import { dt } from "@scandic-hotels/common/dt"
import { getReedemableCoupons } from "@scandic-hotels/trpc/routers/contentstack/reward/helpers"
import {
  RESTAURANT_REWARD_IDS,
  type RestaurantRewardId,
  REWARD_IDS,
  type RewardId,
} from "@scandic-hotels/trpc/types/rewards"

import type {
  ApiReward,
  RedeemableCoupon,
  RedeemLocation,
} from "@scandic-hotels/trpc/types/reward"
import type { Dayjs } from "dayjs"

export {
  getEarliestExpirationDate,
  getFirstRedeemableCoupon,
  isRestaurantOnSiteTierReward,
  isValidRewardId,
}

function isValidRewardId(id: string): id is RewardId {
  return Object.values<string>(REWARD_IDS).includes(id)
}

function isRestaurantReward(rewardId: string): rewardId is RestaurantRewardId {
  return RESTAURANT_REWARD_IDS.some((id) => id === rewardId)
}

function redeemLocationIsOnSite(
  location: RedeemLocation
): location is "On-site" {
  return location === "On-site"
}

export function isTierType(type: string): type is "Tier" {
  return type === "Tier"
}

function isOnSiteTierReward(reward: ApiReward): boolean {
  return (
    redeemLocationIsOnSite(reward.redeemLocation) &&
    isTierType(reward.rewardType)
  )
}

function isRestaurantOnSiteTierReward(reward: ApiReward): boolean {
  return isOnSiteTierReward(reward) && isRestaurantReward(reward.rewardId)
}

function getFirstRedeemableCoupon(reward: ApiReward): RedeemableCoupon {
  const sortedCoupons = getReedemableCoupons(reward).sort((a, b) => {
    // null values used instead of undefined, otherwise it will return current time
    return dt(a.expiresAt ?? null).valueOf() - dt(b.expiresAt ?? null).valueOf()
  })
  return sortedCoupons[0]
}

function getEarliestExpirationDate(reward: ApiReward) {
  return getReedemableCoupons(reward)
    .map(({ expiresAt }) => expiresAt)
    .filter((expiresAt): expiresAt is string => !!expiresAt)
    .reduce((earliestDate: Dayjs | null, expiresAt) => {
      const expiresAtDate = dt(expiresAt)
      if (!earliestDate) {
        return expiresAtDate
      }

      return earliestDate.isBefore(expiresAtDate) ? earliestDate : expiresAtDate
    }, null)
}