import type { Ref } from 'vue'
import type { Absence } from '~/services/dto/absence'
import type { EmployeeLeaveSummary } from '~/services/dto/employee-leave-summary'
import type { Employee } from '~/services/dto/employee'
import { CONTRACT_TYPES } from '~/services/dto/contract'
import { listAbsences } from '~/services/absences'
import { getEmployeeLeaveSummary, updateFractionedDays } from '~/services/employee-leave-summary'
import { listPublicHolidays } from '~/services/public-holidays'

export const useEmployeeLeave = (employee: Ref<Employee | null>, reloadEmployee: () => Promise<void>) => {
  const employeeAbsences = ref<Absence[]>([])
  const leaveSummary = ref<EmployeeLeaveSummary | null>(null)
  const publicHolidays = ref<Record<string, string>>({})
  const isLeaveLoading = ref(false)
  const leaveDataLoaded = ref(false)

  const getLeaveYear = () => {
    const now = new Date()
    const isForfait = employee.value?.contract?.type === CONTRACT_TYPES.FORFAIT
    return isForfait
      ? now.getFullYear()
      : (now.getMonth() >= 5 ? now.getFullYear() + 1 : now.getFullYear())
  }

  const loadLeaveData = async () => {
    if (!employee.value || isLeaveLoading.value) return
    isLeaveLoading.value = true
    try {
      const isForfait = employee.value.contract?.type === CONTRACT_TYPES.FORFAIT
      const leaveYear = getLeaveYear()
      const from = isForfait ? `${leaveYear}-01-01` : `${leaveYear - 1}-06-01`
      const to = isForfait ? `${leaveYear}-12-31` : `${leaveYear}-05-31`
      const holidayYears = isForfait ? [leaveYear] : [leaveYear - 1, leaveYear]

      const [absences, summary, ...holidayResults] = await Promise.all([
        listAbsences({ from, to, employeeId: employee.value.id }),
        getEmployeeLeaveSummary(employee.value.id, leaveYear),
        ...holidayYears.map((y) => listPublicHolidays('metropole', y))
      ])
      employeeAbsences.value = absences
      leaveSummary.value = summary
      publicHolidays.value = Object.assign({}, ...holidayResults)
      leaveDataLoaded.value = true
    } finally {
      isLeaveLoading.value = false
    }
  }

  const resetLoaded = () => {
    leaveDataLoaded.value = false
  }

  const submitFractionedDays = async (days: number) => {
    if (!employee.value) return
    const year = leaveSummary.value?.year ?? undefined
    await updateFractionedDays(employee.value.id, days, year)
    await reloadEmployee()
  }

  return {
    employeeAbsences,
    leaveSummary,
    publicHolidays,
    isLeaveLoading,
    leaveDataLoaded,
    loadLeaveData,
    resetLoaded,
    submitFractionedDays
  }
}