/*
 * Copyright (c) 2014-2020 Pavel Kalvoda <me@pavelkalvoda.com>
 *
 * libcbor is free software; you can redistribute it and/or modify
 * it under the terms of the MIT license. See LICENSE for details.
 */

#ifndef LIBCBOR_TAGS_H
#define LIBCBOR_TAGS_H

#include "cbor/cbor_export.h"
#include "cbor/common.h"

#ifdef __cplusplus
extern "C" {
#endif

/*
 * ============================================================================
 * Tag manipulation
 * ============================================================================
 */

/** Create a new tag.
 *
 * @param value The tag value (number).
 * @return Reference to the new tag. Its reference count is initialized to one
 * and it points to a `NULL` item.
 * @return `NULL` if memory allocation fails.
 */
_CBOR_NODISCARD CBOR_EXPORT cbor_item_t* cbor_new_tag(uint64_t value);

/** Get the tagged item (what the tag points to).
 *
 * @param tag A #CBOR_TYPE_TAG tag.
 * @return Reference to the tagged item, which may be `NULL` if no item has
 * been set yet.
 *
 * If non-NULL, increases the reference count of the underlying item. The
 * returned reference must be released using #cbor_decref.
 */
_CBOR_NODISCARD CBOR_EXPORT cbor_item_t* cbor_tag_item(const cbor_item_t* tag);

/** Get the tag value.
 *
 * @param tag A #CBOR_TYPE_TAG tag.
 * @return The tag value (number).
 */
_CBOR_NODISCARD CBOR_EXPORT uint64_t cbor_tag_value(const cbor_item_t* tag);

/** Assign a tag to an item.
 *
 * @param tag A #CBOR_TYPE_TAG tag.
 * @param tagged_item The item to tag. Its reference count will be increased
 * by one.
 *
 * If the tag already points to an item, the previous item's reference count
 * will be decreased by one.
 */
CBOR_EXPORT void cbor_tag_set_item(cbor_item_t* tag, cbor_item_t* tagged_item);

/** Build a new tag.
 *
 * @param item The item to tag. Its reference count will be increased by
 * one.
 * @param value The tag value (number).
 * @return Reference to the new tag item. The item's reference count is
 * initialized to one.
 * @return `NULL` if memory allocation fails.
 */
_CBOR_NODISCARD CBOR_EXPORT cbor_item_t* cbor_build_tag(uint64_t value,
                                                        cbor_item_t* item);

#ifdef __cplusplus
}
#endif

#endif  // LIBCBOR_TAGS_H