/*
 * Copyright (C) 2012 Open Source Robotics Foundation
 *
 * 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.
 *
*/
#ifndef GAZEBO_MSGS_MSGS_HH_
#define GAZEBO_MSGS_MSGS_HH_

#include <string>

#include <sdf/sdf.hh>

#include <ignition/math/Inertial.hh>
#include <ignition/math/MassMatrix3.hh>
#include <ignition/math/Plane.hh>
#include <ignition/math/Pose3.hh>
#include <ignition/math/Vector3.hh>

#include "gazebo/math/Quaternion.hh"

#include "gazebo/msgs/MessageTypes.hh"

// Remove gazebo/math includes in Gazebo8
// Adding the word deprecation so that a grep will find this.
#include "gazebo/math/MathTypes.hh"
#include "gazebo/math/Vector3.hh"
#include "gazebo/math/Pose.hh"
#include "gazebo/math/Plane.hh"

#include "gazebo/common/SphericalCoordinates.hh"
#include "gazebo/common/Color.hh"
#include "gazebo/common/Time.hh"
#include "gazebo/common/Image.hh"

namespace gazebo
{
  /// \ingroup gazebo_msgs Messages
  /// \brief Messages namespace
  namespace msgs
  {
    /// \addtogroup gazebo_msgs Messages
    /// \brief All messages and helper functions
    /// \{

    /// \brief Create a request message
    /// \param[in] _request Request string
    /// \param[in] _data Optional data string
    /// \return A Request message
    GAZEBO_VISIBLE
    msgs::Request *CreateRequest(const std::string &_request,
                                 const std::string &_data = "");

    /// \brief Initialize a message
    /// \param[in] _message Message to initialize
    /// \param[in] _id Optional string id
    GAZEBO_VISIBLE
    void Init(google::protobuf::Message &_message, const std::string &_id ="");

    /// \brief Time stamp a header
    /// \param[in] _header Header to stamp
    GAZEBO_VISIBLE
    void Stamp(msgs::Header *_header);

    /// \brief Set the time in a time message
    /// \param[in] _time A Time message
    GAZEBO_VISIBLE
    void Stamp(msgs::Time *_time);

    /// \cond
    GAZEBO_VISIBLE
    std::string Package(const std::string &type,
        const google::protobuf::Message &message);
    /// \endcond

    /// \brief Convert a double to a msgs::Any
    /// \param[in] _v The double to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const double _v);

    /// \brief Convert an int to a msgs::Any
    /// \param[in] _i The int to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const int _i);

    /// \brief Convert a std::string to a msgs::Any
    /// \param[in] _s The string to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const std::string &_s);

    /// \brief Convert a string literal to a msgs::Any
    /// \param[in] _s The string to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const char *_s);

    /// \brief Convert a bool to a msgs::Any
    /// \param[in] _b The bool to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const bool _b);

    /// \brief Convert an ignition::math::Vector3d to a msgs::Any
    /// \param[in] _v The vector to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const ignition::math::Vector3d &_v);

    /// \brief Convert a common::Color to a msgs::Any
    /// \param[in] _c The color to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const common::Color &_c);

    /// \brief Convert an ignition::math::Pose3d to a msgs::Any
    /// \param[in] _p The pose to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const ignition::math::Pose3d &_p);

    /// \brief Convert an ignition::math::Quaternion to a msgs::Any
    /// \param[in] _q The quaternion to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const ignition::math::Quaterniond &_q);

    /// \brief Convert a common::Time to a msgs::Any
    /// \param[in] _t The time to convert.
    /// \return A msgs::Any object.
    GAZEBO_VISIBLE
    msgs::Any ConvertAny(const common::Time &_t);

    /// \brief Convert a ignition::math::Vector3 to a msgs::Vector3d
    /// \param[in] _v The vector to convert
    /// \return A msgs::Vector3d object
    GAZEBO_VISIBLE
    msgs::Vector3d Convert(const ignition::math::Vector3d &_v);

    /// \brief Convert a ignition::math::Vector2d to a msgs::Vector2d
    /// \param[in] _v The vector to convert
    /// \return A msgs::Vector2d object
    GAZEBO_VISIBLE
    msgs::Vector2d Convert(const ignition::math::Vector2d &_v);

    /// \brief Convert a ignition::math::Quaternion to a msgs::Quaternion
    /// \param[in] _q The quaternion to convert
    /// \return A msgs::Quaternion object
    GAZEBO_VISIBLE
    msgs::Quaternion Convert(const ignition::math::Quaterniond &_q);

    /// \brief Convert a ignition::math::Pose to a msgs::Pose
    /// \param[in] _p The pose to convert
    /// \return A msgs::Pose object
    GAZEBO_VISIBLE
    msgs::Pose Convert(const ignition::math::Pose3d &_p);

    /// \brief Convert a common::Color to a msgs::Color
    /// \param[in] _c The color to convert
    /// \return A msgs::Color object
    GAZEBO_VISIBLE
    msgs::Color Convert(const common::Color &_c);

    /// \brief Convert a common::Time to a msgs::Time
    /// \param[in] _t The time to convert
    /// \return A msgs::Time object
    GAZEBO_VISIBLE
    msgs::Time Convert(const common::Time &_t);

    /// \brief Convert an ignition::math::Inertiald to a msgs::Inertial
    /// \param[in] _i The Inertiald to convert
    /// \return A msgs::Inertial object
    GAZEBO_VISIBLE
    msgs::Inertial Convert(const ignition::math::Inertiald &_i);

    /// \brief Convert an ignition::math::MassMatrix3d to a msgs::Inertial
    /// \param[in] _m The MassMatrix3d to convert
    /// \return A msgs::Inertial object
    GAZEBO_VISIBLE
    msgs::Inertial Convert(const ignition::math::MassMatrix3d &_m);

    /// \brief Convert a ignition::math::Planed to a msgs::PlaneGeom
    /// \param[in] _p The plane to convert
    /// \return A msgs::PlaneGeom object
    GAZEBO_VISIBLE
    msgs::PlaneGeom Convert(const ignition::math::Planed &_p);

    /// \brief Convert a string to a msgs::Joint::Type enum.
    /// \param[in] _str Joint type string.
    /// \return A msgs::Joint::Type enum. Defaults to REVOLUTE
    /// if _str is unrecognized.
    GAZEBO_VISIBLE
    msgs::Joint::Type ConvertJointType(const std::string &_str);

    /// \brief Convert a msgs::Joint::Type to a string.
    /// \param[in] _type A msgs::Joint::Type enum.
    /// \return Joint type string. Returns "unknown" if
    /// _type is unrecognized.
    GAZEBO_VISIBLE
    std::string ConvertJointType(const msgs::Joint::Type &_type);

    /// \brief Convert a string to a msgs::Geometry::Type enum.
    /// \param[in] _str Geometry type string.
    /// \return A msgs::Geometry::Type enum.
    GAZEBO_VISIBLE
    msgs::Geometry::Type ConvertGeometryType(const std::string &_str);

    /// \brief Convert a msgs::Geometry::Type to a string.
    /// \param[in] _type A msgs::Geometry::Type enum.
    /// \return Geometry type string.
    GAZEBO_VISIBLE
    std::string ConvertGeometryType(const msgs::Geometry::Type _type);

    /// \brief Convert a msgs::Vector3d to an ignition::math::Vector
    /// \param[in] _v The plane to convert
    /// \return An ignition::math::Vector3 object
    GAZEBO_VISIBLE
    ignition::math::Vector3d ConvertIgn(const msgs::Vector3d &_v);

    /// \brief Convert a msgs::Vector2d to an ignition::math::Vector2d
    /// \param[in] _v The vector2 to convert
    /// \return An ignition::math::Vector2d object
    GAZEBO_VISIBLE
    ignition::math::Vector2d ConvertIgn(const msgs::Vector2d &_v);

    /// \brief Convert a msgs::Quaternion to an ignition::math::Quaternion
    /// \param[in] _q The quaternion to convert
    /// \return An ignition::math::Quaternion object
    GAZEBO_VISIBLE
    ignition::math::Quaterniond ConvertIgn(const msgs::Quaternion &_q);

    /// \brief Convert a msgs::Pose to an ignition::math::Pose
    /// \param[in] _p The pose to convert
    /// \return An ignition::math::Pose object
    GAZEBO_VISIBLE
    ignition::math::Pose3d ConvertIgn(const msgs::Pose &_p);

    /// \brief Convert a msgs::Inertial to an ignition::math::Inertiald
    /// \param[in] _i The inertial to convert
    /// \return An ignition::math::Inertiald object
    GAZEBO_VISIBLE
    ignition::math::Inertiald Convert(const msgs::Inertial &_i);

    /// \brief Convert a msgs::Image to a common::Image
    /// \param[out] _img The common::Image container
    /// \param[in] _msg The Image message to convert
    GAZEBO_VISIBLE
    void Set(common::Image &_img, const msgs::Image &_msg);

    /// \brief Convert a msgs::Color to a common::Color
    /// \param[in] _c The color to convert
    /// \return A common::Color object
    GAZEBO_VISIBLE
    common::Color Convert(const msgs::Color &_c);

    /// \brief Convert a msgs::Time to a common::Time
    /// \param[in] _t The time to convert
    /// \return A common::Time object
    GAZEBO_VISIBLE
    common::Time Convert(const msgs::Time &_t);

    /// \brief Convert a msgs::PlaneGeom to an ignition::math::Planed
    /// \param[in] _p The plane to convert
    /// \return An ignition::math::Planed object
    GAZEBO_VISIBLE
    ignition::math::Planed ConvertIgn(const msgs::PlaneGeom &_p);

    /// \brief Set a msgs::Image from a common::Image
    /// \param[out] _msg A msgs::Image pointer
    /// \param[in] _i A common::Image reference
    GAZEBO_VISIBLE
    void Set(msgs::Image *_msg, const common::Image &_i);

    /// \brief Set a msgs::Vector3d from an ignition::math::Vector3d
    /// \param[out] _pt A msgs::Vector3d pointer
    /// \param[in] _v An ignition::math::Vector3d reference
    GAZEBO_VISIBLE
    void Set(msgs::Vector3d *_pt, const ignition::math::Vector3d &_v);

    /// \brief Set a msgs::Vector2d from an ignition::math::Vector2d
    /// \param[out] _pt A msgs::Vector2d pointer
    /// \param[in] _v An ignition::math::Vector2d reference
    GAZEBO_VISIBLE
    void Set(msgs::Vector2d *_pt, const ignition::math::Vector2d &_v);

    /// \brief Set a msgs::Quaternion from an ignition::math::Quaterniond
    /// \param[out] _q A msgs::Quaternion pointer
    /// \param[in] _v An ignition::math::Quaterniond reference
    GAZEBO_VISIBLE
    void Set(msgs::Quaternion *_q, const ignition::math::Quaterniond &_v);

    /// \brief Set a msgs::Pose from an ignition::math::Pose3d
    /// \param[out] _p A msgs::Pose pointer
    /// \param[in] _v An ignition::math::Pose3d reference
    GAZEBO_VISIBLE
    void Set(msgs::Pose *_p, const ignition::math::Pose3d &_v);

    /// \brief Set a msgs::Color from a common::Color
    /// \param[out] _p A msgs::Color pointer
    /// \param[in] _v A common::Color reference
    GAZEBO_VISIBLE
    void Set(msgs::Color *_c, const common::Color &_v);

    /// \brief Set a msgs::Time from a common::Time
    /// \param[out] _p A msgs::Time pointer
    /// \param[in] _v A common::Time reference
    GAZEBO_VISIBLE
    void Set(msgs::Time *_t, const common::Time &_v);

    /// \brief Set a msgs::SphericalCoordinates from
    /// a common::SphericalCoordinates object.
    /// \param[out] _p A msgs::SphericalCoordinates pointer.
    /// \param[in] _v A common::SphericalCoordinates reference
    GAZEBO_VISIBLE
    void Set(msgs::SphericalCoordinates *_s,
             const common::SphericalCoordinates &_v);

    /// \brief Set a msgs::Inertial from an ignition::math::Inertiald
    /// \param[out] _i A msgs::Inertial pointer
    /// \param[in] _m An ignition::math::Inertiald reference
    GAZEBO_VISIBLE
    void Set(msgs::Inertial *_i, const ignition::math::Inertiald &_m);

    /// \brief Set a msgs::Inertial from an ignition::math::MassMatrix3d
    /// \param[out] _i A msgs::Inertial pointer
    /// \param[in] _m An ignition::math::MassMatrix3d reference
    GAZEBO_VISIBLE
    void Set(msgs::Inertial *_i, const ignition::math::MassMatrix3d &_m);

    /// \brief Set a msgs::Plane from an ignition::math::Planed
    /// \param[out] _p A msgs::Plane pointer
    /// \param[in] _v An ignition::math::Planed reference
    GAZEBO_VISIBLE
    void Set(msgs::PlaneGeom *_p, const ignition::math::Planed &_v);

    /// \brief Create a msgs::TrackVisual from a track visual SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::TrackVisual object
    GAZEBO_VISIBLE
    msgs::TrackVisual TrackVisualFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::GUI from a GUI SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::GUI object
    GAZEBO_VISIBLE
    msgs::GUI GUIFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Light from a light SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Light object
    GAZEBO_VISIBLE
    msgs::Light LightFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::MeshGeom from a mesh SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::MeshGeom object
    GAZEBO_VISIBLE
    msgs::MeshGeom MeshFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Geometry from a geometry SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Geometry object
    GAZEBO_VISIBLE
    msgs::Geometry GeometryFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Visual from a visual SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Visual object
    GAZEBO_VISIBLE
    msgs::Visual VisualFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Collision from a collision SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Collision object
    GAZEBO_VISIBLE
    msgs::Collision CollisionFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Surface from a surface SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Surface object
    GAZEBO_VISIBLE
    msgs::Surface SurfaceFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Friction from a friction SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Friction object
    GAZEBO_VISIBLE
    msgs::Friction FrictionFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Axis from an axis SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Axis object
    GAZEBO_VISIBLE
    msgs::Axis AxisFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Joint from a joint SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Joint object
    GAZEBO_VISIBLE
    msgs::Joint JointFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Plugin from a plugin SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Plugin object
    GAZEBO_VISIBLE
    msgs::Plugin PluginFromSDF(const sdf::ElementPtr _sdf);

    /// \brief Create or update an SDF element from a msgs::Visual
    /// \param[in] _msg Visual messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr VisualToSDF(const msgs::Visual &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Material
    /// If _sdf is supplied and _msg has script uri's
    /// the <uri> elements will be removed from _sdf.
    /// \param[in] _msg Material messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr MaterialToSDF(const msgs::Material &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Convert a string to a msgs::Material::ShaderType enum.
    /// \param[in] _str Shader type string.
    /// \return A msgs::Material::ShaderType enum. Defaults to VERTEX
    /// if _str is unrecognized.
    GAZEBO_VISIBLE
    msgs::Material::ShaderType ConvertShaderType(const std::string &_str);

    /// \brief Convert a msgs::ShaderType to a string.
    /// \param[in] _type A msgs::ShaderType enum.
    /// \return Shader type string. Returns "unknown" if
    /// _type is unrecognized.
    GAZEBO_VISIBLE
    std::string ConvertShaderType(const msgs::Material::ShaderType &_type);

    /// \brief Create a msgs::Fog from a fog SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Fog object
    GAZEBO_VISIBLE
    msgs::Fog FogFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Scene from a scene SDF element
    /// \param[in] _sdf The sdf element
    /// \return The new msgs::Scene object
    GAZEBO_VISIBLE
    msgs::Scene SceneFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::Sensor from a sensor SDF element
    /// \param[in] _sdf The sensor sdf element
    /// \return The new msgs::Sensor object
    /// \sa CameraSensorFromSDF
    /// \sa RaySensorFromSDF
    /// \sa ContactSensorFromSDF
    GAZEBO_VISIBLE
    msgs::Sensor SensorFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::CameraSensor from a camera sensor SDF element
    /// \param[in] _sdf The camera sensor sdf element
    /// \return The new msgs::CameraSensor object
    /// \sa SensorFromSDF
    GAZEBO_VISIBLE
    msgs::CameraSensor CameraSensorFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::RaySensor from a ray sensor SDF element
    /// \param[in] _sdf The ray sensor sdf element
    /// \return The new msgs::RaySensor object
    /// \sa SensorFromSDF
    GAZEBO_VISIBLE
    msgs::RaySensor RaySensorFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create a msgs::ContactSensor from a contact sensor SDF element
    /// \param[in] _sdf The contact sensor sdf element
    /// \return The new msgs::ContactSensor object
    /// \sa SensorFromSDF
    GAZEBO_VISIBLE
    msgs::ContactSensor ContactSensorFromSDF(sdf::ElementPtr _sdf);

    /// \brief Create or update an SDF element from a msgs::Light
    /// \param[in] _msg Light messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr LightToSDF(const msgs::Light &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::CameraSensor
    /// \param[in] _msg CameraSensor messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr CameraSensorToSDF(const msgs::CameraSensor &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Plugin
    /// \param[in] _msg Plugin messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr PluginToSDF(const msgs::Plugin &_plugin,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Collision
    /// \param[in] _msg Collision messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr CollisionToSDF(const msgs::Collision &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Link.
    /// If _sdf is supplied and _msg has any collisions or visuals,
    /// the <collision> and <visual> elements will be removed from _sdf.
    /// \param[in] _msg Link messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr LinkToSDF(const msgs::Link &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Inertial
    /// \param[in] _msg Inertial messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr InertialToSDF(const msgs::Inertial &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Surface
    /// \param[in] _msg Surface messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr SurfaceToSDF(const msgs::Surface &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Geometry
    /// If _sdf is supplied and the _msg has non-empty repeated elements,
    /// any existing sdf elements will be removed from _sdf prior to adding
    /// the new elements from _msg.
    /// \param[in] _msg Geometry messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr GeometryToSDF(const msgs::Geometry &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from a msgs::Mesh
    /// \param[in] _msg Mesh messsage
    /// \param[in] _sdf if supplied, performs an update from _msg instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr MeshToSDF(const msgs::MeshGeom &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Add a simple box link to a Model message.
    /// The size and mass of the box are specified, and a
    /// single collision is added, along with an inertial
    /// block corresponding to a box of uniform density.
    /// \param[out] _model The msgs::Model to which the link is added.
    /// \param[in] _mass Mass of the box.
    /// \param[in] _size Size of the box.
    GAZEBO_VISIBLE
    void AddBoxLink(msgs::Model &_model, const double _mass,
                    const ignition::math::Vector3d &_size);

    /// \brief Add a simple cylinder link to a Model message.
    /// The radius, length, and mass of the cylinder are specified, and a
    /// single collision is added, along with an inertial
    /// block corresponding to a cylinder of uniform density
    /// with an axis of symmetry along the Z axis.
    /// \param[out] _model The msgs::Model to which the link is added.
    /// \param[in] _mass Mass of the cylinder.
    /// \param[in] _radius Radius of the cylinder.
    /// \param[in] _length Length of the cylinder.
    GAZEBO_VISIBLE
    void AddCylinderLink(msgs::Model &_model, const double _mass,
                         const double _radius, const double _length);

    /// \brief Add a simple sphere link to a Model message.
    /// The size and mass of the sphere are specified, and a
    /// single collision is added, along with an inertial
    /// block corresponding to a sphere of uniform density.
    /// \param[out] _model The msgs::Model to which the link is added.
    /// \param[in] _mass Mass of the sphere.
    /// \param[in] _radius Radius of the sphere.
    GAZEBO_VISIBLE
    void AddSphereLink(msgs::Model &_model, const double _mass,
                    const double _radius);

    /// \brief Add a link with a collision and visual
    /// of specified geometry to a model message.
    /// It does not set any inertial values.
    /// \param[out] _model The msgs::Model object to receive a new link.
    /// \param[in] _geom Geometry to be added to collision and visual.
    GAZEBO_VISIBLE
    void AddLinkGeom(Model &_msg, const Geometry &_geom);

    /// \brief Create or update an SDF element from msgs::Model.
    /// If _sdf is supplied and _msg has any links or joints,
    /// the <link> and <joint> elements will be removed from _sdf.
    /// \param[in] _msg The msgs::Model object.
    /// \param[in] _sdf if supplied, performs an update from _sdf instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr ModelToSDF(const msgs::Model &_msg,
        sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \brief Create or update an SDF element from msgs::Joint.
    /// \param[in] _msg The msgs::Joint object.
    /// \param[in] _sdf if supplied, performs an update from _sdf instead of
    /// creating a new sdf element.
    /// \return The new SDF element.
    GAZEBO_VISIBLE
    sdf::ElementPtr JointToSDF(const msgs::Joint &_msg,
                      sdf::ElementPtr _sdf = sdf::ElementPtr());

    /// \cond
    GAZEBO_VISIBLE
    const google::protobuf::FieldDescriptor *GetFD(
        google::protobuf::Message &message, const std::string &name);
    /// \endcond

    /// \brief Get the header from a protobuf message
    /// \param[in] _message A google protobuf message
    /// \return A pointer to the message's header
    GAZEBO_VISIBLE
    msgs::Header *GetHeader(google::protobuf::Message &_message);

    /// \}
  }
}

#endif
