const sharp = require('sharp');
const { S3Client } = require('@aws-sdk/client-s3');

const s3 = new S3Client();
exports.handler = async (event, context, callback) => { ---- ➊

➋

  const Bucket = event.Records[0].s3.bucket.name;
  const Key = decodeURIComponent(event.Records[0].s3.object.key);
  const filename = Key.split('/').at(-1);
  const ext = Key.split('.').at(-1).toLowerCase();
  const requiredFormat = ext === 'jpg' ? 'jpeg' : ext; // sharp에서는 jpg 대신 jpeg를 사용합니다
  console.log('name', filename, 'ext', ext);

 

  try {

➌

    const S3Object = await s3.getObject({ Bucket, Key }); // 버퍼로 가져오기
    console.log('original', s3Object.Body.length);

➍

    const resizedImage = await sharp(s3Object.Body) // 리사이징
      .resize(200, 200, { fit: 'inside' })
      .toFormat(requiredFormat)
      .toBuffer();ss

➎

    await s3.putObject({ // thumb 폴더에 저장
      Bucket,
      Key: `thumb/${filename}`,
      Body: resizedImage,
    });
    console.log('put', resizedImage.length);
    return callback(null, `thumb/${filename}`);

  } catch (error) {
    console.error(error);
    return callback(error);
  }
};