package com.gkhy.exam.common.utils;

import cn.hutool.core.date.DatePattern;
import cn.hutool.core.date.DateUtil;
import cn.hutool.core.lang.UUID;
import com.gkhy.exam.common.config.MinioConfig;
import io.minio.*;
import io.minio.http.Method;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.util.FastByteArrayOutputStream;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.util.Date;

@Component
public class MinioUtils {
    @Autowired
    private MinioClient minioClient;
    @Autowired
    private MinioConfig minioConfig;

    /**
     * 查看存储bucket是否存在
     * @return boolean
     */
    public Boolean bucketExists(String bucketName) {
        Boolean found;
        try {
            found = minioClient.bucketExists(BucketExistsArgs.builder().bucket(bucketName).build());
        } catch (Exception e) {
            e.printStackTrace();
            return false;
        }
        return found;
    }

    /**
     * 文件上传
     *
     * @param file 文件
     * @return Boolean
     */
    public String upload(MultipartFile file) {
        String originalFilename = file.getOriginalFilename();
        if (StringUtils.isBlank(originalFilename)){
            throw new RuntimeException();
        }
        String fileName = UUID.fastUUID() + originalFilename.substring(originalFilename.lastIndexOf("."));
        String objectName = DateUtil.format(new Date(), DatePattern.PURE_DATE_PATTERN) + "/" + fileName;
        try {
            PutObjectArgs objectArgs = PutObjectArgs.builder().bucket(minioConfig.getBucketName()).object(objectName)
                    .stream(file.getInputStream(), file.getSize(), -1).contentType(file.getContentType()).build();
            //文件名称相同会覆盖
            minioClient.putObject(objectArgs);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return objectName;
    }

    /**
     * 预览图片
     * @param fileName
     * @return
     */
    public String preview(String fileName){
        // 查看文件地址
        GetPresignedObjectUrlArgs build = new GetPresignedObjectUrlArgs().builder().bucket(minioConfig.getBucketName()).object(fileName).method(Method.GET).build();
        try {
            String url = minioClient.getPresignedObjectUrl(build);
            return url;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    /**
     * 文件下载
     * @param fileName 文件名称
     * @param res response
     * @return Boolean
     */
    public void download(String fileName, HttpServletResponse res) {
        GetObjectArgs objectArgs = GetObjectArgs.builder().bucket(minioConfig.getBucketName())
                .object(fileName).build();
        try (GetObjectResponse response = minioClient.getObject(objectArgs)){
            byte[] buf = new byte[1024];
            int len;
            try (FastByteArrayOutputStream os = new FastByteArrayOutputStream()){
                while ((len=response.read(buf))!=-1){
                    os.write(buf,0,len);
                }
                os.flush();
                byte[] bytes = os.toByteArray();
                res.setCharacterEncoding("utf-8");
                // 设置强制下载不打开
                // res.setContentType("application/force-download");
                res.addHeader("Content-Disposition", "attachment;fileName=" + fileName);
                try (ServletOutputStream stream = res.getOutputStream()){
                    stream.write(bytes);
                    stream.flush();
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}