class HttpCli {
  constructor() {
    this.cachemsg = [];
    this._needretry = false;
    this._retrycount = 3;
    this._retryms = 3000;
    this._runningcount = 0;
    this._maxrunning = 10;
  }

  httpGet(url, cbRes, cbErr) {
    return this.httpsend(url, null, cbRes, cbErr, 'GET');
  }

  httpPost(url, postdata, cbRes, cbErr) {
    return this.httpsend(url, postdata, cbRes, cbErr, 'POST');
  }

  httpsend(url, urldata, cbRes, cbErr, smethod, isretry, contentType, useWeb) {
    if (this._runningcount < this._maxrunning) {
      return this._httpsend(url, urldata, cbRes, cbErr, smethod, isretry, contentType, useWeb);
    } else {
      console.log('[http]running/max:' + this._runningcount + '/' + this._maxrunning);
      console.log('[http]url:' + url);
      if (!isretry) {
        let obj = {
          u: url,
          v: urldata,
          successcb: cbRes,
          errcb: cbErr
        };
        this.cachemsg.push(obj);
        return null;
      }
    }
  }

  _httpsend(url, urldata, cbRes, cbErr, smethod, isretry, contentType, useWeb) {
    if (typeof (wx) != 'undefined' && wx.request && !useWeb) {
      return this._wxRequest(url, urldata, cbRes, cbErr, smethod, isretry, contentType);
    } else if (typeof (XMLHttpRequest) != 'undefined') {
      return this._webRequest(url, urldata, cbRes, cbErr, smethod, isretry, contentType);
    }
    return null;
  }

  _wxRequest(url, urldata, cbRes, cbErr, smethod, isretry, contentType) {
    this._runningcount++;
    let self = this;
    var jsobj = urldata ? JSON.parse(urldata) : null;
    var ct = contentType || 'application/json';
    var xhr = wx.request({
      url: url,
      data: jsobj,
      method: smethod,
      header: {
        'content-type': ct,
        'Cache-Control': 'no-cache'
      },
      success: function (res) {
        console.log('[wx]request success!' + res.statusCode);
        if (res.statusCode >= 200 && res.statusCode < 400) {
          var restext = JSON.stringify(res.data);
          cbRes && cbRes(restext);
        } else {
          if (!isretry && self._needretry) {
            let obj = {
              u: url,
              v: urldata,
              successcb: cbRes,
              errcb: cbErr
            };
            self.cachemsg.push(obj);
          } else {
            cbErr && cbErr(res.statusCode, res.msg);
          }
        }
      },
      fail: function (res) {
        console.log('[wx]request fail!' + JSON.stringify(res));
        if (!isretry && self._needretry) {
          let obj = {
            u: url,
            v: urldata,
            successcb: cbRes,
            errcb: cbErr
          };
          self.cachemsg.push(obj);
        } else {
          cbErr && cbErr(-1, res.msg);
        }
        // cbErr && cbErr(-1, res.msg);
      },
      complete: function () {
        self._runningcount--;
        console.log('[wx]request complete!');
      }
    });
    return xhr;
  }

  _webRequest(url, urldata, cbRes, cbErr, smethod, isretry, contentType) {
    this._runningcount++;
    let self = this;
    url += url.indexOf('?') >= 0 ? '&__t=' + new Date().getTime() : '?__t=' + Date.now();
    var xhr = new XMLHttpRequest();
    xhr.onreadystatechange = function () {
      if (xhr.readyState == 4) {
        self._runningcount--;
        if (xhr.status >= 200 && xhr.status < 400) {
          var response = xhr.responseText;
          cbRes && cbRes(response);
        } else {
          if (!isretry && self._needretry) {
            let obj = {
              u: url,
              v: urldata,
              successcb: cbRes,
              errcb: cbErr,
              contentType: contentType
            };
            self.cachemsg.push(obj);
          } else {
            cbErr && cbErr(xhr.status, xhr.statusText);
          }
        }
      }
    };
    // xhr.onabort = function(){
    //     self._runningcount--;
    // };
    xhr.onerror = function () {
      console.log('xhr.onerror');
      self._runningcount--;
    };
    xhr.open(smethod, url, true);
    (contentType) && xhr.setRequestHeader('content-type', contentType);
    xhr.send(urldata);
    return xhr;
  }

  _retry() {
    if (this.cachemsg.length > 0) {
      this.cachemsg.forEach(element => {
        let obj = element;
        if (obj.retrying) {
          return;
        }
        let bneedretry = false;
        if (!obj.retry_count) {
          obj.retry_count = 1;
          obj.passtime = 0;
        }
        obj.passtime += this._retryms;
        bneedretry = (obj.passtime >= obj.retry_count * this._retryms);

        if (bneedretry && !obj.retrying) {
          obj.retrying = true;
          let method = obj.v ? 'POST' : 'GET';
          this.httpsend(obj.u, obj.v, (restext) => {
            obj.successcb && obj.successcb(restext);
            let idx = this.cachemsg.findIndex((element) => {
              return element == obj;
            });
            if (idx != -1) {
              this.cachemsg.splice(idx, 1);
            }
          }, (errcode, errmsg) => {
            obj.retrying = false;
            obj.passtime = 0;
            obj.retry_count++;
            if (obj.retry_count >= this._retrycount) {
              obj.errcb && obj.errcb(errcode, errmsg);
              let idx = this.cachemsg.findIndex((element) => {
                return element == obj;
              });
              if (idx != -1) {
                this.cachemsg.splice(idx, 1);
              }
            }
          }, method, true, obj.contentType);
        }

      });
    }
  }

  setRetryCount(count) {
    this.retrycount = count;
  }

  setRetryInterval(millsec) {
    if (millsec != this._retryms) {
      this._retryms = millsec;
      if (this._retry_tid) {
        clearInterval(this._retry_tid);
        this._retry_tid = 0;
      }
    }
    if (!this._retry_tid) {
      this._retry_tid = setInterval(this._retry.bind(this), this._retryms);
    }
  }

  setNeedRetry(needretry) {
    this._needretry = needretry;
  }
}

module.exports = HttpCli;