#include <SDL.h>
#include <SDL_image.h>

typedef enum Type {
    PLAYER1, PLAYER2, BULLET
} Type;

typedef struct Entity {
    SDL_Texture *texture;
    Type type;
    float x, y, w, h;
} Entity;

typedef struct Bullet {
    Entity e;
    int lifeTime;
} Bullet;

typedef struct Node {
    Entity e;
    struct Node *next;
} Node;

Entity* addEntity(Node **head, float x, float y, float w, float h, SDL_Texture *texture, Type type) {
    Node *new;
    new = malloc(sizeof(Node));
    new->e.x = x;
    new->e.y = y;
    new->e.w = w;
    new->e.h = h;
    new->e.type = type;
    new->e.texture = texture;
    new->next = *head;
    if (type == BULLET) {
        ((Bullet*)new)->lifeTime = 500;
    }
    *head = new;
    return &(*head)->e;
}

void removeEntity(Node **head, Entity *e) {
    if (*head == NULL) {
        return;
    }
    if (&(*head)->e == e) {
        Node *tempnext = (*head)->next;
        SDL_DestroyTexture((*head)->e.texture);
        free(*head);
        *head = tempnext;
        return;
    }
    Node *temp = *head;
    Node *previous = *head;
    while (temp != NULL) {
        if (&temp->e == e) {
            previous->next = temp->next;
            SDL_DestroyTexture(temp->e.texture);
            free(&(*temp));
            return;
        }
        previous = temp;
        temp = temp->next;
    }
}

int main(int argc, char **argv) {
    int running = 1;
    SDL_Event event;

    SDL_Init(SDL_INIT_EVERYTHING);
    IMG_Init(IMG_INIT_PNG);

    SDL_Window *window = SDL_CreateWindow("Hello, SDL2", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, 800, 600, SDL_WINDOW_OPENGL);

    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED | SDL_RENDERER_PRESENTVSYNC);

    SDL_Surface *crab = IMG_Load("crab.png");
    SDL_Surface *cmder = IMG_Load("cmder.png");

    SDL_SetRenderDrawColor(renderer, 0, 0, 0, 255);

    Node *head = NULL;

    addEntity(&head, 32, 32, 160, 128, SDL_CreateTextureFromSurface(renderer, crab), PLAYER1);
    addEntity(&head, 256, 256, 160, 128, SDL_CreateTextureFromSurface(renderer, cmder), PLAYER2);

    while (running) {
        while (SDL_PollEvent(&event)) {
            if (event.type == SDL_QUIT) {
                running = 0;
            }
        }

        SDL_RenderClear(renderer);
        const Uint8 *state = SDL_GetKeyboardState(NULL);

        if (state[SDL_SCANCODE_ESCAPE]) {
            running = 0;
        }

        Node *tmp = head;
        while (tmp != NULL) {
            if (state[SDL_SCANCODE_SPACE]) {
                if (tmp->e.type == PLAYER1) {
                    addEntity(&head, tmp->e.x, tmp->e.y, 16, 16, SDL_CreateTextureFromSurface(renderer, cmder), BULLET);
                }
            }
            if (tmp->e.type == BULLET) {
                tmp->e.x += 4;
                SDL_Log("%d", ((Bullet*) (&tmp->e))->lifeTime);
            }
            SDL_Rect dst = {tmp->e.x, tmp->e.y, tmp->e.w, tmp->e.h};
            SDL_RenderCopy(renderer, tmp->e.texture, NULL, &dst);
            tmp = tmp->next;
        }

        SDL_RenderPresent(renderer);
    }

    SDL_FreeSurface(crab);
    SDL_FreeSurface(cmder);
    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    IMG_Quit();
    SDL_Quit();

    return 0;
}