package com.yuchen.saas.park.service.pull.untils;

import com.google.api.client.util.Base64;
import org.springframework.web.multipart.MultipartFile;

import java.io.*;

/**
 * @author 吕海泉
 * @create 2021/1/1 15:19
 */
public  class BASE64DecodedMultipartFile implements MultipartFile {

    private final byte[] imgContent;

    private final String header;


    public BASE64DecodedMultipartFile(byte[] imgContent, String header) {

        this.imgContent = imgContent;

        this.header = header.split(";")[0];

    }


    @Override

    public String getName() {
        return System.currentTimeMillis() + Math.random() + "." + header.split("/")[1];

    }


    @Override

    public String getOriginalFilename() {
        return System.currentTimeMillis() + (int) Math.random() * 10000 + "." + header.split("/")[1];

    }


    @Override

    public String getContentType() {
        return header.split(":")[1];

    }


    @Override

    public boolean isEmpty() {

        return imgContent == null || imgContent.length == 0;

    }


    @Override

    public long getSize() {

        return imgContent.length;

    }


    @Override

    public byte[] getBytes() throws IOException {

        return imgContent;

    }


    @Override

    public InputStream getInputStream() throws IOException {

        return new ByteArrayInputStream(imgContent);

    }


    @Override

    public void transferTo(File dest) throws IOException, IllegalStateException {

        new FileOutputStream(dest).write(imgContent);

    }

    public static MultipartFile base64ToMultipart(String base64) {
        String[] baseStrs = base64.split(",");
        byte[] b = new byte[0];
        b = Base64.decodeBase64(baseStrs[1]);

        for(int i = 0; i < b.length; ++i) {
            if (b[i] < 0) {
                b[i] += 256;
            }
        }

        return new BASE64DecodedMultipartFile(b, baseStrs[0]);
    }
}
