package com.lf.server.service.data;

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.ctrl.FileInfo;
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.codec.digest.DigestUtils;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.tomcat.util.http.fileupload.FileItem;
import org.apache.tomcat.util.http.fileupload.disk.DiskFileItemFactory;
import org.apache.tomcat.util.http.fileupload.servlet.ServletFileUpload;
import org.apache.tomcat.util.http.fileupload.servlet.ServletRequestContext;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import org.springframework.web.multipart.MultipartFile;
import org.springframework.web.multipart.support.StandardMultipartHttpServletRequest;

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

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

    @Autowired
    AttachService attachService;

    private final static Log log = LogFactory.getLog(UploaderService.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() + File.separator + oldName;
            File newFile = new File(filePath);
            file.transferTo(newFile);

            // 获取MD5
            String md5 = 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);
            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);
        }
    }

    private String getFileMd5(String filePath) throws IOException {
        FileInputStream fileStream = new FileInputStream(filePath);
        String md5 = DigestUtils.md5Hex(fileStream);
        fileStream.close();

        return md5;
    }

    protected AttachEntity getAttachEntity(UserEntity ue, String tab, String oldName, String md5) {
        AttachEntity entity = new AttachEntity();
        entity.setName(oldName);
        entity.setTab(tab);
        entity.setGuid(md5);
        String subPath = PathHelper.getUploadPath() + File.separator + md5;
        entity.setPath(subPath);
        if (ue != null) {
            entity.setCreateUser(ue.getId());
        }

        return entity;
    }

    /**
     * 下载文件
     */
    public void download(String guid, HttpServletRequest req, HttpServletResponse res, BaseController ctrl) {
        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.getStackTrace() + "\n");
            }
            log.error(ex.getMessage() + ex.getStackTrace() + "\n");
        }
    }

    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);
    }

    /**
     * 上传文件
     */
    public Object uploadData(HttpServletRequest request, HttpServletResponse res) throws Exception {
        StandardMultipartHttpServletRequest req = (StandardMultipartHttpServletRequest) request;
        req.setCharacterEncoding("utf-8");
        res.setContentType("application/json;charset=utf-8");

        Map<String, String> map = getParams(req);
        List<FileInfo> list = getFiles(req);

        return list.size();
    }

    private Map<String, String> getParams(StandardMultipartHttpServletRequest req) {
        Map<String, String> map = new HashMap<String, String>(3);

        Enumeration<String> enumeration = req.getParameterNames();
        while (enumeration.hasMoreElements()) {
            String key = enumeration.nextElement();
            String value = req.getParameter(key);
            map.put(key, value);
        }

        return map;
    }

    private List<FileInfo> getFiles(StandardMultipartHttpServletRequest req) throws Exception {
        List<FileInfo> list = new ArrayList<FileInfo>();

        String path = pathHelper.getTempPath();
        Iterator<String> iterator = req.getFileNames();
        while (iterator.hasNext()) {
            MultipartFile file = req.getFile(iterator.next());

            FileInfo fi = new FileInfo(file.getOriginalFilename());
            if (StringHelper.isEmpty(fi.getFileName())) {
                continue;
            }

            fi.setSize(file.getSize());
            fi.setPath(path + File.separator + fi.getFileName());
            file.transferTo(new File(fi.getPath()));

            list.add(fi);
        }

        return list;
    }

    public Object fileUpload(HttpServletRequest req, HttpServletResponse res) throws Exception {
        List<FileItem> items = getFileItem(req, res);

        return copeFileItems(items, req);
    }

    /**
     * 获取文件项
     */
    private List<FileItem> getFileItem(HttpServletRequest req, HttpServletResponse res) throws Exception {
        // 处理中文乱码问题
        req.setCharacterEncoding("utf-8");
        // text/html;charset=utf-8
        res.setContentType("application/json;charset=utf-8");

        // 检查请求是/否为multipart/form-data类型
        if (!ServletFileUpload.isMultipartContent(req)) {
            throw new RuntimeException("表单的enctype属性不是multipart/form-data类型");
        }

        // 创建上传所需要的两个对象：磁盘文件对象+文件上传对象
        DiskFileItemFactory factory = new DiskFileItemFactory();
        ServletFileUpload sfu = new ServletFileUpload(factory);
        ServletRequestContext ctx = new ServletRequestContext(req);

        // 设置编码方式
        sfu.setHeaderEncoding("utf-8");
        factory.setSizeThreshold(4096);

        // 获取表单中的所有数据信息
        List<FileItem> list = sfu.parseRequest(ctx);

        return list;
    }

    /**
     * 处理解析内容：处理普通表单域和文件表单域
     */
    private Object copeFileItems(List<FileItem> items, HttpServletRequest req) throws Exception {
        Map<String, String> map = new HashMap<String, String>(3);
        List<FileInfo> list = new ArrayList<FileInfo>();

        String path = pathHelper.getTempPath();
        for (FileItem item : items) {
            if (item.isFormField()) {
                String key = item.getFieldName();
                String value = item.getString("utf-8");
                map.put(key, value);
                continue;
            }

            FileInfo fi = copeFile(item, path, req);
            if (fi != null) {
                list.add(fi);
            }
        }

        return map;
    }

    /**
     * 处理文件
     */
    private FileInfo copeFile(FileItem item, String path, HttpServletRequest req) {
        try {
            // 获取文件名，判断是否合法
            FileInfo fi = new FileInfo(item.getName());
            if (StringHelper.isEmpty(fi.getFileName())) {
                return null;
            }

            fi.setSize(item.getSize());
            fi.setPath(path + File.separator + fi.getFileName());
            item.write(new File(fi.getPath()));

            return fi;
        } catch (Exception ex) {
            log.error(ex.getMessage() + ex.getStackTrace() + "\n");
            return null;
        }
    }
}