import { useMemo } from 'react'
import { WEEKDAYS } from '../constants.js'
import { parseTimeToMinutes } from '../utils/index.js'
// Ensure WEEKDAYS is defined in an external constants file
type Input = [string, string]

export type HumanReadableOpeningHours = {
  openDay  :string;
  closeDay :string;
  openTime :string;
  closeTime:string;
}

type Options = {
  format?:12 | 24;
}

/**
 * Converts opening and closing hours of the week into a human-readable format,
 * with an option to format times in 12-hour or 24-hour format.
 *
 * @param {Input} input -
 * Tuple representing opening and closing times in "hours:minutes" format.
 * @param {Options} options -
 * Configuration options, including time format.
 * @returns {HumanReadableOpeningHours} An object with human-readable
 * opening and closing days and times.
 */
const useHumanReadableOpeningHours = (
  input: Input,
  options?: Options,
): HumanReadableOpeningHours => useMemo(
  () => {
    // Destructure options in the function body with a default value for format
    const { format = 24 } = options || {}

    const days = Object.values(WEEKDAYS)

    const calculateDayAndTime = (totalMinutes: number) => {
      const dayIndex = Math.floor(totalMinutes / (24 * 60)) % 7
      const day = days[dayIndex]
      let hour = Math.floor((totalMinutes % (24 * 60)) / 60)
      const minute = (totalMinutes % (24 * 60)) % 60
      let suffix = ''
      if (format === 12) {
        suffix = hour >= 12 ? ' PM' : ' AM'
        hour = hour % 12 || 12 // Convert 0 to 12 for 12-hour format
      }
      const time = `${hour.toString().padStart(
        2, '0',
      )}:${minute
        .toString()
        .padStart(
          2, '0',
        )}${suffix}`
      return {
        day,
        time,
      }
    }

    const [
      openMinutes,
      closeMinutes,
    ] = input.map(parseTimeToMinutes)

    const openInfo = calculateDayAndTime(openMinutes)
    const closeInfo = calculateDayAndTime(closeMinutes)

    // Adjust closeDay if closing time is the next week
    const adjustedCloseDay = openMinutes <= closeMinutes
      ? closeInfo.day
      : days[(days.indexOf(closeInfo.day) + 1) % 7]

    return {
      openDay  :openInfo.day,
      closeDay :adjustedCloseDay,
      openTime :openInfo.time,
      closeTime:closeInfo.time,
    }
  }, [
    input,
    options,
  ],
)

export default useHumanReadableOpeningHours