import { dt } from "@scandic-hotels/common/dt"

import type { Dayjs } from "dayjs"

/**
 * Get valid dates from stringFromDate and stringToDate making sure that they are not in the past and chronologically correct
 * @example const { fromDate, toDate} = getValidDates("2021-01-01", "2021-01-02")
 */
export function getValidDates(
  stringFromDate: string | undefined,
  stringToDate: string | undefined
): { fromDate: Dayjs; toDate: Dayjs } {
  const fromDate = getValidFromDate(stringFromDate)
  const toDate = getValidToDate(stringToDate, fromDate)

  return { fromDate, toDate }
}

/**
 * Get valid fromDate from stringFromDate making sure that it is not in the past
 */
export function getValidFromDate(stringFromDate: string | undefined): Dayjs {
  const now = dt().utc()
  if (!stringFromDate) {
    return now
  }
  const toDate = dt(stringFromDate)

  const yesterday = now.subtract(1, "day")
  if (!toDate.isAfter(yesterday)) {
    return now
  }

  return toDate
}

/**
 * Get valid toDate from stringToDate making sure that it is after fromDate
 */
export function getValidToDate(
  stringToDate: string | undefined,
  fromDate: Dayjs | Date
): Dayjs {
  const tomorrow = dt().utc().add(1, "day")
  if (!stringToDate) {
    return tomorrow
  }

  const toDate = dt(stringToDate)
  if (toDate.isAfter(fromDate)) {
    return toDate
  }

  return tomorrow
}