#include <SDL2/SDL_render.h>
#include <stdbool.h>
#include <vectorlib.c>

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

#define PROJECT_NAME "vectors-drag"
#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 DragC = 0.2;

#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), 100, RandomFloat(1, 8));
    }
}

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

void applyForce(OBJECT_INER *obj, Point force){
    point_div(&force, &(Point){obj->mass,obj->mass});
    point_add(&obj->acc, &force);
}

void drag(STUFFS *stuff, OBJECT_INER *obj, float c){
    // something something velocity is 0 objects goto corner idk why
    if(magnitude(obj->vel.x, obj->vel.y) != 0){
        Point drag = { obj->vel.x, obj->vel.y, };
        point_set_mag(&drag, 1.0);
        point_mul(&drag,&(Point){-1,-1});

        float speed = magnitude(obj->vel.x, obj->vel.y);
        point_set_mag(&drag, c * (speed * speed));

        applyForce(obj, drag);
    }
}

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

    circleRGBA(renderer, x, y, obj->r, 190, 90, 255, 255);
    filledCircleRGBA(renderer, x, y, obj->r, 150, 50, 255, 80);
}

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

    //SDL_SetRenderDrawColor(renderer,0,0,0,255);
    //SDL_RenderFillRect(renderer, &(SDL_Rect){0,0,stuff->width,stuff->height});

    SDL_SetRenderDrawColor(renderer,255,255,255,90);
    SDL_RenderFillRect(renderer, &(SDL_Rect){0,stuff->height/2,stuff->width,stuff->height});

    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);

        if(stuff->obj.objs[i]->pos.y > (float)stuff->height/2){
            drag(stuff,stuff->obj.objs[i],DragC);
        }

        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>


/* Exercises
 *
 * make a liquid class/object that
 * describes a density
 * coefficient
 * and area of where that liquid or gas is
 *
 * Surface Area
 */