const createFetch = (time, mess) => createEffect(
  (prop) => new Promise(
    r => setTimeout(
      () => r({mess, prop})
      , time
    )
  )
)

const gFx = createFetch(50, 'google')
const aFx = createFetch(100, 'amazon')
const yFx = createFetch(200, 'yan')

/*
fmap :: (a -> b) -> f a -> f b
(<$>) :: Functor f => (a -> b) -> f a -> f b infixl 4
(<&>) :: Functor f => f a -> (a -> b) -> f b infixl 1
(>>=)  :: m a -> (a -> m b) -> m b
(>>)   :: m a -> m b -> m b
return :: a -> m a
fail   :: String -> m a
*/
   
const queneA = (fxes) => {
  const push = createEvent()
  const replace = createEvent()
  const reset = createEvent()
  const $state = createStore([])
    .reset(reset) 
    .on(push, (s, p) => ([...s, p]))
   .on(replace, (s, p) => (
     s.map(f => f.id === p.id ? p.replacer(f) : f)
    ))
  
  fxes.forEach((fx, i) => {
   const setInFlightState = createEvent()
    const $inFlightState = createStore({ prev: 0, current: 0 })
     .on(setInFlightState, (s, p) => ({
        prev: s.current,
          current: p,
      }))
  
    fx.inFlight.watch(setInFlightState)
    
    $inFlightState.watch(s => {
      // init
      if (s.prev === 0 && s.current === 0) return
      // start event
      if (s.prev < s.current) {
       push({
          id: `${i}${s.current}`,fx,
          timeStart: Date.now(), timeEnd: null
        })
      }
      // done event
      if (s.prev > s.current) {
    replace({
          id: `${i}${s.prev}`,
          replacer: f => ({ ...f, timeEnd: Date.now() })
      })
      }
    })
  })
  
  // $state.watch(console.log.bind(null, 'state'))
  const allEvents = guard({
   source: $state,
    filter: fxe => fxe.length > 0
  })
  allEvents.watch(console.log.bind(null, 'allEvents'))
  
  const firstDone = allEvents
   .filter({
     fn: fxes => fxes.filter(f => f.timeEnd !== null).length === 1
   })
   .filterMap(fxes => fxes.find(f => f.timeEnd !== null))
  firstDone.watch(console.log.bind(null, 'firstDone'))
  
  const firstDoneData = guard({
   source: firstDone,
    filter: f => f,
    target: firstDone
  })

  const allDone = guard({
   source: allEvents,
    filter: fxe => fxe.every(f => f.timeEnd !== null)
  })
 allDone.watch(console.log.bind(null, 'allDone'))
 
  const lastDone = allDone.filterMap(
    fxes => fxes.reduce((pf, cf) => cf.timeEnd > pf.timeEnd ? cf : pf)
  )
  lastDone.watch(console.log.bind(null, 'lastDone'))
  
  console.log('fx', firstDoneData)
  
  // firstDoneData.doneData.watch(console.log.bind(null, 'kk'))
  
  return {
   quenue: $state,
    firstDone,
    firstDoneData: firstDone.fx,
    lastDone,
    allDone
  }
}

queneA([
  gFx, aFx, yFx
])

gFx(1)
gFx(2)
// gFx()
// aFx()

// setTimeout(() => {aFx()},  400)