#include <iostream>
#include <memory>
#include <vector>

using namespace std;

class Shape {
public:
    virtual void draw() = 0;
    virtual ~Shape() {};
};

class Circle : public Shape {
    int x;
    int y;
    int r;
public:
    Circle(int x, int y, int r) : x(x), y(y), r(r) {}

    virtual void draw() {
        cout << "draw circle: " << x << " " << y << " " << r << endl;
    }
};

class Square : public Shape{
    int x1;
    int y1;
    int x2;
    int y2;
public:
    Square(int x1, int y1, int x2, int y2) : x1(x1), y1(y1), x2(x2), y2(y2) {}

    virtual void draw() {
        cout << "draw square: " << x1 << " " << y1 << " " << x2 << " " << y2 << endl;
    }
};


class Factory {
public:
    virtual unique_ptr<Shape> generate(vector<int>& v) = 0;
};

class SquareFactory : public Factory {
public:
    virtual unique_ptr<Shape> generate(vector<int>& v) override {
        return make_unique<Square>(v[0], v[1], v[2], v[3]);
    }
};

class CircleFactory : public Factory {
public:
    virtual unique_ptr<Shape> generate(vector<int>& v) override {
        return make_unique<Circle>(v[0], v[1], v[2]);
    }
};

// A simple version of Simple Factory
unique_ptr<Factory> choose_factory(string s) {
    if (s == "circle") {
        return make_unique<CircleFactory>();
    } else if (s == "square") {
        return make_unique<SquareFactory>();
    }

    return nullptr;
}

int main() {
    auto f = choose_factory("circle");
    // Getting factory and generating object is decoupled here.
    vector<int> v = {1, 2, 3};
    auto s = f->generate(v);
    s->draw();

    f = choose_factory("square");
    v.push_back(4);
    s = f->generate(v);
    s->draw();
}