import React, { createContext, useContext, useEffect, useRef } from 'react'
import { useLocation } from '@tanstack/react-router'
import { EventBus, REFRESH_EVENT } from './event-bus'
import { getQueryClient } from './query-client'

// Web port of packages/ui refresh-context + useManualRefresh +
// useMarkDataFetchers + useFocusCallback. Navigation focus (expo) is
// approximated with route-pathname changes; manual refresh uses the bus.

const RefreshContext = createContext<{ refreshAll: () => void } | null>(null)

export const RefreshProvider: React.FC<{ children: React.ReactNode }> = ({ children }) => {
  const refreshAll = () => {
    getQueryClient().invalidateQueries()
    EventBus.emit(REFRESH_EVENT)
  }
  return <RefreshContext.Provider value={{ refreshAll }}>{children}</RefreshContext.Provider>
}

export const useRefresh = () => {
  const context = useContext(RefreshContext)
  if (!context) throw new Error('useRefresh must be used within RefreshProvider')
  return context
}

export function useManualRefresh(callback: () => void) {
  const ref = useRef(callback)
  ref.current = callback
  useEffect(() => {
    const sub = EventBus.addListener(REFRESH_EVENT, () => ref.current())
    return () => sub.remove()
  }, [])
}

// Refetch on 2nd+ visit to the current route (mirrors useMarkDataFetchers:
// skip first focus, refetch on subsequent focuses).
export function useMarkDataFetchers(callback: () => void) {
  const location = useLocation()
  const ref = useRef(callback)
  ref.current = callback
  const visitsRef = useRef<Record<string, number>>({})
  useEffect(() => {
    const key = location.pathname + location.searchStr
    const count = visitsRef.current[key] ?? 0
    visitsRef.current[key] = count + 1
    if (count >= 1) {
      ref.current()
    }
    // eslint-disable-next-line react-hooks/exhaustive-deps
  }, [location.pathname, location.searchStr])
}

// Run callback when the window regains focus (web analogue of screen focus).
export default function useFocusCallback(callback: () => void) {
  const ref = useRef(callback)
  ref.current = callback
  useEffect(() => {
    const onFocus = () => ref.current()
    window.addEventListener('focus', onFocus)
    return () => window.removeEventListener('focus', onFocus)
  }, [])
}