LR22 AKT

class Date {
    static const string fileBD;
    static string getNameMonth(int month) {
        if (month < 1)
            throw "A month cannot be less than 1";

        if (month > 12)
            throw "A month cannot be more than 12";

        string m[12] = {"january","february", "march", "april", "may", "june", "july", "august", "september", "october", "november", "december"};
        return m[month - 1];
    }
    int year, month, day;
    int maxDayInMonth(int month) {
        switch (month)
        {
            case 1:
            case 3:
            case 5:
            case 7:
            case 8:
            case 10:
            case 12:
                return 31;
            break;

            case 4:
            case 6:
            case 9:
            case 11:
                return 30;
            break;

            case 2:
                if (year % 4 == 0)
                    return 29;
                else
                    return 28;
            break;
        }
        return 0;
    }
public:
    Date() {
        day = 1;
        month = 1;
        year = 1900;
    }
    void setDay(int i) {
        if (i < 1)
            throw "Day cannot be less than 1";

        if (maxDayInMonth(month) < i)
            throw "A day cannot be more than this month";

        day = i;
    }

    void setMonth(int i ) {
        if (i < 1)
            throw "A month cannot be less than 1";

        if (i > 12)
            throw "A month cannot be more than 12";

        month = i;
        if (day > maxDayInMonth(i))
            setDay(maxDayInMonth(i));
    }

    void setYear(int i) {
        if (i < 1900)
            throw "A year cannot be less than 1900";

        year = i;
    }

    void addInBD() {
        ofstream bd(fileBD, ios::app);

        bd << day << " " << month << " " << year << endl;

        bd.close();
    }

    void print() { print(false);  }
    void print(bool a) {
        if (a) {
            cout << day << " " << getNameMonth(month) << " " << year << endl;
        } else {
            if (day < 10) cout << "0";
            cout << day << ".";

            if (month < 10) cout << "0";
            cout << month << "." << year << endl;
        }
    }

    static void printAllDates() {
        ifstream bd(fileBD);
        Date a; int i, l = 0;
        while (bd >> i) {
            a.setDay(i);
            bd >> i; a.setMonth(i);
            bd >> i; a.setYear(i);

            a.print();
            l++;
        }

        if (l == 0)
            cout << "The database is empty" << endl;
    }

    static void printAllSpringDates() {
        ifstream bd(fileBD);
        Date a; int i, n, l = 0;
        while (bd >> i) {
            a.setDay(i);
            bd >> n; a.setMonth(n);
            bd >> i; a.setYear(i);

            if (n >= 3 && n <= 5) {
                a.print();
                l++;
            }
        }
        if (l == 0)
            cout << "There are no spring dates" << endl;
    }

    static void printAllDatesWithStartLetter(char s) {
        ifstream bd(fileBD);
        Date a; int i, n, l = 0;
        while (bd >> i) {
            a.setDay(i);
            bd >> n; a.setMonth(n);
            bd >> i; a.setYear(i);

            if (getNameMonth(n)[0] == s) {
                a.print(true);
                l++;
            }
        }

        if (l == 0)
            cout << "No dates starting with letter " << s << endl;
    }
};

const string Date::fileBD = "bd.txt";

void addNewDate();
void showAllDates();
void showAllSpringDates();
void showAllDatesWithStartLetter();

int main()
{
    system("cls");
    int m;
    cout << "Menu:" << endl
         << "1 - Add new date" << endl
         << "2 - Show all dates" << endl
         << "3 - Show all spring dates" << endl
         << "4 - Show all dates whose month begins with the specified letter" << endl
         << "0/5 - Exit" << endl;

    cin >> m;
    switch (m)
    {
        case 1: addNewDate(); break;
        case 2: showAllDates(); break;
        case 3: showAllSpringDates(); break;
        case 4: showAllDatesWithStartLetter(); break;
        case 0: case 5: system("cls"); break;
        default: main(); break;
    }
}

void addNewDate() {
    int i;
    Date a;

    system("cls");
    cout << "Add new date" << endl
         << "0 - Exit in menu" << endl
         << "Enter day: ";

    try {
        cin >> i;
        if (i == 0) return (void)main();
        a.setDay(i);

        cout << "Enter the month number: ";
        cin >> i;
        if (i == 0) return (void)main();
        a.setMonth(i);

        cout << "Enter year: ";
        cin >> i;
        if (i == 0) return (void)main();
        a.setYear(i);
    } catch (const char* e) {
        cerr << e << endl;
        system("pause");
        return addNewDate();
    }

    a.addInBD();
    cout << "Date added to database" << endl;
    system("pause");
    addNewDate();
}

void showAllDates() {
    system("cls");
    cout << "Show all dates" << endl;
    Date::printAllDates();
    system("pause");
    main();
}

void showAllSpringDates() {
    system("cls");
    cout << "Show all spring dates" << endl;
    Date::printAllSpringDates();
    system("pause");
    main();
}

void showAllDatesWithStartLetter() {
    char a;

    system("cls");
    cout << "Show all dates whose month begins with the specified letter" << endl
         << "0 - Exit in Menu" << endl
         << "Enter a letter: ";

    cin >> a;
    if (a == '0') return (void)main();

    Date::printAllDatesWithStartLetter(a);
    system("pause");
    showAllDatesWithStartLetter();
}