/*
 * Copyright (c) 2026, Chloe M.
 * Provided under the BSD-3 clause
 */

#ifndef CESCAL_TOKBUF_H
#define CESCAL_TOKBUF_H 1

#include <stdint.h>
#include <stddef.h>
#include "cescal/token.h"

#define TOKBUF_CAP 4

struct tokbuf {
    struct token buf[TOKBUF_CAP];
    uint8_t head;
};

/*
 * Initialize the token buffer
 *
 * @tokbuf:  Token buffer to initialize
 *
 * Returns zero on success
 */
int tokbuf_init(struct tokbuf *tokbuf);

/*
 * Push a token onto the token buffer
 *
 * @tokbuf: Token buffer to push to
 * @tok:    Token to push
 *
 * Returns zero on success
 */
int tokbuf_push(struct tokbuf *tokbuf, struct token *tok);

/*
 * Peek at the token buffer from a negative offset backwards
 *
 * @tokbuf: Token buffer to read from
 * @noff:   Negative offset
 * @res:    Result is written here
 *
 * Returns zero on success
 */
int tokbuf_noff(struct tokbuf *tokbuf, size_t noff, struct token *res);

#endif  /* !CESCAL_TOKBUF_H */