import { ref, shallowRef, onBeforeUnmount, onDeactivated, onActivated, watch } from 'vue'
import { useUserStore } from '@/store/modules/user'
import { gatewayError, requireGatewayAccess } from '@/utils/business/gateway'
import { pollingScope } from '@/utils/business/pollingScheduler'

export function useSchedulerRequest<T>(request: () => Promise<T>, allowed: () => boolean) {
  const user = useUserStore()
  const data = shallowRef<T | null>(null),
    loading = ref(false),
    error = ref('')
  let sequence = 0,
    active = true
  function clear() {
    ++sequence
    data.value = null
    loading.value = false
    error.value = ''
  }
  async function load() {
    if (!active) return
    const current = ++sequence,
      scope = pollingScope(user)
    loading.value = true
    error.value = ''
    data.value = null
    try {
      requireGatewayAccess(allowed())
      const result = await request()
      if (active && current === sequence && scope === pollingScope(user) && allowed())
        data.value = result
    } catch (cause) {
      if (active && current === sequence) {
        data.value = null
        error.value = gatewayError(cause)
      }
    } finally {
      if (current === sequence) loading.value = false
    }
  }
  watch(() => [pollingScope(user), allowed()], clear, { flush: 'sync' })
  onDeactivated(() => {
    active = false
    clear()
  })
  onActivated(() => {
    if (!active) {
      active = true
      void load()
    }
  })
  onBeforeUnmount(() => {
    active = false
    clear()
  })
  return { data, loading, error, load }
}