#include <emscripten/bind.h>

// Bring Emscripten namespace into scope for the sake of readability
using namespace emscripten;

class Vertex
{
    double x;
    double y;

public:

    Vertex(int x, int y): x(x), y(y)
    {}

    double getX() const { return this->x; } // <--- Getters for 'properties' must be 'const' methods.
    void setX(double x) { this->x = x; }    //      Notice how this is different from returning a const
    double getY() const { return this->y; } //      value. 'const' keyword declared this way tells the compiler
                                            //      to throw an error if any attributes get changed inside of the method

    void setY(double y) { this->y = y; }

    void invert()
    {
        x = -x;
        y = -y;
    }

    static Vertex VertexFactory(double x, double y)
    {
        return Vertex(x, y);
    }
};


EMSCRIPTEN_BINDINGS(Module) {
    class_<Vertex>("Vertex")
        .constructor<double, double>()  // <--- Register contructor that takes 2 doubles as arguments. You can also do '.constructor(&func)' to register an external function as a constructor
        .property("x", &Vertex::getX, &Vertex::setX) // <-- Register a 'property'. 'Properties' are JS variables
        .property("y", &Vertex::getY, &Vertex::setY) //     that call getters and setters when a variable is accessed.
                                                     //     So when 'Vertex.x = 4' is called, setX() will be called to
                                                     //     mutate 'x'
        .function("invert", &Vertex::invert) // <-- Register an instance function (ie. a function that is called per instance)
        .class_function("VertexFactory", &Vertex::VertexFactory); // <-- Register a static function
                                                                  //     (ie. a function that can be directly called
                                                                  //      from the class)
}