import {
  DatepickerFormatOptions, MonthsCalendarViewModel, CalendarCellViewModel
} from '../models/index';
import { startOf } from '../../bs-moment/utils/start-end-of';
import { shiftDate } from '../../bs-moment/utils/date-setters';
import { formatDate } from '../../bs-moment/format';
import { createMatrix } from '../utils/matrix-utils';

const height = 4;
const width = 3;
const shift = {month: 1};

export function formatMonthsCalendar(viewDate: Date, formatOptions: DatepickerFormatOptions): MonthsCalendarViewModel {
  const initialDate = startOf(viewDate, 'year');
  const matrixOptions = {width, height, initialDate, shift};
  const monthMatrix = createMatrix<CalendarCellViewModel>(matrixOptions,
    date => ({
      date,
      label: formatDate(date, formatOptions.monthLabel, formatOptions.locale)
    }));

  return {
    months: monthMatrix,
    monthTitle: '',
    yearTitle: formatDate(viewDate, formatOptions.yearTitle, formatOptions.locale)
  };
}