import { dt } from "@/lib/dt"

import type { UseFormReturn } from "react-hook-form"
import type { IntlShape } from "react-intl"

import type { FormValues } from "@/types/components/hotelReservation/myStay/cancelStay"
import type { BookingConfirmation } from "@/types/trpc/routers/booking/confirmation"

export function getDefaultRooms(booking: BookingConfirmation["booking"]) {
  const { multiRoom, confirmationNumber, linkedReservations = [] } = booking

  if (!multiRoom) {
    return [{ id: "1", checked: true, confirmationNumber }]
  }

  const mainRoom = { id: "1", checked: false, confirmationNumber }
  const linkedRooms = linkedReservations.map((reservation, index) => ({
    id: `${index + 2}`,
    checked: false,
    confirmationNumber: reservation.confirmationNumber,
  }))

  return [mainRoom, ...linkedRooms]
}

export function formatStayDetails({
  booking,
  lang,
  intl,
}: {
  booking: BookingConfirmation["booking"]
  lang: string
  intl: IntlShape
}) {
  const { multiRoom } = booking
  const totalAdults = multiRoom
    ? (booking.adults ?? 0) +
      (booking.linkedReservations ?? []).reduce((acc, reservation) => {
        return acc + (reservation.adults ?? 0)
      }, 0)
    : (booking.adults ?? 0)
  const totalChildren = multiRoom
    ? booking.childrenAges?.length +
      (booking.linkedReservations ?? []).reduce((acc, reservation) => {
        return acc + reservation.children
      }, 0)
    : booking.childrenAges?.length

  const checkInDate = dt(booking.checkInDate)
    .locale(lang)
    .format("dddd D MMM YYYY")
  const checkOutDate = dt(booking.checkOutDate)
    .locale(lang)
    .format("dddd D MMM YYYY")
  const diff = dt(checkOutDate).diff(checkInDate, "days")

  const nightsText = intl.formatMessage(
    { id: "{totalNights, plural, one {# night} other {# nights}}" },
    { totalNights: diff }
  )
  const adultsText = intl.formatMessage(
    { id: "{totalAdults, plural, one {# adult} other {# adults}}" },
    { totalAdults: totalAdults }
  )
  const childrenText = intl.formatMessage(
    { id: "{totalChildren, plural, one {# child} other {# children}}" },
    { totalChildren: totalChildren }
  )

  return {
    checkInDate,
    checkOutDate,
    nightsText,
    adultsText,
    childrenText,
  }
}

function getMatchedRooms(
  booking: BookingConfirmation["booking"],
  checkedConfirmationNumbers: string[]
) {
  let matchedRooms = []

  // Main booking
  if (checkedConfirmationNumbers.includes(booking.confirmationNumber ?? "")) {
    matchedRooms.push({
      adults: booking.adults ?? 0,
      children: booking.childrenAges?.length ?? 0,
    })
  }

  // Linked reservations
  if (booking.linkedReservations) {
    const matchedLinkedRooms = booking.linkedReservations
      .filter((reservation) =>
        checkedConfirmationNumbers.includes(reservation.confirmationNumber)
      )
      .map((reservation) => ({
        adults: reservation.adults ?? 0,
        children: reservation.children ?? 0,
      }))

    matchedRooms = [...matchedRooms, ...matchedLinkedRooms]
  }

  return matchedRooms
}

function calculateTotals(matchedRooms: { adults: number; children: number }[]) {
  const totalAdults = matchedRooms.reduce((sum, room) => sum + room.adults, 0)
  const totalChildren = matchedRooms.reduce(
    (sum, room) => sum + room.children,
    0
  )
  return { totalAdults, totalChildren }
}

export const getCheckedRoomsCounts = (
  booking: BookingConfirmation["booking"],
  getValues: UseFormReturn<FormValues>["getValues"],
  intl: IntlShape
) => {
  const formRooms = getValues("rooms")
  const checkedFormRooms = formRooms.filter((room) => room.checked)
  const checkedConfirmationNumbers = checkedFormRooms
    .map((room) => room.confirmationNumber)
    .filter(
      (confirmationNumber): confirmationNumber is string =>
        confirmationNumber !== null && confirmationNumber !== undefined
    )

  const matchedRooms = getMatchedRooms(booking, checkedConfirmationNumbers)
  const { totalAdults, totalChildren } = calculateTotals(matchedRooms)

  const adultsText = intl.formatMessage(
    { id: "{totalAdults, plural, one {# adult} other {# adults}}" },
    { totalAdults: totalAdults }
  )
  const childrenText = intl.formatMessage(
    { id: "{totalChildren, plural, one {# child} other {# children}}" },
    { totalChildren: totalChildren }
  )

  return { adultsText, childrenText, totalChildren }
}