export const loadingStatus$: BehaviorSubject<boolean> = new BehaviorSubject<boolean>(false)

axios.interceptors.request.use(
 (config: any) => {
  loadingStatus$.next(true)
  return config
 },
 (error: any) => {
  return Promise.reject(error)
 },
)

axios.interceptors.response.use(
 (response: any) => {
  loadingStatus$.next(false)
  return response.data
 },
 (error: any) => {
  loadingStatus$.next(false)
  wx.showToast({ title: 'something wrong happened, please try it later' })
  return Promise.reject(error)
 },
)

let timer: any = 0
loadingStatus$
.pipe(
 pairwise(),
 filter((res: Array<boolean>) => {
  if (res[0] !== res[1]) {
   return true
  } else {
   return false
  }
 }),
 map((res: Array<boolean>) => {
  return res[1]
 }),
)
.subscribe((res: boolean) => {
 // once changed, value must be distinct
 if (timer === 0) {
  timer = setTimeout(() => {
   wx.showLoading({ title: 'loading...' })
  }, 1000)
 } else {
  clearTimeout(timer)
  timer=0
  wx.hideLoading()
 }
})