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

int gcd(int a, int b) {

    while (b) {
        a %= b;
        int z = a;
        a = b;
        b = z;
    }

    return a;
}

int NOK(int a, int b)
{
    return a * b / gcd(a, b);
}

void FractionReduction(Rational& r) {
    int num = r.getNumenator();
    int denom = r.getDenominator();
    int c = gcd(num, denom);

    num /= c;
    denom /= c;

    r.setNumenator(num);
    r.setDenominator(denom);
}

Rational::Rational(int num, int denom) {
    numenator = num;
    denominator = denom;
    if (denominator == 0) {
        throw DivisionByZeroException("Division by zero exception");
    }

}

void Rational::setNumenator(int a) {
    numenator = a;
}

void Rational::setDenominator(int a) {
    denominator = a;
}

int Rational::getDenominator() const {
    return denominator;
}

int Rational::getNumenator() const {
    return numenator;
}

double Rational::getDouble() const {
    return static_cast<double> (numenator) / denominator;
}

std::ostream& operator<< (std::ostream& out, const Rational &rational) {
    out << rational.numenator << "/" << rational.denominator << std::endl;
    return out;
}

std::istream& operator>> (std::istream& in, Rational &rational) {
    in >> rational.numenator;
    in >> rational.denominator;
    rational = Rational(rational.numenator, rational.denominator);
    return in;
}

Rational& operator*=(Rational& r1, const Rational r2)
{
    int a = r1.getNumenator() *r2.getNumenator();
    int b = r1.getDenominator() * r2.getDenominator();
    r1.setNumenator(a);
    r1.setDenominator(b);
    FractionReduction(r1);
    return r1;
}

Rational& operator+=(Rational& r1, const Rational& r2) {
    int denom1 = r1.getDenominator();
    int denom2 = r2.getDenominator();
    int nok = NOK(denom1, denom2);

    denom1 = nok / denom1;
    denom2 = nok / denom2;

    int num = denom1 * r1.getNumenator() + denom2 * r2.getNumenator();

    r1.setNumenator(num);
    r1.setDenominator(nok);

    FractionReduction(r1);

    return r1;
}

bool operator==(const Rational& lhs, const Rational& rhs)
{
    if (lhs.getDouble() == rhs.getDouble()) {
        return true;
    }

    else {
        return false;
    }
}

bool operator>(const Rational& lhs, const Rational& rhs)
{
    if (lhs.getDouble() > rhs.getDouble()) {
        return true;
    }

    else {
        return false;
    }
}

Rational operator+(const Rational& r1, const Rational& r2) {
    Rational r;
    int denom1 = r1.getDenominator();
    int denom2 = r2.getDenominator();
    int nok = NOK(denom1, denom2);

    denom1 = nok / denom1;
    denom2 = nok / denom2;

    int num = denom1 * r1.getNumenator() + denom2 * r2.getNumenator();

    r.setNumenator(num);
    r.setDenominator(nok);

    FractionReduction(r);

    return r;
}

Rational operator*(const Rational& r1, const Rational& r2) {
    Rational r;

    int a = r1.getNumenator() * r2.getNumenator();
    int b = r1.getDenominator() * r2.getDenominator();

    r.setNumenator(a);
    r.setDenominator(b);

    FractionReduction(r);

    return r;
}

Rational& operator-(Rational& r)
{
    int a = r.getNumenator() * -1;

    r.setNumenator(a);

    return r;
}

DivisionByZeroException::DivisionByZeroException(std::string error)
    :m_error(error)
    {
    }
const char* DivisionByZeroException::getError(){ return m_error.c_str(); }

int main()
{
    try {
        /*Rational drob1(15, 3);
        FractionReduction(drob1);
        std::cout << drob1;*/
        /*Rational drob2(5, 4);*/
        /*std::cin >> drob;
        std::cout << drob;*/
        //std::cout << drob.getDouble();
        /*drob1 *= drob2;
        std::cout << drob1;*/
        /*bool equals = drob1 == drob2;
        bool less = drob1 > drob2;
        std::cout << less;*/
        /*std::cout << -drob1;*/
        Rational drob;
        Rational drob1(3,2);
        Rational drob2(1,2);
        drob = -drob2 + drob1;
        std::cout << drob;

    }
    catch (DivisionByZeroException& exception) {
        std::cerr << "A Rational exception  occured (" << exception.getError() << ")\n";
    }
}