/*
 * Copyright 2019, Cypress Semiconductor Corporation or a subsidiary of
 * Cypress Semiconductor Corporation. All Rights Reserved.
 * 
 * This software, associated documentation and materials ("Software")
 * is owned by Cypress Semiconductor Corporation,
 * or one of its subsidiaries ("Cypress") and is protected by and subject to
 * worldwide patent protection (United States and foreign),
 * United States copyright laws and international treaty provisions.
 * Therefore, you may use this Software only as provided in the license
 * agreement accompanying the software package from which you
 * obtained this Software ("EULA").
 * If no EULA applies, Cypress hereby grants you a personal, non-exclusive,
 * non-transferable license to copy, modify, and compile the Software
 * source code solely for use in connection with Cypress's
 * integrated circuit products. Any reproduction, modification, translation,
 * compilation, or representation of this Software except as specified
 * above is prohibited without the express written permission of Cypress.
 *
 * Disclaimer: THIS SOFTWARE IS PROVIDED AS-IS, WITH NO WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, NONINFRINGEMENT, IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cypress
 * reserves the right to make changes to the Software without notice. Cypress
 * does not assume any liability arising out of the application or use of the
 * Software or any product or circuit described in the Software. Cypress does
 * not authorize its products for use in any products where a malfunction or
 * failure of the Cypress product may reasonably be expected to result in
 * significant property damage, injury or death ("High Risk Product"). By
 * including Cypress's product in a High Risk Product, the manufacturer
 * of such system or application assumes all risk of such use and in doing
 * so agrees to indemnify Cypress against all liability.
 */


/** @file
 * Functions to read/write Type-Length-Value (TLV) data used in many common protocols.
 */

#ifndef INCLUDED_TLV_H
#define INCLUDED_TLV_H

#include <stdint.h>

/******************************************************
 *                      Macros
 ******************************************************/

/******************************************************
 *                    Constants
 ******************************************************/

/******************************************************
 *                   Enumerations
 ******************************************************/

typedef enum
{
    TLV_UINT8     = 1,
    TLV_UINT16    = 2,
    TLV_UINT32    = 3,
    TLV_CHAR_PTR  = 4,
    TLV_UINT8_PTR = 5,
} tlv_data_type_t;

typedef enum
{
    TLV_SUCCESS,
    TLV_NOT_FOUND
} tlv_result_t;


/******************************************************
 *                 Type Definitions
 ******************************************************/

#pragma pack(1)

/* Structures for TLVs with 16-bit type and 16-bit length */
typedef struct
{
    uint16_t type;
    uint16_t length;
} tlv16_header_t;

typedef struct
{
    uint16_t type;
    uint16_t length;
    uint8_t data;
} tlv16_uint8_t;

typedef struct
{
    uint16_t type;
    uint16_t length;
    uint16_t data;
} tlv16_uint16_t;

typedef struct
{
    uint16_t type;
    uint16_t length;
    uint32_t data;
} tlv16_uint32_t;

typedef struct
{
    uint16_t type;
    uint16_t length;
    uint8_t data[1];
} tlv16_data_t;

/* Structures for TLVs with 8-bit type and 8-bit length */
typedef struct
{
    uint8_t type;
    uint8_t length;
} tlv8_header_t;

typedef struct
{
    uint8_t type;
    uint8_t length;
    uint8_t data;
} tlv8_uint8_t;

typedef struct
{
    uint8_t type;
    uint8_t length;
    uint16_t data;
} tlv8_uint16_t;

typedef struct
{
    uint8_t type;
    uint8_t length;
    uint32_t data;
} tlv8_uint32_t;

typedef struct
{
    uint8_t type;
    uint8_t length;
    uint8_t data[1];
} tlv8_data_t;

#pragma pack()

#ifdef __cplusplus
extern "C" {
#endif

/** Finds a particular type from a buffer of TLV data.
 *
 * Returns a pointer to the first TLV which has a type that matches the given type.
 * The pointer points to the 'type' field.
 * This is the 8-bit-Type & 8-bit-Lenght version
 *
 * @param[in] message        : A pointer to the source TLV data to be searched
 * @param[in] message_length : The length of the source TLV data to be searched
 * @param[in] type           : The TLV type to search for
 *
 * @return Pointer to start of first matching TLV, or NULL if not found
 */
tlv8_data_t*  tlv_find_tlv8    ( const uint8_t* message, uint32_t message_length, uint8_t type );

/** Finds a particular type from a buffer of TLV data.
 *
 * Returns a pointer to the first TLV which has a type that matches the given type.
 * The pointer points to the 'type' field.
 * This is the 16-bit-Type & 16-bit-Lenght version
 *
 * @param[in] message        : A pointer to the source TLV data to be searched
 * @param[in] message_length : The length of the source TLV data to be searched
 * @param[in] type           : The TLV type to search for
 *
 * @return Pointer to start of first matching TLV, or NULL if not found
 */
tlv16_data_t* tlv_find_tlv16   ( const uint8_t* message, uint32_t message_length, uint16_t type );
uint8_t*      tlv_write_header ( uint8_t* buffer, uint16_t type, uint16_t length );
tlv_result_t  tlv_read_value   ( uint16_t type, const uint8_t* message, uint16_t message_length, void* value, uint16_t value_size, tlv_data_type_t data_type );
uint8_t*      tlv_write_value  ( uint8_t* buffer, uint16_t type, uint16_t length, const void* data, tlv_data_type_t data_type );

#ifdef __cplusplus
} /*extern "C" */
#endif

#endif /* INCLUDED_TLV_H */