
// this is for emacs file handling -*- mode: c++; indent-tabs-mode: nil -*-

// -- BEGIN LICENSE BLOCK ----------------------------------------------
// Copyright 2019 FZI Forschungszentrum Informatik
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
// -- END LICENSE BLOCK ------------------------------------------------

//----------------------------------------------------------------------
/*!\file
 *
 * \author  Lea Steffen steffen@fzi.de
 * \date    2019-04-01
 *
 */
//----------------------------------------------------------------------

#ifndef UR_RTDE_DRIVER_RTDE__HEADER_H_INCLUDED
#define UR_RTDE_DRIVER_RTDE__HEADER_H_INCLUDED

#include <cstddef>
#include <endian.h>
#include "ur_rtde_driver/types.h"
#include "ur_rtde_driver/comm/package_serializer.h"

namespace ur_driver
{
namespace rtde_interface
{
/*!
 * \brief Possible package types
 */
enum class PackageType : uint8_t
{
  RTDE_REQUEST_PROTOCOL_VERSION = 86,       // ascii V
  RTDE_GET_URCONTROL_VERSION = 118,         // ascii v
  RTDE_TEXT_MESSAGE = 77,                   // ascii M
  RTDE_DATA_PACKAGE = 85,                   // ascii U
  RTDE_CONTROL_PACKAGE_SETUP_OUTPUTS = 79,  // ascii O
  RTDE_CONTROL_PACKAGE_SETUP_INPUTS = 73,   // ascii I
  RTDE_CONTROL_PACKAGE_START = 83,          // ascii S
  RTDE_CONTROL_PACKAGE_PAUSE = 80           // ascii P
};

/*!
 * \brief This class represents the header for RTDE packages.
 */
class PackageHeader
{
public:
  PackageHeader() = default;
  virtual ~PackageHeader() = default;
  using _package_size_type = uint16_t;

  /*!
   * \brief Reads a buffer, interpreting the next bytes as the size of the contained package.
   *
   * \param buf The given byte stream containing a serialized package
   *
   * \returns The size of the given serialized package
   */
  static size_t getPackageLength(uint8_t* buf)
  {
    return be16toh(*(reinterpret_cast<_package_size_type*>(buf)));
  }

  /*!
   * \brief Creates a serialization of a header based on given values.
   *
   * \param buffer The buffer to write the serialization to
   * \param package_type The type of the package
   * \param payload_length The length of the package's payload
   *
   * \returns
   */
  static size_t serializeHeader(uint8_t* buffer, PackageType package_type, uint16_t payload_length)
  {
    uint16_t header_size = sizeof(_package_size_type) + sizeof(PackageType);
    uint16_t size = header_size + payload_length;
    comm::PackageSerializer::serialize(buffer, size);
    comm::PackageSerializer::serialize(buffer + sizeof(size), package_type);
    return header_size;
  }
};

}  // namespace rtde_interface
}  // namespace ur_driver

#endif  // #ifndef UR_RTDE_DRIVER_RTDE__HEADER_H_INCLUDED
