package com.lf.server.service.all;

import com.alibaba.fastjson.JSON;
import com.lf.server.controller.all.BaseController;
import com.lf.server.entity.all.HttpStatus;
import com.lf.server.entity.all.ResponseMsg;
import com.lf.server.entity.all.SettingData;
import com.lf.server.entity.sys.AttachEntity;
import com.lf.server.entity.sys.UserEntity;
import com.lf.server.helper.FileHelper;
import com.lf.server.helper.PathHelper;
import com.lf.server.helper.StringHelper;
import com.lf.server.helper.WebHelper;
import com.lf.server.service.sys.AttachService;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.net.URLEncoder;

/**
 * 上传服务类
 * @author WWW
 */
@Service
public class UploadService {
    @Autowired
    PathHelper pathHelper;

    @Autowired
    AttachService attachService;

    private final static Log log = LogFactory.getLog(UploadService.class);

    private static final String NO_FILE = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.NOT_FOUND, "文件找不到"));

    /**
     * 上传文件
     */
    public ResponseMsg<String> upload(UserEntity ue, String tab, MultipartFile file, BaseController ctrl) {
        try {
            if (file == null && file.isEmpty()) {
                return ctrl.fail("文件上传为空", null);
            }
            if (file.getSize() > SettingData.MAX_FILE_SIZE) {
                return ctrl.fail(String.format("文件大于 %d MB", SettingData.MAX_FILE_SIZE / 1024 / 1024), null);
            }

            // 传输文件
            String oldName = file.getOriginalFilename();
            String filePath = pathHelper.getTempPath(ue.getId()) + File.separator + oldName;
            File newFile = new File(filePath);
            file.transferTo(newFile);
            double sizes = FileHelper.sizeToMb(file.getSize());

            // 获取MD5
            String md5 = FileHelper.getFileMd5(filePath);
            AttachEntity entity = attachService.selectByGuid(md5);
            if (entity != null) {
                newFile.delete();
                return ctrl.success("文件已存在", md5);
            }

            AttachEntity ae = getAttachEntity(ue, tab, oldName, md5, sizes);
            String targetPath = pathHelper.getConfig().getUploadPath() + File.separator + ae.getPath();
            newFile.renameTo(new File(targetPath));

            int rows = attachService.insert(ae);

            return rows > 0 ? ctrl.success(md5) : ctrl.fail("保存文件失败", null);
        } catch (Exception ex) {
            return ctrl.fail(ex.getMessage(), null);
        }
   }

    /**
     * 获取附件实体类
     */
    protected AttachEntity getAttachEntity(UserEntity ue, String tab, String oldName, String md5, double sizes) {
        AttachEntity entity = new AttachEntity();
        entity.setName(oldName);
        entity.setTab(tab);
        entity.setGuid(md5);
        String subPath = PathHelper.getUploadPath() + File.separator + md5;
        entity.setPath(subPath);
        entity.setSizes(sizes);
        if (ue != null) {
            entity.setCreateUser(ue.getId());
        }

        return entity;
    }

    /**
     * 下载文件
     */
    public void download(String guid, HttpServletResponse res) {
        try {
            if (StringHelper.isEmpty(guid)) {
                WebHelper.write2Page(res, NO_FILE);
                return;
            }

            AttachEntity entity = attachService.selectByGuid(guid);
            if (entity == null) {
                WebHelper.write2Page(res, NO_FILE);
                return;
            }

            setDownloadResponse(entity, res);
            String filePath = pathHelper.getConfig().getUploadPath() + File.separator + entity.getPath();

            // 通过response对象，获取到输出流
            ServletOutputStream outputStream = res.getOutputStream();
            // 定义输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(filePath);

            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1) {
                // 通过输入流读取文件数据，然后通过上述的输出流写回浏览器
                outputStream.write(bytes, 0, len);
                outputStream.flush();
            }

            // 关闭资源
            outputStream.close();
            fileInputStream.close();
        } catch (Exception ex) {
            try {
                String msg = JSON.toJSONString(new ResponseMsg<String>(HttpStatus.ERROR, "文件下载出错"));
                WebHelper.write2Page(res, msg);
            } catch (Exception e) {
                log.error(e.getMessage(), e);
            }
            log.error(ex.getMessage(), ex);
        }
    }

    /**
     * 设置下载响应信息
     */
    private void setDownloadResponse(AttachEntity entity, HttpServletResponse res) throws IOException {
        String fileName = URLEncoder.encode(entity.getName(), "UTF-8");

        // 设置响应头中文件的下载方式为附件方式，以及设置文件名
        res.setHeader("Content-Disposition", "attachment; filename=" + fileName);
        // 设置响应头的编码格式为UTF-8
        res.setCharacterEncoding("UTF-8");

        // 通过response对象设置响应数据格式(如："text/plain; charset=utf-8")
        String ext = FileHelper.getExtension(entity.getName());
        String mime = FileHelper.getMime(ext);
        res.setContentType(mime);
    }
}