/*
 * Copyright (C) 2012-2015 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.
 *
*/
#ifdef _WIN32
  // Ensure that Winsock2.h is included before Windows.h, which can get
  // pulled in by anybody (e.g., Boost).
  #include <Winsock2.h>
#endif

#include <boost/bind.hpp>
#include <sstream>

#include "gazebo/physics/World.hh"

#include "gazebo/common/Events.hh"
#include "gazebo/common/Exception.hh"

#include "gazebo/transport/transport.hh"

#include "gazebo/rendering/DepthCamera.hh"
#include "gazebo/rendering/Scene.hh"
#include "gazebo/rendering/RenderingIface.hh"
#include "gazebo/rendering/RenderEngine.hh"

#include "gazebo/sensors/SensorFactory.hh"
#include "gazebo/sensors/DepthCameraSensor.hh"
#include "gazebo/sensors/Noise.hh"

using namespace gazebo;
using namespace sensors;

// TODO:
// 1) Handle new image formats (override getImageFormat) in DepthCamera.cc
// 2) Return correct depths for the sensor (override getImageDepth) in DepthCamera.cc
// 3) New saveFrame function that saves the correct depth data - look at saveframebuffer stuff that camera.cc has

GZ_REGISTER_STATIC_SENSOR("depth", DepthCameraSensor)

//////////////////////////////////////////////////
DepthCameraSensor::DepthCameraSensor()
    : Sensor(sensors::IMAGE)
{
  this->rendered = false;
  this->connections.push_back(
      event::Events::ConnectRender(
        boost::bind(&DepthCameraSensor::Render, this)));
}

//////////////////////////////////////////////////
DepthCameraSensor::~DepthCameraSensor()
{
}

//////////////////////////////////////////////////
void DepthCameraSensor::Load(const std::string &_worldName,
                                   sdf::ElementPtr _sdf)
{
  Sensor::Load(_worldName, _sdf);
}

//////////////////////////////////////////////////
std::string DepthCameraSensor::GetTopic() const
{
  std::string topicName = "~/";
  topicName += this->parentName + "/" + this->GetName() + "/image";
  boost::replace_all(topicName, "::", "/");

  return topicName;
}

//////////////////////////////////////////////////
void DepthCameraSensor::Load(const std::string &_worldName)
{
  Sensor::Load(_worldName);
  this->imagePub = this->node->Advertise<msgs::ImageStamped>(
      this->GetTopic(), 50);
}

//////////////////////////////////////////////////
void DepthCameraSensor::Init()
{
  if (rendering::RenderEngine::Instance()->GetRenderPathType() ==
      rendering::RenderEngine::NONE)
  {
    gzerr << "Unable to create DepthCameraSensor. Rendering is disabled.\n";
    return;
  }

  std::string worldName = this->world->GetName();

  if (!worldName.empty())
  {
    this->scene = rendering::get_scene(worldName);
    if (!this->scene)
    {
      this->scene = rendering::create_scene(worldName, false, true);

      // This usually means rendering is not available
      if (!this->scene)
      {
        gzerr << "Unable to create DepthCameraSensor.\n";
        return;
      }
    }

    this->camera = this->scene->CreateDepthCamera(
        this->sdf->Get<std::string>("name"), false);

    if (!this->camera)
    {
      gzerr << "Unable to create depth camera sensor\n";
      return;
    }
    this->camera->SetCaptureData(true);

    sdf::ElementPtr cameraSdf = this->sdf->GetElement("camera");
    this->camera->Load(cameraSdf);

    // Do some sanity checks
    if (this->camera->GetImageWidth() == 0 ||
        this->camera->GetImageHeight() == 0)
    {
      gzthrow("image has zero size");
    }

    this->camera->Init();
    this->camera->CreateRenderTexture(this->GetName() + "_RttTex_Image");
    this->camera->CreateDepthTexture(this->GetName() + "_RttTex_Depth");
    ignition::math::Pose3d cameraPose = this->pose;
    if (cameraSdf->HasElement("pose"))
      cameraPose = cameraSdf->Get<ignition::math::Pose3d>("pose") + cameraPose;

    this->camera->SetWorldPose(cameraPose);
    this->camera->AttachToVisual(this->parentId, true);

    if (cameraSdf->HasElement("noise"))
    {
      this->noises[CAMERA_NOISE] =
        NoiseFactory::NewNoiseModel(cameraSdf->GetElement("noise"),
        this->GetType());
      this->noises[CAMERA_NOISE]->SetCamera(this->camera);
    }
  }
  else
    gzerr << "No world name\n";

  // Disable clouds and moon on server side until fixed and also to improve
  // performance
  this->scene->SetSkyXMode(rendering::Scene::GZ_SKYX_ALL &
      ~rendering::Scene::GZ_SKYX_CLOUDS &
      ~rendering::Scene::GZ_SKYX_MOON);

  Sensor::Init();
}

//////////////////////////////////////////////////
void DepthCameraSensor::Fini()
{
  this->imagePub.reset();
  Sensor::Fini();

  if (this->camera)
  {
    this->scene->RemoveCamera(this->camera->GetName());
  }

  this->camera.reset();
  this->scene.reset();
}

//////////////////////////////////////////////////
void DepthCameraSensor::SetActive(bool value)
{
  Sensor::SetActive(value);
}

//////////////////////////////////////////////////
void DepthCameraSensor::Render()
{
  if (!this->camera || !this->IsActive() || !this->NeedsUpdate())
    return;

  this->camera->Render();

  this->rendered = true;
  this->lastMeasurementTime = this->scene->GetSimTime();
}

//////////////////////////////////////////////////
bool DepthCameraSensor::UpdateImpl(bool /*_force*/)
{
  // Sensor::Update(force);
  if (!this->rendered)
    return false;

  this->camera->PostRender();

  // TODO: Is this correct??
  if (this->imagePub && this->imagePub->HasConnections())
  {
    msgs::ImageStamped msg;
    msgs::Set(msg.mutable_time(), this->scene->GetSimTime());
    msg.mutable_image()->set_width(this->camera->GetImageWidth());
    msg.mutable_image()->set_height(this->camera->GetImageHeight());
    msg.mutable_image()->set_pixel_format(gazebo::common::Image::PixelFormat::R_FLOAT32); // Depth format - Float (from Carlos Aguero)

    msg.mutable_image()->set_step(this->camera->GetImageWidth() * 4); // ImageDepth = 4 bytes (float)
    msg.mutable_image()->set_data(this->camera->GetDepthData(),
        msg.image().width() * 4 *
        msg.image().height()); // NOTE: We need to get the depth data, not image data! ImageDepth = 4 bytes (float)

    this->imagePub->Publish(msg);
  }

  this->rendered = false;
  return true;
}

//////////////////////////////////////////////////
unsigned int DepthCameraSensor::GetImageWidth() const
{
  if (this->camera)
    return this->camera->GetImageWidth();
  return 0;
}

//////////////////////////////////////////////////
unsigned int DepthCameraSensor::GetImageHeight() const
{
  if (this->camera)
    return this->camera->GetImageHeight();
  return 0;
}

//////////////////////////////////////////////////
const float *DepthCameraSensor::GetDepthData()
{
  return this->camera->GetDepthData();
}

//////////////////////////////////////////////////
// TODO: SaveFrame reverts to the RGB camera's saveFrame function which takes an unsigned char array
// and limited image formats (R_FLOAT32 not included) and tries to save it.
// We need to write a separate one for DepthCamera
bool DepthCameraSensor::SaveFrame(const std::string &_filename)
{
  this->SetActive(true);
  return this->camera->SaveFrame(_filename);
}

//////////////////////////////////////////////////
bool DepthCameraSensor::IsActive()
{
  return Sensor::IsActive() ||
    (this->imagePub && this->imagePub->HasConnections());
}