const { Effect, EffectResultPromise, EffectResultWrapper } = require('./effect-common')

module.exports = function race(...effects) {
  let index = -1
  let temps
  let p
  return Effect(() => {
    const racePromise = EffectResultPromise()

    temps = effects.map((effect, idx) => {
      const preResult = effect.effectFunc()
      const p = preResult.resultPromise.then(ret => {
        temps[idx].result = ret
        if (ret.succFlag == 0 && index == -1) {
          index = idx
          racePromise.succ(ret.result, ret.succResultParams, ret.failResultParams)
          temps.filter((t, i) => i != idx).forEach(t => t.cancel())
        }
      })
      return {
        effect,
        p,
        cancel: preResult.cancel
      }
    })

    p = Promise.all(temps.map(t => t.p)).then(() => {
      const flag = temps.map(t => t.result.succFlag != 0).reduce((s, e) => s && e)
      if (flag) {
        racePromise.fail(undefined, new Error('all effects fail'))
      }
    })

    return EffectResultWrapper(racePromise, () => { })
  }
    , () => p.then(() => temps.forEach((t, idx) => idx == index ? t.effect.succFunc(t.result.succResultParams) : t.effect.failFunc(t.result.failResultParams)))
    , () => p.then(temps.forEach(t => t.result.failFunc(t.result.failResultParams))))
}