import {
  ColumnType,
  DateFormat,
  ITypeOptions,
  Language,
  TimeFormat,
} from '../../../types';
import { exhaustiveSwitch } from '../../../typeUtils';

import format from 'date-fns/format';
import parseISO from 'date-fns/parseISO';

export const transformDatetimeToString = (
  value: string | number,
  typeOptions: Pick<
    ITypeOptions<ColumnType.DATETIME>,
    'includeTime' | 'timeFormat' | 'dateFormat'
  >,
  locale?: Language
) => {
  if (!value) return '';

  const dateFormatString = (() => {
    switch (typeOptions.dateFormat) {
      case DateFormat.FRIENDLY:
        if (locale === Language.en) {
          return 'MMM do, yyyy';
        } else {
          return 'yyyy年M月d日';
        }
      case DateFormat.ISO:
        return 'yyyy-MM-dd';
      case DateFormat.SLASH:
        return 'yyyy/MM/dd';
      case DateFormat.LOCAL:
      case DateFormat.FORMULA_PARSE_FORMAT:
        return 'MM/dd/yyyy';
      default: {
        return exhaustiveSwitch({
          switchValue: typeOptions.dateFormat,
          returnValue: 'MM/dd/yyyy',
        });
      }
    }
  })();

  // Date time value may be a date string or a timestamp
  const parsedValue = typeof value === 'number' ? value : parseISO(value);

  const datePart = format(parsedValue, dateFormatString);

  if (!typeOptions.includeTime) return datePart;

  const timePart = format(
    parsedValue,
    typeOptions.timeFormat === TimeFormat.TWELVE_HOUR ? 'h:mm aaa' : 'HH:mm'
  );

  return `${datePart} ${timePart}`;
};