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.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 javax.servlet.ServletContext;
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.Date;
import java.util.List;
import java.util.UUID;

/**
 * 文件服务类
 * @author WWW
 */
@Service
public class FileService {
    @Autowired
    PathHelper pathHelper;

    @Autowired
    AttachService attachService;

    private final static double D92 = 92;

    private final static long ONE_DAY = 24 * 60 * 60 * 1000;

    private final static long SIZE_MAX = 1024 * 1024 * 1024 * 1024;

    private final static long FILE_SIZE_MAX = 256 * 1024 * 1024 * 1024;

    private final static Log log = LogFactory.getLog(FileService.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.getConfig().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 void uploadData(HttpServletRequest req, HttpServletResponse res) {
        try {
            // 处理中文乱码问题
            req.setCharacterEncoding("utf-8");
            res.setContentType("text/html;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);

            // 限制上传的总文件大小
            sfu.setSizeMax(SIZE_MAX);
            // 限制单个文件的大小
            sfu.setFileSizeMax(FILE_SIZE_MAX);
            // 设置编码方式
            sfu.setHeaderEncoding("utf-8");

            // list容器用来保存表单中的所有数据信息
            List<FileItem> items = sfu.parseRequest(ctx);
            // 遍历容器，处理解析的内容：一个处理普通表单域，一个处理文件的表单域
            for (FileItem item : items) {
                if (item.isFormField()) {
                    handleFormField(item);
                } else {
                    handleFileField(item, req);
                }
            }
        } catch (Exception ex) {
            log.error(ex.getMessage() + ex.getStackTrace() + "\n");
        }
    }

    /**
     * 处理 普通数据项
     *
     * @param item
     */
    private void handleFormField(FileItem item) {
        // 获取 普通数据项中的 name值
        String fieldName = item.getFieldName();

        // 获取 普通数据项中的 value值
        String value = "";
        try {
            // 以 utf-8的编码格式来解析 value值
            value = item.getString("utf-8");
        } catch (Exception ex) {
            log.error(ex.getMessage() + ex.getStackTrace() + "\n");
        }

        // 输出到控制台
        System.out.println("fieldName:" + fieldName + "--value:" + value);
    }

    /**
     * 处理 文件数据项
     *
     * @param item
     */
    private void handleFileField(FileItem item, HttpServletRequest req) {
        // 获取 文件数据项中的 文件名
        String fileName = item.getName();

        // 判断 此文件的文件名是否合法
        if (fileName == null || "".equals(fileName)) {
            return;
        }

        // 控制只能上传图片
        String img = "image";
        if (!item.getContentType().startsWith(img)) {
            return;
        }

        // 将文件信息输出到控制台:文件名+文件大小
        System.out.println("fileName:" + fileName);
        System.out.println("fileSize:" + item.getSize());

        // 获取 当前项目下的 /files 目录的绝对位置
        ServletContext ctx = req.getSession().getServletContext();
        String path = ctx.getRealPath("/files");

        // 创建 file对象
        File file = new File(path);
        if (!file.exists()) {
            // 创建目录
            file.mkdir();
        }

        // 将文件保存到服务器上（UUID是通用唯一标识码）
        try {
            item.write(new File(file.toString(), UUID.randomUUID() + "_" + fileName));
        } catch (Exception e) {
            e.printStackTrace();
        }
    }


    /**
     * 获取临时路径
     */
    public String getTempPath() {
        String tempName = FileHelper.getTempPath();
        String tempPath = pathHelper.getConfig().getTempPath();
        String path = tempPath + File.separator + tempName;

        File file = new File(path);
        if (!file.exists() && !file.isDirectory()) {
            file.mkdirs();
        }

        double ran = Math.random() * 99;
        if (ran > D92) {
            deleteOldPath();
        }

        return path;
    }

    public void deleteOldPath() {
        try {
            Long time = System.currentTimeMillis();
            for (int i = 1, c = 30; i < c; i++) {
                Date date = new Date(time - i * ONE_DAY);
                String str = StringHelper.YMD__FORMAT.format(date);

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