import type { DateRange } from './types';

export const startOfLocalDay = (date: Date): Date => {
  const nextDate = new Date(date);
  nextDate.setHours(0, 0, 0, 0);
  return nextDate;
};

export const endOfLocalDay = (date: Date): Date => {
  const nextDate = new Date(date);
  nextDate.setHours(23, 59, 59, 999);
  return nextDate;
};

export const rangeForDay = (date: Date): DateRange => ({
  start: startOfLocalDay(date),
  end: endOfLocalDay(date),
});

export const rangeForLastDays = (days: number, today = new Date()): DateRange => {
  const end = endOfLocalDay(today);
  const start = startOfLocalDay(today);
  start.setDate(start.getDate() - Math.max(days - 1, 0));
  return { start, end };
};

export const rangeForPreviousDay = (today = new Date()): DateRange => {
  const date = startOfLocalDay(today);
  date.setDate(date.getDate() - 1);
  return rangeForDay(date);
};

export const parseLocalDateInput = (value: string): Date | null => {
  if (!value) return null;

  const match = value.match(/^(\d{4})-(\d{2})-(\d{2})$/);
  if (!match) return null;

  const [, yearValue, monthValue, dayValue] = match;
  const date = new Date(Number(yearValue), Number(monthValue) - 1, Number(dayValue));

  if (
    date.getFullYear() !== Number(yearValue) ||
    date.getMonth() !== Number(monthValue) - 1 ||
    date.getDate() !== Number(dayValue)
  ) {
    return null;
  }

  return date;
};

export const formatDateParam = (date: Date): string => {
  const year = date.getFullYear();
  const month = String(date.getMonth() + 1).padStart(2, '0');
  const day = String(date.getDate()).padStart(2, '0');
  return `${year}-${month}-${day}`;
};