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

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

struct snake* remove_snake(struct snake* snake) {
    if (!snake || !snake->next) {
        free(snake);
        return NULL;
    }

    struct snake* current = snake;
    while (current->next->next) {
        current = current->next;
    }
    free(current->next);
    current->next = NULL;
    return snake;
}

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;
}

void free_snake(struct snake* sn) {
    while (sn) {
        struct snake* next = sn->next;
        free(sn);
        sn = next;
    }
}