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

struct snake* add_snake(struct snake* snake,int x,int y){
    struct snake* head = calloc(1,sizeof(struct snake));
    if (head == NULL) {
    return NULL;
    }
    head->x = x;
    head->y = y;
    head->next = snake;
    return head;
}

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

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

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