#include "types.h"
#include <stdio.h>

bool is_leap_year(int year) {
  return (year % 4 == 0 && year % 100 != 0) ||
         (year % 4 == 0 && year % 400 == 0);
}

/**
 * Determine whether the provided date is valid.
 *
 * @param date Datová struktura reprezentující datum
 *
 * @return `true` v případě validního data, `false` jinak
 */
bool is_valid_date(struct date_t date) {
  return !(date.day > 31 || date.day < 1 || date.month > 12 || date.month < 1 ||
           (date.month == 2 && date.day > 29 && is_leap_year(date.year)) ||
           (date.month == 2 && date.day > 28 && !is_leap_year(date.year)) ||
           date.year < 1582 || date.year > 2024 ||
           ((date.month == 4 || date.month == 6 || date.month == 9 ||
             date.month == 11) &&
            date.day > 30));
}

/**
 * Find the earlier date by comparing years, months and days.
 *
 * @param date1 Datová struktura reprezentující první datum
 * @param date2 Datová struktura reprezentující druhé datum
 *
 * @return `DATE1_IS_EARLIER` v případě date1 je dřívější,
 *     `DATE1_IS_LATER` když date2 je dřívější,
 *     `DATES_ARE_EQUAL` jinak (data jsou stejná)
 */
int earlier_date(struct date_t date1, struct date_t date2) {
  // TODO: implementujte funkci dle zadání
  if (date1.year == date2.year && date1.month == date2.month &&
      date1.day == date2.day) {
    return DATES_ARE_EQUAL;
  }

  if (date1.year < date2.year ||
      (date1.year == date2.year && date1.month < date2.month) ||
      (date1.year == date2.year && date1.month == date2.month &&
       date1.day < date2.day)) {
    return DATE1_IS_EARLIER;
  }

  return DATE1_IS_LATER;
}

#ifndef TEST_BUILD

int main(void) {
  struct date_t date1, date2;

  // Load two dates from the user
  printf("Provide the first date (format yyyy-mm-dd): ");
  scanf("%d-%d-%d", &date1.year, &date1.month, &date1.day);

  printf("Provide the second date (format yyyy-mm-dd): ");
  scanf("%d-%d-%d", &date2.year, &date2.month, &date2.day);

  // Check that the dates are valid
  if (!is_valid_date(date1) || !is_valid_date(date2)) {
    printf("Invalid date!\n");
    return 1;
  }

  // Compare the dates and find the earlier one
  int earlier = earlier_date(date1, date2);
  if (earlier == DATE1_IS_EARLIER) {
    printf("The date %d-%d-%d is earlier.\n", date1.year, date1.month,
           date1.day);
  } else if (earlier == DATE1_IS_LATER) {
    printf("The date %d-%d-%d is earlier.\n", date2.year, date2.month,
           date2.day);
  } else {
    printf("The dates are the same.\n");
  }

  return 0;
}

#endif