#include <SFML/Graphics.hpp>
#include <iostream>
#include <unistd.h>
#include <cstdlib>
#include <math.h>

using namespace std;
using namespace sf;

#define Height 1000
#define Width 1500

#define dt 0.01
#define G 9.8

#define MAX_VY 15
#define u_water_0 (1.79*0.001)
#define u_water_25 (0.89*0.001)
#define u_water_100 (0.28*0.001)
#define u_glycerin (934*0.001)
#define u_mercury (1.554*0.001)
#define u_tar 10000000
#define u 0.00119


struct Circle {
    double R = rand()%26;
    Vector2f pos;
    Vector2f vel;
    double ro = (rand()%101 + 50)/(double)100;
    double V = (double)4/3*M_PI*R*R*R;
    double m = V*ro;
    bool sy = true, sx = true;
    int r= rand()%255;
    int g= rand()%255;
    int b= rand()%255;
};



void bouncing(Circle &circle) {
    Vector2f F(0, circle.m * G);

    Rect<float> fluid0(0, 0, Width/2 - circle.R, Height/2 - circle.R);

    if(fluid0.contains(circle.pos))
        F += circle.vel*(float)-6*(float)M_PI*(float)circle.R*(float)u_glycerin*(float)100;

    Vector2f a = F/(float)circle.m;

    // double ax = (F)/circle.m;

    // circle.vy = circle.vy + (ay)*dt;
    // circle.vx = circle.vx + (ax)*dt;
    circle.vel += a*(float)dt;
    circle.pos += circle.vel*(float)dt;

    //circle.x = circle.x + circle.vx*dt;
    //circle.y = circle.y + circle.vy*dt;

/*    if(circle.x<0 || circle.x > Width/2){
        double Dx = -6*M_PI*circle.R*circle.vx*u_glycerin*100;
        double Dy = -6*M_PI*circle.R*circle.vy*u_glycerin*100;
        double ay = (Dy+F)/circle.m;
        double ax = (Dx+F)/circle.m;
        circle.vy = circle.vy + (ay)*dt;
        circle.vx = circle.vx + (ax)*dt;

        circle.x = circle.x + circle.vx*dt;
        circle.y = circle.y + circle.vy*dt;
    }*/
    CircleShape shape(circle.R);
    shape.setPosition(circle.pos);

    // Rect<float> window( 0, 0, Width - circle.R, Height - circle.R);
    // if(!window.contains(circle.pos)) {
    //     circle.vel = -circle.vel;
    //     circle.sy = false;
    // } else circle.sy = true;

    if(circle.pos.y<0 || circle.pos.y > Height-2*circle.R) {
        if(circle.sy){
            circle.vel.y *= -1;
            circle.sy = false;
        }
    } else circle.sy = true;

    if(circle.pos.x<0 || circle.pos.x > Width-2*circle.R) {
        if(circle.sx){
            circle.vel.x *= -1;
            circle.sx = false;
        }
    } else circle.sx = true;
}



int main()
{
    sf::RenderWindow window(sf::VideoMode(Width, Height), "Bouncing balls");

    srand(time(NULL));
    int N = 50; //amount of balls
    Circle balls[N];

    RectangleShape fluid0_box(Vector2f(Width/2,Height/2));
    fluid0_box.setPosition(0,0);
    fluid0_box.setFillColor(Color(rand()%256, rand()%256, rand()%256));

    // Vector2f pos(Width/2-R, Height/2-R);
    //pos.x = Width/2-R;
    // pos.y = Height/2-R;

    for(int i=0; i<N; i++) {
        // balls[i].x=rand()%(int)(Width-2*balls[i].R);
        // balls[i].y=rand()%(int)(Height-2*balls[i].R);
        balls[i].pos = Vector2f(rand()%(int)(Width-2*balls[i].R), rand()%(int)(Height-2*balls[i].R));
        balls[i].vel = Vector2f(rand()%11-5, 0);
    }


    while (window.isOpen()){

        sf::Event event;
        while (window.pollEvent(event)){
            if (event.type == sf::Event::Closed)
                window.close();

            if( event.type == sf::Event::KeyPressed && event.key.code == sf::Keyboard::Escape )
                window.close();
        }

        window.clear();
        window.draw(fluid0_box);
        window.draw(fluid1_box);
        window.draw(fluid2_box);
        for(int i=0; i<N; i++) {
            bouncing(balls[i]);
            CircleShape shape(balls[i].R);
            shape.setFillColor(Color(balls[i].r, balls[i].g, balls[i].b));
            // shape.setPosition(balls[i].x, balls[i].y);
            shape.setPosition(balls[i].pos);
            window.draw(shape);
        }

        window.display();
        usleep(500);
    }

    return 0;
}