#include "snake.h"
#include <stdlib.h>
#include <stdio.h>
struct snake* add_snake(struct snake* snake, int x, int y) {
    struct snake* head = calloc(1, sizeof(struct snake));
    head->x = x;
    head->y = y;
    head->next = snake;
    return head;
}

struct snake* remove_snake(struct snake* snake) {
 if (snake == NULL || snake->next == NULL) {
        free(snake);
        return NULL;
    }
    struct snake* current = snake;
    struct snake* prev = NULL;
    while (current->next != NULL) {
        prev = current;
        current = current->next;
    }
    free(current);
    current = NULL;
    prev->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) {
    while (snake != NULL) {
        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);
    int count = 0;
    //int county = 0;
    if (nx < 0 || nx >= st->width || ny < 0 || ny >= st->height) {
        return END_WALL;
    }
    if (is_snake(st->snake->next, nx, ny)) {
        return END_SNAKE;
   	}
    for (int i = 0; i < FOOD_COUNT; i++) {
        if (nx == st->foodx[i] && ny == st->foody[i]) {
            st->snake = add_snake(st->snake, nx, ny);
            st->foodx[i] = -1;
            st->foody[i] = -1;
            }
    }
    for (int i = 0; i < FOOD_COUNT; i++) {
if (st->foodx[i] == -1 && st->foody[i] == -1) {
count++;
if(count == 5){
return END_FOOD;
}
}
}
    st->snake = add_snake(st->snake, nx, ny);
    st->snake = remove_snake(st->snake);
    return END_CONTINUE;
}