import type {
  CategorizedFilters,
  Filter,
} from "../../../types/destinationFilterAndSort"
import type { DestinationPagesHotelData } from "../../../types/hotel"

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

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

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

  const filters = hotels.flatMap(({ hotel }) => hotel.detailedFacilities)
  const uniqueFilterNames = [...new Set(filters.map((filter) => filter.name))]
  const filterList = uniqueFilterNames
    .map((filterName) => {
      const filter = filters.find((filter) => filter.name === filterName)
      return filter
        ? {
            name: filter.name,
            slug: filter.slug,
            filterType: filter.filter,
            sortOrder: filter.sortOrder,
          }
        : null
    })
    .filter((filter): filter is Filter => !!filter)

  const facilityFilters = filterList.filter((filter) =>
    HOTEL_FACILITIES_FILTER_TYPE_NAMES.includes(filter.filterType)
  )
  const surroundingsFilters = filterList.filter((filter) =>
    HOTEL_SURROUNDINGS_FILTER_TYPE_NAMES.includes(filter.filterType)
  )
  return {
    facilityFilters: sortFilters(facilityFilters),
    surroundingsFilters: sortFilters(surroundingsFilters),
  }
}

function sortFilters(filters: Filter[]): Filter[] {
  return [...filters].sort((a, b) => {
    // First sort by sortOrder
    const orderDiff = a.sortOrder - b.sortOrder
    // If sortOrder is the same, sort by name as secondary criterion
    return orderDiff === 0 ? a.name.localeCompare(b.name) : orderDiff
  })
}