import {
  DEFAULT_SCHEDULE_START_TIME,
  DEFAULT_SCHEDULE_END_TIME,
  SCHEDULE_MINUTE_STEP,
} from '@mp-pilates/shared'

function buildHourOptions(): string[] {
  const startHour = parseInt(DEFAULT_SCHEDULE_START_TIME.slice(0, 2), 10)
  const endHour = parseInt(DEFAULT_SCHEDULE_END_TIME.slice(0, 2), 10)
  const list: string[] = []
  for (let h = startHour; h <= endHour; h++) {
    list.push(String(h).padStart(2, '0'))
  }
  return list
}

function buildMinuteOptions(): string[] {
  const list: string[] = []
  for (let m = 0; m < 60; m += SCHEDULE_MINUTE_STEP) {
    list.push(String(m).padStart(2, '0'))
  }
  return list
}

export const SCHEDULE_HOUR_OPTIONS = buildHourOptions()
export const SCHEDULE_MINUTE_OPTIONS = buildMinuteOptions()
export const SCHEDULE_TIME_PICKER_RANGE = [SCHEDULE_HOUR_OPTIONS, SCHEDULE_MINUTE_OPTIONS]

export function timeToMinutes(time: string): number {
  const [h, m] = time.split(':').map(Number)
  return h * 60 + (m || 0)
}

export function minutesToTime(total: number): string {
  const h = Math.floor(total / 60)
  const m = total % 60
  return `${String(h).padStart(2, '0')}:${String(m).padStart(2, '0')}`
}

export function timeToPickerIndex(time: string): number[] {
  let total = timeToMinutes(time || DEFAULT_SCHEDULE_START_TIME)
  const minTotal = timeToMinutes(DEFAULT_SCHEDULE_START_TIME)
  const maxTotal = timeToMinutes(DEFAULT_SCHEDULE_END_TIME)
  total = Math.max(minTotal, Math.min(maxTotal, total))
  total = Math.round(total / SCHEDULE_MINUTE_STEP) * SCHEDULE_MINUTE_STEP
  total = Math.max(minTotal, Math.min(maxTotal, total))

  const hour = String(Math.floor(total / 60)).padStart(2, '0')
  const minute = String(total % 60).padStart(2, '0')
  return [
    Math.max(0, SCHEDULE_HOUR_OPTIONS.indexOf(hour)),
    Math.max(0, SCHEDULE_MINUTE_OPTIONS.indexOf(minute)),
  ]
}

export function pickerIndexToTime(value: number[]): string {
  const hour = SCHEDULE_HOUR_OPTIONS[value[0]] ?? SCHEDULE_HOUR_OPTIONS[0]
  const minute = SCHEDULE_MINUTE_OPTIONS[value[1]] ?? SCHEDULE_MINUTE_OPTIONS[0]
  return `${hour}:${minute}`
}

/** 将 "HH:mm" 加一小时，不超过当日最晚结束时间 21:30 */
export function addOneHourCapped(time: string): string {
  const next = timeToMinutes(time) + 60
  const cap = timeToMinutes(DEFAULT_SCHEDULE_END_TIME)
  return minutesToTime(Math.min(next, cap))
}