date.cpp

#include "date.h"
#include <iostream>

using namespace std;

date::date() {
    init();
}

date::date(int y) {
    init();
    setYear(y);
}

date::date(int m, int y) {
    init();
    setMonth(m);
    setYear(y);
}

date::date(int d, int m, int y) {
    init();
    setYear(y);
    setMonth(m);
    setDay(d);
}

date::date(date const &d) {
    init();
    day = d.day;
    month = d.month;
    year = d.year;
}

bool date::isBissextile() {
    return year % 4 == 0 && year % 100 != 0 || year % 400 == 0;
}

int date::getWday() {
    int sd=1; date date1(1,1,1900); // Monday
    if( *this<date1 ){
        while( *this!=date1 ){
            date1.decrement();
            sd = (sd==0) ? 6 : sd-1;
        }
    }else{
        while( *this!=date1 ){
            date1.increment();
            sd = (sd==6) ? 0 : sd+1;
        }
    }
    return sd;
}

void date::PrintDate() {
    string Days[] = {"Dimanche", "Lundi", "Mardi", "Mercredi", "Jeudi", "Vendredi", "Samedi"};
    string Months[] = {"Janvier", "Fevrier", "Mars", "Avril", "Mai", "Juin", "Juillet", "Aout", "Septembre", "Octobre", "Novembre",
                       "Decembre"};
    int tm_wday = getWday();  // days since sunday
    cout << Days[tm_wday] << " " << day << " " << Months[month - 1] << " " << year << endl;
}

void date::increment() {
    if (month == 12 && day == months_days[month - 1]) {
        setYear(year+1);
        month = 1;
        day = 1;
    }
    else if (day == months_days[month - 1]) {
        month++;
        day = 1;
    }
    else
        day++;
}

date date::operator+=(int d) {
    while (d > 0) {
        increment();
        d--;
    }
    return *this;
}

date date::operator+(int d) {
    date date1(day, month, year);
    return date1 += d;
}

void date::decrement() {
    if (month == 1 && day == 1) {
        setYear(year-1);
        month = 12;
        day = months_days[month - 1];
    }
    else if (day == 1) {
        month--;
        day = months_days[month - 1];
    }
    else
        day--;
}

date date::operator-=(int d) {
    while (d > 0 && year > 0) {
        decrement();
        d--;
    }
    return *this;
}

date date::operator-(int d) {
    date date1(day, month, year);
    return date1 -= d;
}

date date::operator--() {
    decrement();
    return *this;
}

date date::operator++() {
    increment();
    return *this;
}

date date::operator--(int) {
    date date1 = *this;
    decrement();
    return date1;
}

date date::operator++(int) {
    date date1 = *this;
    increment();
    return date1;
}

bool date::operator==(date const &d) {
    return year == d.year && month == d.month && day == d.day;
}

bool date::operator!=(date const &d) {
    return !(*this == d);
}

bool date::operator<(date const &d) {
    if (year == d.year) if (month == d.month)
        return day < d.day;
    else return month < d.month;
    else return year < d.year;
}

bool date::operator<=(date const &d) {
    return *this < d || *this == d;
}

bool date::operator>(date const &d) {
    return !(*this <= d);
}

bool date::operator>=(date const &d) {
    return !(*this < d);
}

int date::operator-(date const &d) {
    date date1(d);
    int res = 0;
    if (*this > date1) {
        while (date1 != *this) {
            date1.increment();
            res++;
        }
    } else {
        while (date1 != *this) {
            date1.decrement();
            res++;
        }
    }
    return res;
}

ostream &operator<<(ostream &out, date const &d) {
    out << d.day << "/" << d.month << "/" << d.year;
    return out;
}

void date::init() {
    months_days = new int[12];
    months_days[0]=31; months_days[1]=(isBissextile()) ? 29 : 28; months_days[2]=31; months_days[3]=30;
    months_days[4]=31; months_days[5]=30; months_days[6]=31; months_days[7]=31;
    months_days[8]=30; months_days[9]=31; months_days[10]=30; months_days[11]=31;
    year = month = day = 1;
}

void date::update_months_days() {
    months_days[1]=(isBissextile()) ? 29 : 28;
}