/** @file
 *  @brief Attribute Protocol handling.
 */

/*
 * Copyright (c) 2016 Intel Corporation
 *
 * SPDX-License-Identifier: Apache-2.0
 */
#ifndef ZEPHYR_INCLUDE_BLUETOOTH_ATT_H_
#define ZEPHYR_INCLUDE_BLUETOOTH_ATT_H_

/**
 * @brief Attribute Protocol (ATT)
 * @defgroup bt_att Attribute Protocol (ATT)
 * @ingroup bluetooth
 * @{
 */

#include <zephyr/sys/slist.h>
#include <zephyr/bluetooth/conn.h>

#ifdef __cplusplus
extern "C" {
#endif

/* Error codes for Error response PDU */
#define BT_ATT_ERR_SUCCESS			0x00
#define BT_ATT_ERR_INVALID_HANDLE		0x01
#define BT_ATT_ERR_READ_NOT_PERMITTED		0x02
#define BT_ATT_ERR_WRITE_NOT_PERMITTED		0x03
#define BT_ATT_ERR_INVALID_PDU			0x04
#define BT_ATT_ERR_AUTHENTICATION		0x05
#define BT_ATT_ERR_NOT_SUPPORTED		0x06
#define BT_ATT_ERR_INVALID_OFFSET		0x07
#define BT_ATT_ERR_AUTHORIZATION		0x08
#define BT_ATT_ERR_PREPARE_QUEUE_FULL		0x09
#define BT_ATT_ERR_ATTRIBUTE_NOT_FOUND		0x0a
#define BT_ATT_ERR_ATTRIBUTE_NOT_LONG		0x0b
#define BT_ATT_ERR_ENCRYPTION_KEY_SIZE		0x0c
#define BT_ATT_ERR_INVALID_ATTRIBUTE_LEN	0x0d
#define BT_ATT_ERR_UNLIKELY			0x0e
#define BT_ATT_ERR_INSUFFICIENT_ENCRYPTION	0x0f
#define BT_ATT_ERR_UNSUPPORTED_GROUP_TYPE	0x10
#define BT_ATT_ERR_INSUFFICIENT_RESOURCES	0x11
#define BT_ATT_ERR_DB_OUT_OF_SYNC		0x12
#define BT_ATT_ERR_VALUE_NOT_ALLOWED		0x13

/* Common Profile Error Codes (from CSS) */
#define BT_ATT_ERR_WRITE_REQ_REJECTED		0xfc
#define BT_ATT_ERR_CCC_IMPROPER_CONF		0xfd
#define BT_ATT_ERR_PROCEDURE_IN_PROGRESS	0xfe
#define BT_ATT_ERR_OUT_OF_RANGE			0xff

/* Version 5.2, Vol 3, Part F, 3.2.9 defines maximum attribute length to 512 */
#define BT_ATT_MAX_ATTRIBUTE_LEN		512

/* Handle 0x0000 is reserved for future use */
#define BT_ATT_FIRST_ATTRIBUTE_HANDLE           0x0001
#define BT_ATT_FIRST_ATTTRIBUTE_HANDLE __DEPRECATED_MACRO BT_ATT_FIRST_ATTRIBUTE_HANDLE
/* 0xffff is defined as the maximum, and thus last, valid attribute handle */
#define BT_ATT_LAST_ATTRIBUTE_HANDLE            0xffff
#define BT_ATT_LAST_ATTTRIBUTE_HANDLE __DEPRECATED_MACRO BT_ATT_LAST_ATTRIBUTE_HANDLE

#if defined(CONFIG_BT_EATT)
#if defined(CONFIG_BT_TESTING)

int bt_eatt_disconnect_one(struct bt_conn *conn);

/* Reconfigure all EATT channels on connection */
int bt_eatt_reconfigure(struct bt_conn *conn, uint16_t mtu);

#endif /* CONFIG_BT_TESTING */

/** @brief Connect Enhanced ATT channels
 *
 * Sends a series of Credit Based Connection Requests to connect @p num_channels
 * Enhanced ATT channels. The peer may have limited resources and fewer channels
 * may be created.
 *
 * @param conn The connection to send the request on
 * @param num_channels The number of Enhanced ATT beares to request.
 * Must be in the range 1 - @kconfig{CONFIG_BT_EATT_MAX}, inclusive.
 *
 * @return 0 in case of success or negative value in case of error.
 * @retval -EINVAL if @p num_channels is not in the allowed range or @p conn is NULL.
 * @retval -ENOMEM if less than @p num_channels are allocated.
 * @retval 0 in case of success
 */
int bt_eatt_connect(struct bt_conn *conn, size_t num_channels);

/** @brief Get number of EATT channels connected.
 *
 * @param conn The connection to get the number of EATT channels for.
 *
 * @return The number of EATT channels connected.
 * Returns 0 if @p conn is NULL or not connected.
 */
size_t bt_eatt_count(struct bt_conn *conn);

#endif /* CONFIG_BT_EATT */

/** @brief ATT channel option bit field values.
 * @note @ref BT_ATT_CHAN_OPT_UNENHANCED_ONLY and @ref BT_ATT_CHAN_OPT_ENHANCED_ONLY are mutually
 * exclusive and both bits may not be set.
 */
enum bt_att_chan_opt {
	/** Both Enhanced and Unenhanced channels can be used  */
	BT_ATT_CHAN_OPT_NONE = 0x0,
	/** Only Unenhanced channels will be used  */
	BT_ATT_CHAN_OPT_UNENHANCED_ONLY = BIT(0),
	/** Only Enhanced channels will be used  */
	BT_ATT_CHAN_OPT_ENHANCED_ONLY = BIT(1),
};

#ifdef __cplusplus
}
#endif

/**
 * @}
 */

#endif /* ZEPHYR_INCLUDE_BLUETOOTH_ATT_H_ */