import { ref } from 'vue'

import { onHide, onShow, onUnload } from '@dcloudio/uni-app'

import { getLocation, type LocationResult } from '@/lib/location'

import { getDictTypeApi } from '@/services/modules/common'

import { DEFAULT_VISIT_RANGE_RADIUS } from '../taskVisit.config'
import type { VisitLocationStatus } from '../types'

const LOCATION_POLL_INTERVAL = 5 * 60_000

export const useVisitLocation = () => {
  const currentLocation = ref<LocationResult | null>(null)
  const locationStatus = ref<VisitLocationStatus>('idle')
  const rangeRadius = ref(DEFAULT_VISIT_RANGE_RADIUS)

  let locationTimer: ReturnType<typeof setInterval> | undefined
  let locating = false

  const stopLocationPolling = () => {
    if (!locationTimer) return

    clearInterval(locationTimer)
    locationTimer = undefined
  }

  const refreshCurrentLocation = async () => {
    if (locating) return

    locating = true
    if (!currentLocation.value) {
      locationStatus.value = 'locating'
    }

    try {
      const location = await getLocation()

      if (!isValidLocation(location)) {
        throw new Error('Invalid location result')
      }

      currentLocation.value = location
      locationStatus.value = 'ready'
    } catch {
      locationStatus.value = 'error'

      // 授权失败后暂停自动轮询，避免反复唤起授权提示；用户可手动重试。
      stopLocationPolling()
    } finally {
      locating = false
    }
  }

  const startLocationPolling = () => {
    stopLocationPolling()
    void refreshCurrentLocation()

    locationTimer = setInterval(() => {
      void refreshCurrentLocation()
    }, LOCATION_POLL_INTERVAL)
  }

  const loadRangeRadius = async () => {
    try {
      const res = await getDictTypeApi('point_jwd')
      const radius = Number(res.data?.[0]?.value)

      if (Number.isFinite(radius) && radius > 0) {
        rangeRadius.value = radius
      }
    } catch {
      rangeRadius.value = DEFAULT_VISIT_RANGE_RADIUS
    }
  }

  onShow(() => {
    startLocationPolling()
    void loadRangeRadius()
  })
  onHide(stopLocationPolling)
  onUnload(stopLocationPolling)

  return {
    currentLocation,
    locationStatus,
    rangeRadius,
    refreshCurrentLocation: startLocationPolling,
  }
}

const isValidLocation = (location: LocationResult) => {
  return (
    Number.isFinite(location.latitude) &&
    Number.isFinite(location.longitude) &&
    !(location.latitude === 0 && location.longitude === 0)
  )
}