const path = require('path');
const fs = require('fs');
const formidable = require('formidable')
const {handle} = require("../tools/handle_cjs");
const result = require("../tools/result");
const log = require("../logger").logger("uploadMiddleware","info");


module.exports = function (config){
  if(!config){
    throw new Error('config is undefined');
  }
  let _config = {
    tmp: config.tmp || './tmp',
    maxFileSize: config.maxFileSize || (1024*1024*2),// 默认2mb
  };

  return async function upload(req,res,next){
    log.info(`[文件上传] 开始接收上传文件`)
    let form = formidable.formidable({
      uploadDir: _config.tmp,
      multiples: true,
      keepExtensions: true,
      type: true,
      maxFileSize: _config.maxFileSize,
      filename(_fileName, _extName) {
        // console.log('---------')
        // console.log(_fileName+'.'+_extName);
        // console.log('---------')
        let time = new Date();
        // 生成随机数
        let random = Math.floor(Math.random() * 1000);
        // 生成随机字符
        let str = 'abcdefghijklmnopqrstuvwxyz';
        let randomStr = '';
        let fileName = '';
        for (let i = 0; i < 5; i++) {
          randomStr += str.charAt(Math.floor(Math.random() * str.length));
        }
        fileName = `${time.getTime()}-${random}-${randomStr}-${_fileName}${_extName}`;
        // // 随机从fileName中抽取2-6个字符添加至随机位置
        // let randomIndex = Math.floor(Math.random() * (fileName.length - 2)) + 1;
        // let randomLength = Math.floor(Math.random() * 5) + 2;
        // let randomStr2 = '';
        // for (let i = 0; i < randomLength; i++) {
        //   randomStr2 += str.charAt(Math.floor(Math.random() * str.length));
        // }
        // fileName = fileName.slice(0, randomIndex) + randomStr2 + fileName.slice(randomIndex);
        return fileName;
      }
    });
    let allFile = [];
    let [err] = await handle(fs.promises.mkdir(_config.tmp));
    if(!err){
      // res.status(500);
      console.log(err);
      log.info(`[文件上传] 无法存储文件 ${err.message}`);
      result.ServerError(res, err, `无法存储文件 ${err.message}`);
      return;
    }
    await form.on('progress', function (bytesReceived, bytesExpected) { //在控制台打印文件上传进度
      let progressInfo = {
        value: bytesReceived, //当前进度
        total: bytesExpected //总进度
      };
      let bar_progress = Math.floor((progressInfo.value / progressInfo.total) * 100);
      // console.log(`当前进度: ${bar_progress}`);
    }).parse(req, function (err, fields, files) {
      if (err) {
        // res.status(500);
        log.info(`[文件上传] 文件上传失败 ${err.message}`);
        result.ServerError(res, err, `文件上传失败 ${err.message}`);
      } else {
        req.files = files;
        req.body = fields;
        next();
      }
    })
  }
};