#include <SDL2/SDL.h>
#include <stdbool.h>

#define SCREEN_WIDTH 800
#define SCREEN_HEIGHT 600

typedef struct {
    int x, y;
    int width, height;
    int speed;
} Ship;

typedef struct {
    int x, y;
    int speed;
    bool active;
} Bullet;

void initShip(Ship* ship) {
    ship->x = SCREEN_WIDTH / 2;
    ship->y = SCREEN_HEIGHT - 50;
    ship->width = 40;
    ship->height = 40;
    ship->speed = 5;
}

void initBullet(Bullet* bullet) {
    bullet->x = 0;
    bullet->y = 0;
    bullet->speed = 10;
    bullet->active = false;
}

void moveShip(Ship* ship, const Uint8* keystates) {
    if (keystates[SDL_SCANCODE_LEFT] && ship->x > 0) {
        ship->x -= ship->speed;
    }
    if (keystates[SDL_SCANCODE_RIGHT] && ship->x < SCREEN_WIDTH - ship->width) {
        ship->x += ship->speed;
    }
    if (keystates[SDL_SCANCODE_UP] && ship->y > 0) {
        ship->y -= ship->speed;
    }
    if (keystates[SDL_SCANCODE_DOWN] && ship->y < SCREEN_HEIGHT - ship->height) {
        ship->y += ship->speed;
    }
}

void shootBullet(Bullet* bullet, Ship* ship) {
    if (!bullet->active) {
        bullet->x = ship->x + ship->width / 2;
        bullet->y = ship->y;
        bullet->active = true;
    }
}

void updateBullet(Bullet* bullet) {
    if (bullet->active) {
        bullet->y -= bullet->speed;
        if (bullet->y < 0) {
            bullet->active = false;
        }
    }
}

void renderShip(SDL_Renderer* renderer, Ship* ship) {
    SDL_Rect rect = { ship->x, ship->y, ship->width, ship->height };
    SDL_SetRenderDrawColor(renderer, 0, 255, 0, 255);
    SDL_RenderFillRect(renderer, &rect);
}

void renderBullet(SDL_Renderer* renderer, Bullet* bullet) {
    if (bullet->active) {
        SDL_Rect rect = { bullet->x, bullet->y, 5, 10 };
        SDL_SetRenderDrawColor(renderer, 255, 255, 0, 255);
        SDL_RenderFillRect(renderer, &rect);
    }
}

int main(int argc, char* args[]) {
    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
        printf("SDL could not initialize! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }

    SDL_Window* window = SDL_CreateWindow("Thunder Fighter", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_SHOWN);
    if (window == NULL) {
        printf("Window could not be created! SDL_Error: %s\n", SDL_GetError());
        return -1;
    }

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

    Ship ship;
    Bullet bullet;
    initShip(&ship);
    initBullet(&bullet);

    bool quit = false;
    SDL_Event e;

    while (!quit) {
        const Uint8* keystates = SDL_GetKeyboardState(NULL);
        while (SDL_PollEvent(&e) != 0) {
            if (e.type == SDL_QUIT) {
                quit = true;
            }
            if (e.type == SDL_KEYDOWN) {
                if (e.key.keysym.sym == SDLK_SPACE) {
                    shootBullet(&bullet, &ship);
                }
            }
        }

        moveShip(&ship, keystates);
        updateBullet(&bullet);

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

        renderShip(renderer, &ship);
        renderBullet(renderer, &bullet);

        SDL_RenderPresent(renderer);

        SDL_Delay(16); // 60 frames per second
    }

    SDL_DestroyRenderer(renderer);
    SDL_DestroyWindow(window);
    SDL_Quit();

    return 0;
}