import { getHotel } from "@/lib/trpc/memoizedRequests"
import { serverClient } from "@/lib/trpc/server"

import { getLang } from "@/i18n/serverContext"

import type {
  AlternativeHotelsAvailabilityInput,
  AvailabilityInput,
} from "@/types/components/hotelReservation/selectHotel/availabilityInput"
import type {
  HotelData,
  NullableHotelData,
} from "@/types/components/hotelReservation/selectHotel/hotelCardListingProps"
import type {
  CategorizedFilters,
  Filter,
} from "@/types/components/hotelReservation/selectHotel/hotelFilters"
import type { HotelsAvailabilityItem } from "@/types/trpc/routers/hotel/availability"

const hotelSurroundingsFilterNames = [
  "Hotel surroundings",
  "Hotel omgivelser",
  "Hotelumgebung",
  "Hotellia lähellä",
  "Hotellomgivelser",
  "Omgivningar",
]

const hotelFacilitiesFilterNames = [
  "Hotel facilities",
  "Hotellfaciliteter",
  "Hotelfaciliteter",
  "Hotel faciliteter",
  "Hotel-Infos",
  "Hotellin palvelut",
]

export async function fetchAvailableHotels(
  input: AvailabilityInput
): Promise<NullableHotelData[]> {
  const availableHotels =
    await serverClient().hotel.availability.hotelsByCity(input)

  if (!availableHotels) return []

  return enhanceHotels(availableHotels)
}

export async function fetchBookingCodeAvailableHotels(
  input: AvailabilityInput
): Promise<NullableHotelData[]> {
  const availableHotels =
    await serverClient().hotel.availability.hotelsByCityWithBookingCode(input)

  if (!availableHotels) return []

  return enhanceHotels(availableHotels)
}

export async function fetchAlternativeHotels(
  hotelId: string,
  input: AlternativeHotelsAvailabilityInput
): Promise<NullableHotelData[]> {
  const alternativeHotelIds = await serverClient().hotel.nearbyHotelIds({
    hotelId,
  })

  if (!alternativeHotelIds) return []

  const availableHotels =
    await serverClient().hotel.availability.hotelsByHotelIds({
      ...input,
      hotelIds: alternativeHotelIds,
    })

  if (!availableHotels) return []

  return enhanceHotels(availableHotels)
}

async function enhanceHotels(hotels: {
  availability: HotelsAvailabilityItem[]
}) {
  const language = getLang()

  const hotelFetchers = hotels.availability.map(async (hotel) => {
    const hotelData = await getHotel({
      hotelId: hotel.hotelId.toString(),
      isCardOnlyPayment: false,
      language,
    })

    if (!hotelData) return { hotelData: null, price: hotel.productType }

    return {
      hotelData: hotelData.hotel,
      price: hotel.productType,
    }
  })

  return await Promise.all(hotelFetchers)
}

export function getFiltersFromHotels(hotels: HotelData[]): CategorizedFilters {
  if (hotels.length === 0)
    return { facilityFilters: [], surroundingsFilters: [] }

  const filters = hotels.flatMap((hotel) => {
    if (!hotel.hotelData) return []
    return hotel.hotelData.detailedFacilities
  })

  const uniqueFilterIds = [...new Set(filters.map((filter) => filter.id))]
  const filterList: Filter[] = uniqueFilterIds
    .map((filterId) => filters.find((filter) => filter.id === filterId))
    .filter((filter): filter is Filter => filter !== undefined)
    .sort((a, b) => b.sortOrder - a.sortOrder)

  return filterList.reduce<CategorizedFilters>(
    (acc, filter) => {
      if (filter.filter && hotelSurroundingsFilterNames.includes(filter.filter))
        return {
          facilityFilters: acc.facilityFilters,
          surroundingsFilters: [...acc.surroundingsFilters, filter],
        }

      if (filter.filter && hotelFacilitiesFilterNames.includes(filter.filter))
        return {
          facilityFilters: [...acc.facilityFilters, filter],
          surroundingsFilters: acc.surroundingsFilters,
        }

      return acc
    },
    { facilityFilters: [], surroundingsFilters: [] }
  )
}