package com.casic.missiles.utils;


import org.apache.commons.lang3.StringUtils;

import javax.servlet.http.HttpServletResponse;
import java.io.*;
import java.net.URLEncoder;
import java.nio.charset.StandardCharsets;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

/**
 * @author zhouxuan
 * @since 2019/4/19
 */
public class ZipUtils {


    public static void batchDownloadFiles(String rootFileName, HttpServletResponse response,String localFileDir) {
        FileInputStream is = null;
        BufferedOutputStream out = null;
        String rootFilePath = rootFileName + ".zip";
        try {
            response.reset();
            response.setCharacterEncoding("UTF-8");
            response.setContentType("application/zip;charset=utf-8");
            response.setHeader("Content-Disposition", "attachment;filename=" + URLEncoder.encode(rootFilePath, StandardCharsets.UTF_8.name()));
            response.setHeader("Access-Control-Allow-Origin", "*");
            System.out.println(response.getHeader("Content-Disposition"));
            rootFilePath =zipFileCreator(localFileDir, rootFileName, rootFilePath);
            //开始下载
            is = new FileInputStream(new File(rootFilePath));
            out = new BufferedOutputStream(response.getOutputStream());
            byte[] buff = new byte[1024];
            int len = 0;
            while ((len = is.read(buff, 0, buff.length)) != -1) {
                out.write(buff, 0, len);
            }
            out.flush();
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (is != null) {
                try {
                    is.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            if (out != null) {
                try {
                    out.close();
                    if (StringUtils.isNotEmpty(rootFilePath)) {
                        new ZipUtils().zipFileDeletor(rootFilePath);
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }
    /**
     * 批量打包
     *
     * @param downloadPath 项目根目录
     * @return tempDir 文件保存绝对路径
     */
    public static String zipFileCreator(String downloadPath, String tempDir,String papersZipName) {
        ZipOutputStream out = null;
        try {
            //zip文件保存路径
            String zipPath = downloadPath  + papersZipName;
            String fileSaveRootPath=downloadPath+tempDir;
            File file = new File(fileSaveRootPath);
            File[] files = file.listFiles();
            out = new ZipOutputStream(new FileOutputStream(zipPath));
            //遍历jsonArray列表获取所有JSONObject对象
            for (int i = 0; i < files.length; i++) {
                //以论文标题为每个文件命名
                FileInputStream fis = new FileInputStream(fileSaveRootPath + File.separator + files[i].getName());
                out.putNextEntry(new ZipEntry(files[i].getName()));
                //写入压缩包
                int len;
                byte[] buffer = new byte[1024];
                while ((len = fis.read(buffer)) > 0) {
                    out.write(buffer, 0, len);
                }
                out.closeEntry();
                fis.close();
            }
            out.close();
            out.flush();
            return zipPath;
        } catch (Exception e) {
            e.printStackTrace();
        } finally {
            if (out != null) {
                try {
                    out.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
        return null;
    }

    /**
     * 批量打包
     *
     * @param zipPath zip路径
     * @return zip文件保存绝对路径
     */
    public void zipFileDeletor(String zipPath) {
        try {
            File zipFile=new File(zipPath);
            zipFile.delete();
        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}