web/packages/trpc/lib/utils/getSortedCities.ts

import { SortOption } from "../enums/destinationFilterAndSort"

import type { DestinationCityListItem } from "../types/destinationCityPage"

const CITY_SORTING_STRATEGIES: Partial<
  Record<
    SortOption,
    (a: DestinationCityListItem, b: DestinationCityListItem) => number
  >
> = {
  [SortOption.Name]: function (a, b) {
    return a.cityName.localeCompare(b.cityName)
  },
  [SortOption.Recommended]: function (a, b) {
    if (a.sort_order === null && b.sort_order === null) {
      return a.cityName.localeCompare(b.cityName)
    }
    if (a.sort_order === null) {
      return 1
    }
    if (b.sort_order === null) {
      return -1
    }
    return b.sort_order - a.sort_order
  },
}

export function getSortedCities(
  cities: DestinationCityListItem[],
  sortOption: SortOption
) {
  const sortFn = CITY_SORTING_STRATEGIES[sortOption]
  return sortFn ? cities.sort(sortFn) : cities
}