package umc.spring.file.service;

import com.amazonaws.AmazonServiceException;
import com.amazonaws.HttpMethod;
import com.amazonaws.services.s3.AmazonS3;
import com.amazonaws.services.s3.model.CannedAccessControlList;
import com.amazonaws.services.s3.model.GeneratePresignedUrlRequest;
import com.amazonaws.services.s3.model.ObjectMetadata;
import com.amazonaws.services.s3.model.PutObjectRequest;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import java.io.IOException;
import java.net.URL;
import java.net.URLDecoder;
import java.util.Date;

/* S3Service.java */
@Slf4j
@RequiredArgsConstructor
@Service
public class S3Service {

    @Value("${cloud.aws.s3.bucket}")
    private String bucket;

    private final AmazonS3 amazonS3;

    /* 1. 파일 업로드 */
    public String upload(MultipartFile multipartFile, String s3FileName) throws IOException {
        // 메타데이터 생성
        ObjectMetadata objMeta = new ObjectMetadata();
        objMeta.setContentLength(multipartFile.getInputStream().available());
        // putObject(버킷명, 파일명, 파일데이터, 메타데이터)로 S3에 객체 등록
        amazonS3.putObject(new PutObjectRequest(bucket, s3FileName, multipartFile.getInputStream(), objMeta)
                .withCannedAcl(CannedAccessControlList.PublicRead));
        // 등록된 객체의 url 반환 (decoder: url 안의 한글 or 특수문자 깨짐 방지)
        return URLDecoder.decode(amazonS3.getUrl(bucket, s3FileName).toString(), "utf-8");
    }

    /* 2. 파일 삭제 */
    public void delete (String keyName) {
        try {
            // deleteObject(버킷명, 키값)으로 객체 삭제
            amazonS3.deleteObject(bucket, keyName);
        } catch (AmazonServiceException e) {
            log.error(e.toString());
        }
    }

    /* 3. 파일의 presigned URL 반환 */
    public String getPresignedURL (String keyName) {
        String preSignedURL = "";
        // presigned URL이 유효하게 동작할 만료기한 설정 (2분)
        Date expiration = new Date();
        Long expTimeMillis = expiration.getTime();
        expTimeMillis += 1000 * 60 * 2;
        expiration.setTime(expTimeMillis);

        try {
            // presigned URL 발급
            GeneratePresignedUrlRequest generatePresignedUrlRequest = new GeneratePresignedUrlRequest(bucket, keyName)
                    .withMethod(HttpMethod.GET)
                    .withExpiration(expiration);
            URL url = amazonS3.generatePresignedUrl(generatePresignedUrlRequest);
            preSignedURL = url.toString();
        } catch (Exception e) {
            log.error(e.toString());
        }

        return preSignedURL;
    }
}