package com.vci.ubcs.resource.utils;

import com.vci.ubcs.resource.bo.FileObjectBO;
import lombok.extern.slf4j.Slf4j;
import org.apache.commons.io.IOUtils;
import org.springframework.http.MediaType;
import org.springframework.http.MediaTypeFactory;

import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletResponse;
import java.io.FileInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.net.URLEncoder;

/**
 * 下载文件的工具
 * @author weidy
 * @date 2023/6/9
 */
@Slf4j
public class FileDownloadUtil {

    /**
     * 下载文件
     * @param response 响应对象
     * @param fileObjectBO 文件的信息，包含文件的输入流
     * @throws IOException 下载异常会抛出
     */
    public static void downloadFile(HttpServletResponse response, FileObjectBO fileObjectBO) throws IOException {
        downloadFile(response,fileObjectBO,true);
    }

    /**
     * 下载文件
     * @param response 响应对象
     * @param fileObjectBO 文件的信息，包含文件的输入流
     * @param closeInputStream 是否关闭流
     * @throws IOException 下载出错的时候抛出异常
     */
    public static void downloadFile(HttpServletResponse response, FileObjectBO fileObjectBO,boolean closeInputStream) throws IOException {
        MediaType mediaType = MediaTypeFactory.getMediaType(fileObjectBO.getBucketName() + "." + fileObjectBO.getFileExtension()).orElse(MediaType.APPLICATION_OCTET_STREAM);
        // 设置强制下载不打开
        response.setContentType(mediaType.toString()+";application/force-download;charset=UTF-8");
        try{
            String fileName = URLEncoder.encode(fileObjectBO.getName() + "." + fileObjectBO.getFileExtension(), "UTF8");
            response.addHeader("Content-Disposition", "attachment;filename="+ fileName+ ";filename*=utf-8''");
        }catch(Exception e){
            if(log.isErrorEnabled()){
                log.error("设置文件的名称到响应流的时候出错",e);
            }
        }
        response.setCharacterEncoding("UTF-8");
        Cookie cookie = new Cookie("fileDownload", "true");
        cookie.setPath("/");
        response.addCookie(cookie);
		if(closeInputStream) {
			try (InputStream ins = (fileObjectBO.getInputStream() != null ? fileObjectBO.getInputStream() : new FileInputStream(fileObjectBO.getFileLocalPath()))) {
				IOUtils.copy(ins, response.getOutputStream());
			} catch (IOException e) {
				//有可能客户端的链接
				if (log.isErrorEnabled()) {
					log.error("写入文件到响应流出错", e);
				}
				throw e;
			}
		}else{
			try {
				InputStream ins = (fileObjectBO.getInputStream() != null ? fileObjectBO.getInputStream() : new FileInputStream(fileObjectBO.getFileLocalPath()));
				IOUtils.copy(ins, response.getOutputStream());
			} catch (IOException e) {
				//有可能客户端的链接
				if (log.isErrorEnabled()) {
					log.error("写入文件到响应流出错", e);
				}
				throw e;
			}
		}
    }
}