/*
 * Copyright (C) 2018 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 GZ_RENDERING_OGRE2_OGRE2RENDERTARGET_HH_
#define GZ_RENDERING_OGRE2_OGRE2RENDERTARGET_HH_

#include <string>
#include <vector>
#include <gz/math/Color.hh>

#include "gz/rendering/base/BaseRenderTypes.hh"
#include "gz/rendering/base/BaseRenderTarget.hh"
#include "gz/rendering/ogre2/Ogre2Includes.hh"
#include "gz/rendering/ogre2/Ogre2Object.hh"
#include "gz/rendering/ogre2/Ogre2RenderTargetMaterial.hh"

namespace Ogre
{
  class Camera;
  class RenderTarget;
  class Texture;
}

namespace ignition
{
  namespace rendering
  {
    inline namespace IGNITION_RENDERING_VERSION_NAMESPACE {
    //
    /// \brief Ogre2.x implementation of the render target class
    class IGNITION_RENDERING_OGRE2_VISIBLE Ogre2RenderTarget :
      public virtual BaseRenderTarget<Ogre2Object>
    {
      /// \brief Constructor
      protected: Ogre2RenderTarget();

      /// \brief Destructor
      public: virtual ~Ogre2RenderTarget();

      /// \brief Get the anti-aliasing level
      public: virtual unsigned int AntiAliasing() const;

      /// \brief set the anti-aliasing level
      /// \param[in] _aa Anti-aliasing level
      public: virtual void SetAntiAliasing(unsigned int _aa);

      /// \brief Copy the render target buffer data to an image
      /// \param[in] _image Image to copy the data to
      public: virtual void Copy(Image &_image) const override;

      /// \brief Get a pointer to the internal ogre camera
      /// \return Pointer to ogre camera
      public: virtual Ogre::Camera *Camera() const;

      /// \brief Set the ogre camera to use for this render target
      /// \param[in] _camera Pointer to ogre camera
      public: virtual void SetCamera(Ogre::Camera *_camera);

      // Documentation inherited
      public: virtual math::Color BackgroundColor() const override;

      /// \brief Set the background color of the render target
      /// \param[in] _color Color to set the background to
      public: virtual void SetBackgroundColor(math::Color _color);

      // Documentation inherited
      public: virtual void PreRender() override;

      // Documentation inherited
      public: virtual void PostRender() override;

      /// \brief Main render call
      public: virtual void Render();

      /// \brief Destroy the render target
      public: virtual void Destroy() override = 0;

      /// \brief Set a material to render on every object. This method is used
      /// for special cases like the render target of a depth camera.
      /// \param[in] _material The material to render
      public: void SetMaterial(MaterialPtr _material);

      /// \brief Get a pointer to the ogre render target
      public: virtual Ogre::RenderTarget *RenderTarget() const = 0;

      /// \brief Update the render pass chain
      public: static void UpdateRenderPassChain(
          Ogre::CompositorWorkspace *_workspace,
          const std::string &_workspaceDefName,
          const std::string &_baseNode, const std::string &_finalNode,
          const std::vector<RenderPassPtr> &_renderPasses, bool _recreateNodes);

      /// \brief Update the background color
      protected: virtual void UpdateBackgroundColor();

      /// \brief Update the render pass chain
      protected: virtual void UpdateRenderPassChain();

      /// \brief Create a compositor shadow node with the same number of shadow
      /// textures as the number of shadow casting lights
      protected: void UpdateShadowNode();

      /// \brief Implementation of the Rebuild function
      protected: virtual void RebuildImpl() override;

      /// \brief Rebuild the render target
      protected: virtual void RebuildTarget() = 0;

      /// \brief Rebuild the compositor
      protected: virtual void RebuildCompositor();

      /// \brief Build the comopsitor
      protected: virtual void BuildCompositor();

      /// \brief Destroy the compositor
      protected: virtual void DestroyCompositor();

      /// \brief Re-initializes render target material to apply a material to
      /// everything in the scene. Does nothing if no material has been set
      /// \sa Ogre2RenderTarget::RebuildImpl()
      /// \sa BaseRenderTarget::Rebuild()
      protected: void RebuildMaterial();

      /// \brief Create ogre compositor shadow node definition. The function
      /// takes a vector of parameters that describe the type, number, and
      /// resolution of textures create. Note that it is not necessary to
      /// create separate textures for each shadow map. It is more efficient to
      /// define a large texture atlas which is composed of multiple shadow
      /// maps each occupying a subspace within the texture. This function is
      /// similar to Ogre::ShadowNodeHelper::createShadowNodeWithSettings but
      /// fixes a problem with the shadow map index when directional and spot
      /// light shadow textures are defined on two different texture atlases.
      /// \param[in] _compositorManager ogre compositor manager
      /// \param[in] _shadowNodeName Name of the shadow node definition
      /// \param[in] _shadowParams Parameters containing the shadow type,
      /// texure resolution and position on the texture atlas.
      private: void CreateShadowNodeWithSettings(
          Ogre::CompositorManager2 *_compositorManager,
          const std::string &_shadowNodeName,
          const Ogre::ShadowNodeHelper::ShadowParamVec &_shadowParams);

      /// \brief Pointer to the internal ogre camera
      protected: Ogre::Camera *ogreCamera = nullptr;

      /// \brief Ogre's compositor workspace - the main interface to render
      /// into a render target or render texture.
      protected: Ogre::CompositorWorkspace *ogreCompositorWorkspace = nullptr;

      /// \brief Ogre's compositor workspace definition name
      protected: std::string ogreCompositorWorkspaceDefName;

      /// \brief Stores the background color of the render target
      protected: Ogre::ColourValue ogreBackgroundColor;

      /// \brief a material used by for the render target
      protected: MaterialPtr material;

      /// \brief Helper class that applies the material to the render target
      protected: Ogre2RenderTargetMaterialPtr materialApplicator;

      /// \brief Flag to indicate if the render target color has changed
      protected: bool colorDirty = true;

      /// \brief Anti-aliasing level
      protected: unsigned int antiAliasing = 4;
    };

    /// \brief Ogre2.x implementation of the render texture class
    class IGNITION_RENDERING_OGRE2_VISIBLE Ogre2RenderTexture :
      public virtual BaseRenderTexture<Ogre2RenderTarget>
    {
      /// \brief Constructor
      protected: Ogre2RenderTexture();

      /// \brief Destructor
      public: virtual ~Ogre2RenderTexture();

      // Documentation inherited.
      public: virtual void Destroy() override;

      // Documentation inherited
      public: virtual void PreRender() override;

      // Documentation inherited
      public: virtual void PostRender() override;

      // Documentation inherited
      public: virtual unsigned int GLId() const override;

      // Documentation inherited.
      public: virtual Ogre::RenderTarget *RenderTarget() const override;

      // Documentation inherited.
      protected: virtual void RebuildTarget() override;

      /// \brief Destroy the render texture
      protected: virtual void DestroyTarget();

      /// \brief Build the render texture
      protected: virtual void BuildTarget();

      /// \brief Pointer to the internal ogre render texture object
      protected: Ogre::Texture *ogreTexture = nullptr;

      /// \brief Make scene our friend so it can create a ogre2 render texture
      private: friend class Ogre2Scene;
    };

    /// \brief Ogre2.x implementation of the render window class
    class IGNITION_RENDERING_OGRE2_VISIBLE Ogre2RenderWindow :
      public virtual BaseRenderWindow<Ogre2RenderTarget>
    {
      /// \brief Constructor
      protected: Ogre2RenderWindow();

      /// \brief Destructor
      public: virtual ~Ogre2RenderWindow();

      // Documentation inherited.
      public: virtual void Destroy() override;

      // Documentation inherited.
      public: virtual Ogre::RenderTarget *RenderTarget() const override;

      // Documentation inherited.
      protected: virtual void RebuildTarget() override;

      /// \brief Build the render window
      protected: virtual void BuildTarget();

      /// \brief Pointer to the internal ogre render target object
      protected: Ogre::RenderTarget *ogreRenderWindow = nullptr;

      /// \brief Make scene our friend so it can create a ogre2 render window
      private: friend class Ogre2Scene;
    };
    }
  }
}
#endif
