import { useCallback, useEffect, useRef, useState } from 'react'

import type { LatLng } from '@/types/api'

function geolocationErrorMessage(error: GeolocationPositionError): string {
  switch (error.code) {
    case error.PERMISSION_DENIED:
      return 'Location access denied. Enable it to view nearby pings.'
    case error.POSITION_UNAVAILABLE:
      return 'Unable to determine your position. Try again.'
    case error.TIMEOUT:
      return 'Timed out while fetching your location.'
    default:
      return 'Failed to retrieve your location.'
  }
}

export function useUserLocation() {
  const [location, setLocation] = useState<LatLng | null>(null)
  const [error, setError] = useState<string | null>(null)
  const [isRequesting, setIsRequesting] = useState<boolean>(false)
  const watchIdRef = useRef<number | null>(null)

  const clearWatch = useCallback(() => {
    if (typeof navigator === 'undefined' || !navigator.geolocation) {
      return
    }
    if (watchIdRef.current !== null) {
      navigator.geolocation.clearWatch(watchIdRef.current)
      watchIdRef.current = null
    }
  }, [])

  const start = useCallback(() => {
    if (typeof navigator === 'undefined' || !navigator.geolocation) {
      setError('Geolocation is not supported in this browser.')
      setIsRequesting(false)
      return
    }

    clearWatch()
    setIsRequesting(true)
    setError(null)

    navigator.geolocation.getCurrentPosition(
      (position) => {
        setLocation({ lat: position.coords.latitude, lng: position.coords.longitude })
        setIsRequesting(false)
        setError(null)
      },
      (geoError) => {
        setError(geolocationErrorMessage(geoError))
        setIsRequesting(false)
      },
      { enableHighAccuracy: true, timeout: 10000 },
    )

    const watchId = navigator.geolocation.watchPosition(
      (position) => {
        setLocation({ lat: position.coords.latitude, lng: position.coords.longitude })
        setError(null)
        setIsRequesting(false)
      },
      (geoError) => {
        setError(geolocationErrorMessage(geoError))
        setIsRequesting(false)
      },
      { enableHighAccuracy: true, maximumAge: 15000, timeout: 10000 },
    )

    watchIdRef.current = watchId
  }, [clearWatch])

  useEffect(() => {
    start()

    return () => {
      clearWatch()
    }
  }, [clearWatch, start])

  return {
    location,
    error,
    isRequesting,
    refresh: start,
  }
}