#include "grid.h"
#include "snake.h"

void crawl(Snake *snake, Grid *g)
{
    int i;
    Coord new_head = snake->pos[0];
    switch (snake->dir)
    {
    case LEFT:
        new_head.x = (new_head.x - 1 + g->nbc) % g->nbc;
        break;
    case RIGHT:
        new_head.x = (new_head.x + 1) % g->nbc;
        break;
    case TOP:
        new_head.y = (new_head.y - 1 + g->nbl) % g->nbl;
        break;
    case BOTTOM:
        new_head.y = (new_head.y + 1) % g->nbl;
        break;
    }

    for (i = SNAKE_SIZE - 1; i > 0; i--)
    {
        snake->pos[i] = snake->pos[i - 1];
    }

    snake->pos[0] = new_head;
}