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

import type { IntlShape } from "react-intl"

/**
 * Returns relative past time text for a date (e.g., "3 days ago", "2 months ago", "1 year ago")
 *
 * Examples:
 * - 1-30 days: "1 day ago", "15 days ago", "30 days ago"
 * - 31-364 days: "1 month ago", "6 months ago", "12 months ago"
 * - 365+ days: "1 year ago", "2 years ago", "5 years ago"
 * - Returns empty string for future dates.
 *
 */
export function getTimeAgoText(checkoutDate: string, intl: IntlShape): string {
  const now = dt()
  const checkout = dt(checkoutDate)
  const daysDiff = now.diff(checkout, "days")

  // Return empty string for future dates
  if (daysDiff < 0) {
    return ""
  }

  if (daysDiff <= 30) {
    // 1-30 days
    return intl.formatMessage(
      {
        id: "common.nrDaysAgo",
        defaultMessage: "{count, plural, one {# day ago} other {# days ago}}",
      },
      { count: daysDiff }
    )
  }

  if (daysDiff <= 364) {
    // 31-364 days (show months)
    const monthsDiff = Math.floor(daysDiff / 30)
    return intl.formatMessage(
      {
        id: "common.nrMonthsAgo",
        defaultMessage:
          "{count, plural, one {# month ago} other {# months ago}}",
      },
      { count: monthsDiff }
    )
  }

  // 365+ days (show years)
  const yearsDiff = Math.floor(daysDiff / 365)
  return intl.formatMessage(
    {
      id: "common.nrYearsAgo",
      defaultMessage: "{count, plural, one {# year ago} other {# years ago}}",
    },
    { count: yearsDiff }
  )
}