import { useState, useEffect, useCallback } from 'react'
import * as api from '@/services/api'
import type { PlannedLeaveDay } from '@/types'

interface UsePlannedDaysResult {
  data: PlannedLeaveDay[] | null
  isLoading: boolean
  error: string | null
  refresh: () => Promise<void>
  add: (payload: api.CreatePlannedDayPayload) => Promise<PlannedLeaveDay>
  update: (id: string, payload: api.UpdatePlannedDayPayload) => Promise<PlannedLeaveDay>
  remove: (id: string) => Promise<void>
}

export function usePlannedDays(childId?: string): UsePlannedDaysResult {
  const [data, setData] = useState<PlannedLeaveDay[] | null>(null)
  const [isLoading, setIsLoading] = useState(false)
  const [error, setError] = useState<string | null>(null)

  const fetch = useCallback(async () => {
    if (!childId) {
      // The child this data belongs to is gone (e.g. a logout cleared the
      // selection) — clear rather than leave the previous account's
      // planned days rendered until a new childId arrives.
      setData(null)
      setError(null)
      return
    }
    setIsLoading(true)
    setError(null)
    try {
      const response = await api.getPlannedDays(childId)
      setData(response)
    } catch (err) {
      setError(err instanceof Error ? err.message : 'Failed to fetch planned days')
      setData(null)
    } finally {
      setIsLoading(false)
    }
  }, [childId])

  const add = useCallback(
    async (payload: api.CreatePlannedDayPayload) => {
      const result = await api.createPlannedDay(payload)
      await fetch()
      return result
    },
    [fetch],
  )

  const update = useCallback(
    async (id: string, payload: api.UpdatePlannedDayPayload) => {
      const result = await api.updatePlannedDay(id, payload)
      await fetch()
      return result
    },
    [fetch],
  )

  const remove = useCallback(
    async (id: string) => {
      await api.deletePlannedDay(id)
      await fetch()
    },
    [fetch],
  )

  useEffect(() => {
    fetch()
  }, [fetch])

  return { data, isLoading, error, refresh: fetch, add, update, remove }
}