import dayjs, { Dayjs } from 'dayjs';
import jalaliday from 'jalaliday';

dayjs.extend(jalaliday);

export interface MonthInfo {
  isCurrentMonth: boolean;
  firstDateOfMonth: dayjs.Dayjs;
  lastDateOfMonth: dayjs.Dayjs;
  monthDaysCount: number;
  firstDayOfMonth: number;
  jalaliFirstDayOfMonth: number;
  monthTitle: string;
  monthIndex: number;
  prevMonthIsDisabled: boolean;
  nextMonthIsDisabled: boolean;
  isDisabled: boolean;
}

export interface MonthlyWeekDate {
  gregorianDate: string;
  date: string;
  isNextMonth: boolean;
  isPastMonth: boolean;
  isCurrentDay: boolean;
  isPastDate: boolean;
  isFutureDate: boolean;
  dayText: string;
  day: number;
  isHoliday: boolean;
  isDisabled: boolean;
}

export const daysName = ['شنبه', 'یکشنبه', 'دوشنبه', 'سه شنبه', 'چهارشنبه', 'پنجشنبه', 'جمعه'];

export function prepareMonthInfo(activeDate: string | Date, min?: string, max?: string): MonthInfo {
  const date = dayjs(activeDate).calendar('jalali');

  const firstDayOfMonth = date.startOf('month').day();

  return {
    isCurrentMonth: dayjs().calendar('jalali').isSame(date, 'month'),

    firstDateOfMonth: date.startOf('month'),

    lastDateOfMonth: date.endOf('month'),

    monthDaysCount: date.daysInMonth(),

    firstDayOfMonth,

    jalaliFirstDayOfMonth: firstDayOfMonth === 6 ? 0 : firstDayOfMonth + 1,

    monthTitle: date.locale('fa').format('MMMM YYYY'),

    monthIndex: date.get('month'),

    isDisabled: false,
    nextMonthIsDisabled: false,
    prevMonthIsDisabled: false,
  };
}

export function prepareWeekDayDates(
  monthInfo: MonthInfo,
  min?: string,
  max?: string
): MonthlyWeekDate[][] {
  const weekDaysDates: MonthlyWeekDate[][] = [];

  const { monthDaysCount, firstDateOfMonth } = monthInfo;

  for (let i = 0; i < monthDaysCount; i++) {
    const date = firstDateOfMonth.add(i, 'day');

    const dateDay = date.day();

    const persianDateDay = dateDay === 6 ? 0 : dateDay + 1;

    if (i === 0 || persianDateDay === 0) {
      weekDaysDates.push(new Array(7) as MonthlyWeekDate[]);
    }

    if (i === 0) {
      for (let j = 0; j < persianDateDay; j++) {
        weekDaysDates[0][j] = weekDateFactory(
          date.add(-persianDateDay + j, 'day'),
          monthInfo,
          min,
          max
        );
      }
    }

    weekDaysDates[weekDaysDates.length - 1][persianDateDay] = weekDateFactory(
      date,
      monthInfo,
      min,
      max
    );

    if (i === monthDaysCount - 1) {
      for (let j = persianDateDay + 1; j < 7; j++) {
        weekDaysDates[weekDaysDates.length - 1][j] = weekDateFactory(
          date.add(j - persianDateDay, 'day'),
          monthInfo,
          min,
          max
        );
      }
    }
  }

  return weekDaysDates;
}

function weekDateFactory(
  date: dayjs.Dayjs,
  monthInfo: MonthInfo,
  min?: string,
  max?: string
): MonthlyWeekDate {
  const now = dayjs().calendar('jalali');

  const formattedDate = date.format('YYYY-MM-DD');

  return {
    gregorianDate: date.calendar('gregory').format('YYYY-MM-DD'),

    date: formattedDate,

    isNextMonth: date.month() > monthInfo.monthIndex,

    isPastMonth: date.month() < monthInfo.monthIndex,

    isCurrentDay: now.isSame(date, 'day'),

    isPastDate: date.isBefore(now, 'day'),

    isFutureDate: now.isBefore(date, 'day'),

    dayText: date.locale('fa').format('D MMMM'),

    day: Number(date.locale('fa').format('D')),

    isDisabled: isDisabledDate(date, min, max),

    // Replace with your own holiday service
    isHoliday: false,
  };
}

function isDisabledDate(date: Dayjs, min?: string, max?: string) {
  if (min && date.isBefore(dayjs(min), 'day')) {
    return true;
  }

  if (max && date.isAfter(dayjs(max), 'day')) {
    return true;
  }
  return false;
}