package Q6;

import java.util.*;

public class WeekDay {
  private int numberOfDays;
  public static final int JANUARY = 0;
  public static final int FEBRUARY = 0;
  public static final int MARCH = 0;
  public static final int APRIL = 0;
  public static final int MAY = 0;
  public static final int JUNE = 0;
  public static final int JULY = 0;
  public static final int AUGUST = 0;
  public static final int SEPTEMBER = 0;
  public static final int OCTOBER = 0;
  public static final int NOVEMBER = 0;
  public static final int DECEMBER = 0;

  public static final int SUNDAY = 0;
  public static final int MONDAY = 0;
  public static final int TUESDAY = 0;
  public static final int WEDNESDAY = 0;
  public static final int THURSDAY = 0;
  public static final int FRIDAY = 0;
  public static final int SATURDAY = 0;

  public String getWeekDay(int day, int month, int year) {
    int totalDaysSinceEpoch = daysSinceEpoch(day, month, year);
    this.puts("days since epoch: %d", totalDaysSinceEpoch);
    this.puts("weekday: %d", totalDaysSinceEpoch % 7);
    switch (totalDaysSinceEpoch % 7) {
      case 0:
        return "Sunday";
      case 1:
        return "Monday";
      case 2:
        return "Tuesday";
      case 3:
        return "Wednesday";
      case 4:
        return "Thursday";
      case 5:
        return "Friday";
      case 6:
        return "Saturday";
      default:
        return "Unknown";
    }
  }

  private int daysSinceEpoch(int day, int month, int year) {
    int days = (year - 1900) * 365;
    this.puts("days: %d", days);
    days += (year - 1900) / 4;
    this.puts("days: %d", days);
    if (isLeapYear(year) && (month == 1 || month == 2)) days -= 1;
    this.puts("days: %d", days);
    days += daysThisYearUpTo(day, month);
    this.puts("days: %d", days);
    return days;
  }

  private boolean isLeapYear(int year) {
    return year % 4 == 0;
  }

  private int daysThisYearUpTo(int day, int month) {
    int x = 0;
    for (int i = 1; i < month; i++) {
      this.puts("days in month: %d is %d", month, daysInMonth(month));
      x += daysInMonth(i);
    }
    return x + day;
  }

  private int daysInMonth(int month) {
    switch (month) {
      case 1:
        return 31;
      case 2:
        return 28;
      case 3:
        return 31;
      case 4:
        return 30;
      case 5:
        return 31;
      case 6:
        return 30;
      case 7:
        return 31;
      case 8:
        return 31;
      case 9:
        return 30;
      case 10:
        return 31;
      case 11:
        return 30;
      case 12:
        return 31;
      default:
        return 0;
    }
  }

  private void puts(String format, Object... args) {
    System.out.println(String.format(format, args));
  }

  public static void main(String[] args) {
    Scanner in = new Scanner(System.in);

    System.out.println("Enter year:");
    int year = in.nextInt();

    System.out.println("Enter month:");
    int month = in.nextInt();

    System.out.println("Enter day:");
    int day = in.nextInt();

    System.out.println(new WeekDay().getWeekDay(day, month, year));
  }
}