#include <stdbool.h>
#include <vectorlib.c>

#include <SDL2/SDL.h>
#include <SDL2/SDL_video.h>
#include <SDL2/SDL2_gfxPrimitives.h>

#define PROJECT_NAME "vectors-friction"
#define obj_n 10

typedef struct OBJECT_INER {
    Point pos;
    Point vel;
    Point acc;
    float r;
    float mass;
} OBJECT_INER;

typedef struct OBJECT {
    OBJECT_INER *objs[obj_n];
} OBJECT;

float mu=0.1;

#include <init.h>

void constructor(int w, int h, OBJECT_INER *obj, float x, float y, float mass){
    obj->pos.x = x;
    obj->pos.y = y;
    obj->vel = (Point){0,0};
    obj->acc = (Point){0,0};
    obj->mass = mass;
    obj->r = sqrt(obj->mass) * 10;
}

void init_stuffs(int w, int h, OBJECT_INER *objs, STUFFS *stuff){
    for (int i=0; i<obj_n; i++){
        constructor(w, h, &objs[i], RandomFloat(0, w), 200, RandomFloat(1, 8));
    }
}

Point vec_sub(Point A, Point B){
    point_sub(&A, &B);
    return A;
}

void applyForce(OBJECT_INER *obj, Point force){
    //no need to make a copy. tis not a pointer
    point_div(&force, &(Point){obj->mass,obj->mass});
    point_add(&obj->acc, &force);
}

void friction(STUFFS *stuff, OBJECT_INER *obj){
    int diff = stuff->height - (obj->pos.y + obj->r);
    if (diff < 1){
        //will ignore mass
        //point_mul(&obj->vel,&(Point){0.95,0.95});

        // Direction of Friction
        Point friction = { obj->vel.x, obj->vel.y, };
        point_set_mag(&friction, 1.0);
        point_mul(&friction,&(Point){-1,-1});

        // Magnitude of Friction
        float normal = obj->mass;
        point_set_mag(&friction, mu * normal);

        applyForce(obj, friction);
    }
}

void edges(STUFFS *stuff, OBJECT_INER *obj) {
    if (obj->pos.y >= stuff->height - obj->r){
        obj->pos.y = stuff->height - obj->r;
        obj->vel.y = obj->vel.y * -1;
    }

    if (obj->pos.x >= stuff->width - obj->r){
        obj->pos.x = stuff->width - obj->r;
        obj->vel.x = obj->vel.x * -1;
    } else if (obj->pos.x <= obj->r){
        obj->pos.x = obj->r;
        obj->vel.x = obj->vel.x * -1;
    }
}

void update(STUFFS *stuff, OBJECT_INER *obj){
    point_add(&obj->vel,&obj->acc);
    point_add(&obj->pos, &obj->vel);
    obj->acc = (Point){0,0};
}

void show(SDL_Renderer* renderer,STUFFS *stuff,OBJECT_INER *obj){
    SDL_SetRenderDrawColor(renderer,150,50,255,10);

    Sint16 x = (Sint16)obj->pos.x;
    Sint16 y = (Sint16)obj->pos.y;

    filledCircleRGBA(renderer, x, y, obj->r, 150, 50, 255, 255);
}

void draw(SDL_Renderer* renderer,SDL_Window* window, STUFFS *stuff){
    SDL_SetRenderDrawColor(renderer,0,0,0,255);
    SDL_RenderClear(renderer);

    for (int i=0; i<obj_n; i++){
        Point gravity = {0, 0.2};
        Point weight = {0};

        weight.x = gravity.x * stuff->obj.objs[i]->mass;
        weight.y = gravity.y * stuff->obj.objs[i]->mass;
        if(stuff->mousedown == true){
            Point wind = {0.1, 0};
            applyForce(stuff->obj.objs[i], wind);
        }

        applyForce(stuff->obj.objs[i], weight);

        friction(stuff,stuff->obj.objs[i]);

        update(stuff,stuff->obj.objs[i]);
        edges(stuff,stuff->obj.objs[i]);
        show(renderer,stuff,stuff->obj.objs[i]);
    }

	SDL_RenderPresent(renderer);
}

void mousePressed(STUFFS *stuff){

}

#include <init.c>