import { ref, watch, onUnmounted } from 'vue'
import type { Ref } from 'vue'
import { AUTO_REFRESH_INTERVAL_S } from '../data/constants'

export function useAutoRefresh(fetchFn: () => Promise<void>, enabled: Ref<boolean>) {
  const countdown = ref(AUTO_REFRESH_INTERVAL_S)

  let intervalId: ReturnType<typeof setInterval> | null = null
  let tickId: ReturnType<typeof setInterval> | null = null

  function startRefresh() {
    stopRefresh()
    countdown.value = AUTO_REFRESH_INTERVAL_S

    // Countdown tick every second
    tickId = setInterval(() => {
      countdown.value = Math.max(0, countdown.value - 1)
    }, 1000)

    // Fetch every interval
    intervalId = setInterval(async () => {
      await fetchFn()
      countdown.value = AUTO_REFRESH_INTERVAL_S
    }, AUTO_REFRESH_INTERVAL_S * 1000)
  }

  function stopRefresh() {
    if (intervalId !== null) {
      clearInterval(intervalId)
      intervalId = null
    }
    if (tickId !== null) {
      clearInterval(tickId)
      tickId = null
    }
  }

  watch(
    enabled,
    (val) => {
      if (val) {
        startRefresh()
      } else {
        stopRefresh()
      }
    },
    { immediate: true }
  )

  onUnmounted(() => {
    stopRefresh()
  })

  return { countdown }
}