package fr.istic.vv;

class Date implements Comparable<Date> {
    private int day;
    private int month;
    private int year;

    public Date(int day, int month, int year) {
        if (isValidDate(day, month, year)) {
            this.day = day;
            this.month = month;
            this.year = year;
        } else {
            throw new IllegalArgumentException("Invalid date");
        }
    }

    public static boolean isValidDate(int day, int month, int year) {
        if (month < 1 || month > 12 || day < 1 || day > 31)
            return false;
        int max_day = max_day(month, year);
        if (day > max_day)
            return false;
        return true;
    }

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

    public Date nextDate() {
        int d = this.getDay();
        int m = this.getMonth();
        int y = this.getYear();
        int max_day = max_day(m, y);
        if (d < max_day) {
            return new Date(d + 1, m, y);
        } else {
            if (m == 12) {
                return new Date(1, 1, y + 1);
            } else {
                return new Date(1, m + 1, y);
            }
        }
    }

    public Date previousDate() {
        int d = this.getDay();
        int m = this.getMonth();
        int y = this.getYear();
        if (d == 1) {
            if (m == 1) {
                return new Date(31, 12, y - 1);
            } else {
                return new Date(max_day(m - 1, y), m - 1, y);
            }
        } else {
            return new Date(d - 1, m, y);
        }
    }

    public int compareTo(Date other) {
        if (other == null) {
            throw new NullPointerException();
        }
        int cmpYear = Integer.compare(this.getYear(), other.getYear());
        if (cmpYear != 0)
            return cmpYear;

        int cmpMonth = Integer.compare(this.getMonth(), other.getMonth());
        if (cmpMonth != 0)
            return cmpMonth;

        return Integer.compare(this.getDay(), other.getDay());

    }

    public int getDay() {
        return day;
    }

    public int getMonth() {
        return month;
    }

    public int getYear() {
        return year;
    }

    private static int max_day(int month, int year) {
        int max_verstappen;
        switch (month) {
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                max_verstappen = 31;
                break;
            case 4:
            case 6:
            case 9:
            case 11:
                max_verstappen = 30;
                break;
            case 2: {
                if (isLeapYear(year)) {
                    max_verstappen = 29;
                    break;
                } else {
                    max_verstappen = 28;
                    break;
                }
            }
            default:
                max_verstappen = 0;
                break;
        }
        return max_verstappen;
    }
}