#include "snake.h"
#include <stdlib.h>

struct snake* add_snake(struct snake* snake, int x, int y) {
    struct snake* hlava = malloc(sizeof(struct snake));
    if (hlava == NULL) return NULL;
    hlava->x = x;
    hlava->y = y;
    hlava->next = snake;
    return hlava;
}

struct snake* remove_snake(struct snake* snake) {
    if (!snake) return NULL;
    
    struct snake* current = snake;
    struct snake* previous = NULL;

    while (current->next) {
        previous = current;
        current = current->next;
    }

    if (previous) {
        previous->next = NULL;
    } else {
        free(current);
        return NULL;
    }

    free(current);
    return snake;
}

void free_snake(struct snake* sn){
}

int is_snake(struct snake* snake, int x, int y) {
    while (snake) {
        if (snake->x == x && snake->y == y) return 1;
        snake = snake->next;
    }
    return 0;
}

int step_state(struct state* st){
	int nx = (st->snake->x + st->sx);
    int ny = (st->snake->y + st->sy);
    return END_CONTINUE;
}