import { S3Client, PutObjectCommand, DeleteObjectCommand } from '@aws-sdk/client-s3';
import sharp from 'sharp';
import config from '../config/index.js';

// S3 클라이언트 생성
const s3Client = new S3Client({
  endpoint: config.s3.endpoint,
  region: 'us-east-1',
  credentials: {
    accessKeyId: config.s3.accessKey,
    secretAccessKey: config.s3.secretKey,
  },
  forcePathStyle: true,
});

const BUCKET = config.s3.bucket;
const PUBLIC_URL = config.s3.publicUrl;

/**
 * 이미지를 3가지 해상도로 변환
 */
async function processImage(buffer) {
  const [originalBuffer, mediumBuffer, thumbBuffer] = await Promise.all([
    sharp(buffer).webp({ lossless: true }).toBuffer(),
    sharp(buffer)
      .resize(800, null, { withoutEnlargement: true })
      .webp({ quality: 85 })
      .toBuffer(),
    sharp(buffer)
      .resize(400, null, { withoutEnlargement: true })
      .webp({ quality: 80 })
      .toBuffer(),
  ]);

  return { originalBuffer, mediumBuffer, thumbBuffer };
}

/**
 * S3에 이미지 업로드
 */
async function uploadToS3(key, buffer, contentType = 'image/webp') {
  await s3Client.send(new PutObjectCommand({
    Bucket: BUCKET,
    Key: key,
    Body: buffer,
    ContentType: contentType,
  }));
  return `${PUBLIC_URL}/${BUCKET}/${key}`;
}

/**
 * S3에서 이미지 삭제
 */
async function deleteFromS3(key) {
  try {
    await s3Client.send(new DeleteObjectCommand({
      Bucket: BUCKET,
      Key: key,
    }));
  } catch (err) {
    console.error(`S3 삭제 오류 (${key}):`, err.message);
  }
}

/**
 * 멤버 프로필 이미지 업로드
 * @param {string} name - 멤버 이름
 * @param {Buffer} buffer - 이미지 버퍼
 * @returns {Promise<{originalUrl: string, mediumUrl: string, thumbUrl: string}>}
 */
export async function uploadMemberImage(name, buffer) {
  const { originalBuffer, mediumBuffer, thumbBuffer } = await processImage(buffer);

  const basePath = `member/${name}`;
  const filename = `${name}.webp`;

  // 병렬 업로드
  const [originalUrl, mediumUrl, thumbUrl] = await Promise.all([
    uploadToS3(`${basePath}/original/${filename}`, originalBuffer),
    uploadToS3(`${basePath}/medium_800/${filename}`, mediumBuffer),
    uploadToS3(`${basePath}/thumb_400/${filename}`, thumbBuffer),
  ]);

  return { originalUrl, mediumUrl, thumbUrl };
}

/**
 * 멤버 프로필 이미지 삭제
 * @param {string} name - 멤버 이름
 */
export async function deleteMemberImage(name) {
  const basePath = `member/${name}`;
  const filename = `${name}.webp`;
  const sizes = ['original', 'medium_800', 'thumb_400'];

  await Promise.all(
    sizes.map(size => deleteFromS3(`${basePath}/${size}/${filename}`))
  );
}