//监听文件变化
document.getElementById('file').onchange = function() {
                    let file = this.files[0];
                    let type = file.type
                    //初始化文件上传
                    initUploadObj(that, file.name, file, 'image', function(res) {
                        if (res.success) {
                            that.$message.success(res.msg)
                        } else {
                            that.$message.warning(res.msg)
                        }
                    })
                }

/**
 * 初始化上传文件对象
 * @param {object} Vue
 * @param {string} fileName 文件名
 * @param {object} file 上传的文件流及文件类型 名称相关信息
 * @param {Array} 允许上传的文件类型
 * @param {function} uploadStatusCallbalck
 * @return {function} 返回回调函数
 */
export const initUploadObj = function (Vue,fileName,file,type,uploadStatusCallbalck) {
  let fileInfo = {
    file_name: fileName,
    media_type: 2,
    media_sub_type: 0,
    size_of_bytes: 122,
    file_expired_type: 'permanent',
  };
  //前端做文件类型限制
  if(type == 'image'){
    type = ['.jpg','.gif','.jpeg','.bmp','.png']
  }
  if(type == 'excel'){
    type = ['.xlsx']
  }
  let fileType =file.name ? file.name.substring(file.name.lastIndexOf(".")).toLowerCase() : ''; 
  if (!!type && type.indexOf (fileType) < 0) {
    uploadStatusCallbalck ({success: false, msg: '请上传正确的'+type+'文件格式!'});
    return;
  }
  var cos = new COS ({
    getAuthorization: function (options, callback) {
      let singleInfo = Vue.$store.state.fileToken;
      callback ({
        TmpSecretId: singleInfo.tmpSecretId,
        TmpSecretKey: singleInfo.tmpSecretKey,
        XCosSecurityToken: singleInfo.sessionToken,
        ExpiredTime: singleInfo.expiredTime,
      });
    },
  });
  fileInfo.file_name = file.name;
  //获取文件上传密钥
  getFileToken (Vue, fileInfo, cos, file, uploadStatusCallbalck);
};

function getFileToken (Vue, fileInfo, cos, file, uploadStatusCallbalck) {
  let url = process.env.VUE_APP_URL + '/file/secretid';
  if (!file) return;
  // 异步获取临时密钥
  axios
    .get (url)
    .then (function (res) {
      if (res.data.code == 100000) {
        //获取的临时秘钥存储在vuex中
        Vue.$store.commit ('UPDATE_FILE_INFO', res.data.data);
        uploadFile (cos, file, res.data.data, uploadStatusCallbalck);
      } else {
        uploadStatusCallbalck ({success: false, msg: '获取文件秘钥失败!'});
      }
    })
    .catch (function (err) {
      uploadStatusCallbalck ({success: false, msg: '获取文件秘钥接口出错!'});
    });
}

/**
 * @method uploadFile
 * @param {object} cos
 */
function uploadFile (cos, file, signInfo, callback) {
  cos.putObject (
    {
      Bucket: process.env.VUE_APP_BUCKET,
      Region: 'ap-shanghai',
      Key: signInfo.fileId,
      Body: file,
      onHashProgress: function (progressData) {
        console.log ('校验中', JSON.stringify (progressData));
      },
      onProgress: function (progressData) {
        console.log ('上传中', JSON.stringify (progressData));
      },
    },
    function (err, data) {
      if (err) {
        console.log (err);
        callback ({success: false, msg: '文件上传失败!'});
        return;
      }
      callback ({success: true, msg: '上传成功!', data: data, signInfo: signInfo});
    }
  );
}