBuffer.length
      };
    } catch (error) {
      logger.error('Error optimizing and uploading image:', error);
      throw error;
    }
  }
};