import { isSameYear, shiftDate } from 'ngx-bootstrap/chronos';
import { YearsCalendarViewModel, CalendarCellViewModel } from '../models';
import { isDisabledDate, isEnabledDate, isYearDisabled } from '../utils/bs-calendar-utils';

export interface FlagYearsCalendarOptions {
  isDisabled: boolean;
  minDate: Date;
  maxDate: Date;
  hoveredYear: Date;
  selectedDate: Date;
  selectedRange: Date[];
  datesDisabled: Date[];
  datesEnabled: Date[];
  displayMonths: number;
  yearIndex: number;
}

export function flagYearsCalendar(
  yearsCalendar: YearsCalendarViewModel,
  options: Partial<FlagYearsCalendarOptions>
): YearsCalendarViewModel {
  yearsCalendar.years.forEach(
    (years: CalendarCellViewModel[], rowIndex: number) => {
      years.forEach((year: CalendarCellViewModel, yearIndex: number) => {
        let isSelected: boolean;
        const isHovered = isSameYear(year.date, options.hoveredYear);
        const isDisabled =
          options.isDisabled ||
          isDisabledDate(year.date, options.datesDisabled, 'year') ||
          isEnabledDate(year.date, options.datesEnabled, 'year') ||
          isYearDisabled(year.date, options.minDate, options.maxDate);

        if (!options.selectedDate && options.selectedRange) {
          isSelected = isSameYear(year.date, options.selectedRange[0]);
          if (!isSelected) {
            isSelected = isSameYear(year.date, options.selectedRange[1]);
          }
        } else {
          isSelected = isSameYear(year.date, options.selectedDate);
        }

        const newMonth = Object.assign(/*{},*/ year, { isHovered, isDisabled, isSelected });
        if (
          year.isHovered !== newMonth.isHovered ||
          year.isDisabled !== newMonth.isDisabled ||
          year.isSelected !== newMonth.isSelected
        ) {
          yearsCalendar.years[rowIndex][yearIndex] = newMonth;
        }
      });
    }
  );

  // todo: add check for linked calendars
  yearsCalendar.hideLeftArrow =
    !!options.yearIndex && options.yearIndex > 0 && options.yearIndex !== options.displayMonths;
  yearsCalendar.hideRightArrow =
    !!options.yearIndex && !!options.displayMonths &&
    options.yearIndex < options.displayMonths &&
    options.yearIndex + 1 !== options.displayMonths;

  yearsCalendar.disableLeftArrow = isYearDisabled(
    shiftDate(yearsCalendar.years[0][0].date, { year: -1 }),
    options.minDate,
    options.maxDate
  );
  const i = yearsCalendar.years.length - 1;
  const j = yearsCalendar.years[i].length - 1;
  yearsCalendar.disableRightArrow = isYearDisabled(
    shiftDate(yearsCalendar.years[i][j].date, { year: 1 }),
    options.minDate,
    options.maxDate
  );

  return yearsCalendar;
}