/* Copyright 2019 Google LLC. All rights reserved. This file and proprietary */
/* source code may only be used and distributed under the Widevine Master */
/* License Agreement. */

#ifndef WIDEVINE_ODK_SRC_SERIALIZATION_BASE_H_
#define WIDEVINE_ODK_SRC_SERIALIZATION_BASE_H_

#ifdef __cplusplus
extern "C" {
#endif

#include <stddef.h>
#include <stdint.h>

#include "OEMCryptoCENCCommon.h"

#define SIZE_OF_MESSAGE_STRUCT 64

/*
 * Description:
 *   Point |msg| to stack-array |blk|.
 *   |blk| is guaranteed large enough to hold a |Message| struct.
 *   |blk| cannot be used in the same scope as a variable name.
 *   |msg| points to valid memory in the same scope |AllocateMessage| is used.
 * Parameters:
 *   msg: pointer to pointer to |Message| struct
 *   blk: variable name for stack-array
 */
#define AllocateMessage(msg, blk)      \
  uint8_t blk[SIZE_OF_MESSAGE_STRUCT]; \
  *(msg) = (Message*)(blk);

typedef struct _Message Message;

bool ValidMessage(Message* message);

void Pack_uint32_t(Message* message, const uint32_t* value);
void Pack_uint64_t(Message* message, const uint64_t* value);
void PackArray(Message* message, const uint8_t* base, size_t size);
void Pack_OEMCrypto_Substring(Message* msg, const OEMCrypto_Substring* obj);

void Unpack_uint32_t(Message* message, uint32_t* value);
void Unpack_uint64_t(Message* message, uint64_t* value);
void UnpackArray(Message* message, uint8_t* address,
                 size_t size); /* copy out */
void Unpack_OEMCrypto_Substring(Message* msg, OEMCrypto_Substring* obj);

typedef enum {
  MESSAGE_STATUS_OK,
  MESSAGE_STATUS_UNKNOWN_ERROR,
  MESSAGE_STATUS_OVERFLOW_ERROR,
  MESSAGE_STATUS_UNDERFLOW_ERROR,
  MESSAGE_STATUS_PARSE_ERROR,
  MESSAGE_STATUS_NULL_POINTER_ERROR,
  MESSAGE_STATUS_API_VALUE_ERROR
} MessageStatus;

/*
 * Create a message from a buffer. The message structure consumes the first
 * sizeof(Message) bytes of the buffer. The caller is responsible for ensuring
 * that the buffer remains allocated for the lifetime of the message.
 */
Message* CreateMessage(uint8_t* buffer, size_t buffer_size);

/*
 * Initialize a message structure to reference a separate buffer. The caller
 * is responsible for ensuring that the buffer remains allocated for the
 * lifetime of the message.
 */
void InitMessage(Message* message, uint8_t* buffer, size_t capacity);

/*
 * Reset an existing the message to an empty state
 */
void ResetMessage(Message* message);
uint8_t* GetBase(Message* message);
size_t GetCapacity(Message* message);
size_t GetSize(Message* message);
void SetSize(Message* message, size_t size);
MessageStatus GetStatus(Message* message);
void SetStatus(Message* message, MessageStatus status);
size_t GetOffset(Message* message);

size_t SizeOfMessageStruct();

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

#endif /* WIDEVINE_ODK_SRC_SERIALIZATION_BASE_H_ */