/*
 * Copyright (c) 2021 Samsung Electronics Co., Ltd.
 *
 * 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.
 *
 */

// EXTERNAL INCLUDES
#include <dali-toolkit/dali-toolkit.h>

#include <stdio.h>
#include <sstream>

// INTERNAL INCLUDES
#include <dali/devel-api/adaptor-framework/file-stream.h>
#include <dali/integration-api/debug.h>
#include "ktx-loader.h"
#include "model-pbr.h"
#include "model-skybox.h"

using namespace Dali;
using namespace Toolkit;

/*
 *
 * "papermill_pmrem.ktx" and "papermill_E_diffuse-64.ktx are image files generated from
 * image file downloaded from "http://www.hdrlabs.com/sibl/archive.html" with title
 * "Papermill Ruins E" by Blochi and is licensed under Creative Commons License
 * http://creativecommons.org/licenses/by-nc-sa/3.0/us/
 *
*/

namespace
{
const char* NORMAL_ROUGH_TEXTURE_URL     = DEMO_IMAGE_DIR "Test_100_normal_roughness.png";
const char* ALBEDO_METAL_TEXTURE_URL     = DEMO_IMAGE_DIR "Test_wblue_100_albedo_metal.png";
const char* CUBEMAP_SPECULAR_TEXTURE_URL = DEMO_IMAGE_DIR "papermill_pmrem.ktx";
const char* CUBEMAP_DIFFUSE_TEXTURE_URL  = DEMO_IMAGE_DIR "papermill_E_diffuse-64.ktx";

const char* SPHERE_URL = DEMO_MODEL_DIR "sphere.obj";
const char* TEAPOT_URL = DEMO_MODEL_DIR "teapot.obj";

const char* VERTEX_SHADER_URL   = DEMO_SHADER_DIR "pbr_shader.vsh";
const char* FRAGMENT_SHADER_URL = DEMO_SHADER_DIR "pbr_shader.fsh";

const Vector3 SKYBOX_SCALE(1.0f, 1.0f, 1.0f);
const Vector3 SPHERE_SCALE(1.5f, 1.5f, 1.5f);
const Vector3 TEAPOT_SCALE(2.0f, 2.0f, 2.0f);

const float   CAMERA_DEFAULT_FOV(60.0f);
const float   CAMERA_DEFAULT_NEAR(0.1f);
const float   CAMERA_DEFAULT_FAR(1000.0f);
const Vector3 CAMERA_DEFAULT_POSITION(0.0f, 0.0f, 3.5f);

} // namespace

/*
 *
 * This example shows a Physically Based Rendering illumination model.
 *
 * - Double-tap to toggle between 3D models (teapot & cube)
 * - Pan up/down on left side of screen to change roughness
 * - Pan up/down on right side of screen to change metalness
 * - Pan anywhere else to rotate scene
 *
*/

class BasicPbrController : public ConnectionTracker
{
public:
  BasicPbrController(Application& application)
  : mApplication(application),
    mLabel(),
    m3dRoot(),
    mUiRoot(),
    mDoubleTapTime(),
    mModelOrientation(),
    mRoughness(1.f),
    mMetalness(0.f),
    mDoubleTap(false),
    mTeapotView(true)
  {
    // Connect to the Application's Init signal
    mApplication.InitSignal().Connect(this, &BasicPbrController::Create);
  }

  ~BasicPbrController()
  {
    // Nothing to do here;
  }

  // The Init signal is received once (only) during the Application lifetime
  void Create(Application& application)
  {
    // Get a handle to the window
    Window window = application.GetWindow();
    window.SetBackgroundColor(Color::BLACK);
    mAnimation = Animation::New(1.0f);
    mLabel     = TextLabel::New("R:1 M:0");
    mLabel.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::TOP_CENTER);
    mLabel.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::TOP_CENTER);
    mLabel.SetProperty(Actor::Property::SIZE, Vector2(window.GetSize().GetWidth() * 0.75f, window.GetSize().GetHeight() * 0.083f));
    mLabel.SetProperty(TextLabel::Property::HORIZONTAL_ALIGNMENT, "CENTER");
    mLabel.SetProperty(TextLabel::Property::VERTICAL_ALIGNMENT, "CENTER");
    mLabel.SetProperty(TextLabel::Property::TEXT_COLOR, Color::WHITE);
    mLabel.SetProperty(Actor::Property::COLOR_ALPHA, 0.0f);
    // Step 1. Create shader
    CreateModelShader();

    // Step 2. Create texture
    CreateTexture();

    // Step 3. Initialise Main Actor
    InitActors();

    // Respond to a click anywhere on the window
    window.GetRootLayer().TouchedSignal().Connect(this, &BasicPbrController::OnTouch);

    // Respond to key events
    window.KeyEventSignal().Connect(this, &BasicPbrController::OnKeyEvent);

    mDoubleTapTime = Timer::New(150);
    mDoubleTapTime.TickSignal().Connect(this, &BasicPbrController::OnDoubleTapTime);
  }

  bool OnDoubleTapTime()
  {
    mDoubleTap = false;
    return true;
  }

  /**
   * This function will change the material Roughness, Metalness or the model orientation when touched
   */
  bool OnTouch(Actor actor, const TouchEvent& touch)
  {
    const PointState::Type state = touch.GetState(0);

    switch(state)
    {
      case PointState::DOWN:
      {
        if(mDoubleTap)
        {
          mTeapotView = !mTeapotView;
          mModel[0].GetActor().SetProperty(Dali::Actor::Property::VISIBLE, !mTeapotView);
          mModel[1].GetActor().SetProperty(Dali::Actor::Property::VISIBLE, mTeapotView);
        }
        mDoubleTapTime.Stop();
        mStartTouch = touch.GetScreenPosition(0);
        mPointZ     = mStartTouch;
        mAnimation.Stop();
        mLabel.SetProperty(Actor::Property::COLOR_ALPHA, 1.0f);
        break;
      }
      case PointState::MOTION:
      {
        const Window  window  = mApplication.GetWindow();
        const Size    size    = window.GetSize();
        const float   scaleX  = size.width;
        const float   scaleY  = size.height;
        const Vector2 point   = touch.GetScreenPosition(0);
        bool          process = false;
        if((mStartTouch.x < (scaleX * 0.3f)) && (point.x < (scaleX * 0.3f)))
        {
          mRoughness += (mStartTouch.y - point.y) / (scaleY * 0.9f);

          //Clamp Roughness to 0.0 to 1.0
          mRoughness = std::max(0.f, std::min(1.f, mRoughness));

          mShader.SetProperty(mShader.GetPropertyIndex("uRoughness"), mRoughness);
          std::ostringstream oss;
          oss.precision(2);
          oss << " R:" << mRoughness << ","
              << " M:" << mMetalness;
          mLabel.SetProperty(TextLabel::Property::TEXT, oss.str());
          mStartTouch = point;
          process     = true;
        }
        if((mStartTouch.x > (scaleX * 0.7f)) && (point.x > (scaleX * 0.7f)))
        {
          mMetalness += (mStartTouch.y - point.y) / (scaleY * 0.9f);

          //Clamp Metalness to 0.0 to 1.0
          mMetalness = std::max(0.f, std::min(1.f, mMetalness));

          mShader.SetProperty(mShader.GetPropertyIndex("uMetallic"), mMetalness);
          std::ostringstream oss;
          oss.precision(2);
          oss << " R:" << mRoughness << ","
              << " M:" << mMetalness;
          mLabel.SetProperty(TextLabel::Property::TEXT, oss.str());
          mStartTouch = point;
          process     = true;
        }
        //If the touch is not processed above, then change the model orientation
        if(!process)
        {
          process            = true;
          const float angle1 = ((mPointZ.y - point.y) / scaleY);
          const float angle2 = ((mPointZ.x - point.x) / scaleX);
          Actor       actor1 = mModel[0].GetActor();
          Actor       actor2 = mModel[1].GetActor();

          Quaternion modelOrientation = mModelOrientation;
          modelOrientation.Conjugate();
          const Quaternion pitchRot(Radian(Degree(angle1 * -200.0f)), modelOrientation.Rotate(Vector3::XAXIS));
          const Quaternion yawRot(Radian(Degree(angle2 * -200.0f)), modelOrientation.Rotate(Vector3::YAXIS));

          mModelOrientation = mModelOrientation * yawRot * pitchRot;
          mSkybox.GetActor().SetProperty(Actor::Property::ORIENTATION, mModelOrientation);
          actor1.SetProperty(Actor::Property::ORIENTATION, mModelOrientation);
          actor2.SetProperty(Actor::Property::ORIENTATION, mModelOrientation);

          mPointZ = point;
        }
        break;
      }
      case PointState::UP:
      {
        mDoubleTapTime.Start();
        mDoubleTap = true;
        mAnimation.AnimateTo(Property(mLabel, Actor::Property::COLOR_ALPHA), 0.0f, TimePeriod(0.5f, 1.0f));
        mAnimation.Play();
        break;
      }

      default:
      {
        break;
      }
    }
    return true;
  }

  /**
   * @brief Called when any key event is received
   *
   * Will use this to quit the application if Back or the Escape key is received
   * @param[in] event The key event information
   */
  void OnKeyEvent(const KeyEvent& event)
  {
    if(event.GetState() == KeyEvent::DOWN)
    {
      if(IsKey(event, Dali::DALI_KEY_ESCAPE) || IsKey(event, Dali::DALI_KEY_BACK))
      {
        mApplication.Quit();
      }
    }
  }

  /**
   * Creates new main actor
   */
  void InitActors()
  {
    Window  window     = mApplication.GetWindow();
    Vector2 windowSize = window.GetSize();

    mSkybox.Init(SKYBOX_SCALE);
    mModel[0].Init(mShader, SPHERE_URL, Vector3::ZERO, SPHERE_SCALE);
    mModel[1].Init(mShader, TEAPOT_URL, Vector3::ZERO, TEAPOT_SCALE);

    // Hide the model according with mTeapotView variable
    mModel[0].GetActor().SetProperty(Dali::Actor::Property::VISIBLE, !mTeapotView);
    mModel[1].GetActor().SetProperty(Dali::Actor::Property::VISIBLE, mTeapotView);

    // Creating root and camera actor for rendertask for 3D Scene rendering
    mUiRoot              = Actor::New();
    m3dRoot              = Actor::New();
    CameraActor cameraUi = CameraActor::New(window.GetSize());
    cameraUi.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::CENTER);
    cameraUi.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);

    RenderTask rendertask = window.GetRenderTaskList().CreateTask();
    rendertask.SetCameraActor(cameraUi);
    rendertask.SetSourceActor(mUiRoot);

    mUiRoot.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::TOP_LEFT);
    mUiRoot.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::TOP_LEFT);
    mUiRoot.SetProperty(Actor::Property::SIZE, Vector2(window.GetSize()));

    m3dRoot.SetProperty(Actor::Property::ANCHOR_POINT, AnchorPoint::CENTER);
    m3dRoot.SetProperty(Actor::Property::PARENT_ORIGIN, ParentOrigin::CENTER);

    // Setting camera parameters for 3D Scene
    mSkybox.GetActor().SetProperty(Actor::Property::POSITION, CAMERA_DEFAULT_POSITION);
    CameraActor camera3d = window.GetRenderTaskList().GetTask(0).GetCameraActor();
    camera3d.SetInvertYAxis(true);
    camera3d.SetProperty(Actor::Property::POSITION, CAMERA_DEFAULT_POSITION);
    camera3d.SetNearClippingPlane(CAMERA_DEFAULT_NEAR);
    camera3d.SetFarClippingPlane(CAMERA_DEFAULT_FAR);
    camera3d.SetFieldOfView(Radian(Degree(CAMERA_DEFAULT_FOV)));

    window.Add(cameraUi);
    window.Add(mUiRoot);
    window.Add(m3dRoot);

    m3dRoot.Add(mSkybox.GetActor());
    m3dRoot.Add(mModel[0].GetActor());
    m3dRoot.Add(mModel[1].GetActor());

    if((windowSize.x > 360.0f) && (windowSize.y > 360.0f))
    {
      mUiRoot.Add(mLabel);
    }
  }

  /**
   * Creates a shader using file path
   */
  void CreateModelShader()
  {
    const std::string mCurrentVShaderFile(VERTEX_SHADER_URL);
    const std::string mCurrentFShaderFile(FRAGMENT_SHADER_URL);

    mShader = LoadShaders(mCurrentVShaderFile, mCurrentFShaderFile);

    // Initialise shader uniforms
    // Level 8 because the environment texture has 6 levels plus 2 are missing (2x2 and 1x1)
    mShader.RegisterProperty("uMaxLOD", 8.0f);
    mShader.RegisterProperty("uRoughness", 1.0f);
    mShader.RegisterProperty("uMetallic", 0.0f);
  }

  /**
   * Create Textures
   */
  void CreateTexture()
  {
    PixelData albeldoPixelData   = SyncImageLoader::Load(ALBEDO_METAL_TEXTURE_URL);
    Texture   textureAlbedoMetal = Texture::New(TextureType::TEXTURE_2D, albeldoPixelData.GetPixelFormat(), albeldoPixelData.GetWidth(), albeldoPixelData.GetHeight());
    textureAlbedoMetal.Upload(albeldoPixelData, 0, 0, 0, 0, albeldoPixelData.GetWidth(), albeldoPixelData.GetHeight());

    PixelData normalPixelData    = SyncImageLoader::Load(NORMAL_ROUGH_TEXTURE_URL);
    Texture   textureNormalRough = Texture::New(TextureType::TEXTURE_2D, normalPixelData.GetPixelFormat(), normalPixelData.GetWidth(), normalPixelData.GetHeight());
    textureNormalRough.Upload(normalPixelData, 0, 0, 0, 0, normalPixelData.GetWidth(), normalPixelData.GetHeight());

    // This texture should have 6 faces and only one mipmap
    PbrDemo::CubeData diffuse;
    PbrDemo::LoadCubeMapFromKtxFile(CUBEMAP_DIFFUSE_TEXTURE_URL, diffuse);

    Texture diffuseTexture = Texture::New(TextureType::TEXTURE_CUBE, diffuse.img[0][0].GetPixelFormat(), diffuse.img[0][0].GetWidth(), diffuse.img[0][0].GetHeight());
    for(unsigned int midmapLevel = 0; midmapLevel < diffuse.img[0].size(); ++midmapLevel)
    {
      for(unsigned int i = 0; i < diffuse.img.size(); ++i)
      {
        diffuseTexture.Upload(diffuse.img[i][midmapLevel], CubeMapLayer::POSITIVE_X + i, midmapLevel, 0, 0, diffuse.img[i][midmapLevel].GetWidth(), diffuse.img[i][midmapLevel].GetHeight());
      }
    }

    // This texture should have 6 faces and 6 mipmaps
    PbrDemo::CubeData specular;
    PbrDemo::LoadCubeMapFromKtxFile(CUBEMAP_SPECULAR_TEXTURE_URL, specular);

    Texture specularTexture = Texture::New(TextureType::TEXTURE_CUBE, specular.img[0][0].GetPixelFormat(), specular.img[0][0].GetWidth(), specular.img[0][0].GetHeight());
    for(unsigned int midmapLevel = 0; midmapLevel < specular.img[0].size(); ++midmapLevel)
    {
      for(unsigned int i = 0; i < specular.img.size(); ++i)
      {
        specularTexture.Upload(specular.img[i][midmapLevel], CubeMapLayer::POSITIVE_X + i, midmapLevel, 0, 0, specular.img[i][midmapLevel].GetWidth(), specular.img[i][midmapLevel].GetHeight());
      }
    }

    mModel[0].InitTexture(textureAlbedoMetal, textureNormalRough, diffuseTexture, specularTexture);
    mModel[1].InitTexture(textureAlbedoMetal, textureNormalRough, diffuseTexture, specularTexture);
    mSkybox.InitTexture(specularTexture);
  }

  /**
  * @brief Load a shader source file
  * @param[in] The path of the source file
  * @param[out] The contents of file
  * @return True if the source was read successfully
  */
  bool LoadShaderCode(const std::string& fullpath, std::vector<char>& output)
  {
    Dali::FileStream fileStream(fullpath, FileStream::READ | FileStream::BINARY);
    FILE*            file = fileStream.GetFile();
    if(NULL == file)
    {
      return false;
    }

    bool retValue = false;
    if(!fseek(file, 0, SEEK_END))
    {
      long int size = ftell(file);

      if((size != -1L) &&
         (!fseek(file, 0, SEEK_SET)))
      {
        output.resize(size + 1);
        std::fill(output.begin(), output.end(), 0);
        ssize_t result = fread(output.data(), size, 1, file);

        retValue = (result >= 0);
      }
    }

    return retValue;
  }

  /**
  * @brief Load vertex and fragment shader source
  * @param[in] shaderVertexFileName is the filepath of Vertex shader
  * @param[in] shaderFragFileName is the filepath of Fragment shader
  * @return the Dali::Shader object
  */
  Shader LoadShaders(const std::string& shaderVertexFileName, const std::string& shaderFragFileName)
  {
    Shader            shader;
    std::vector<char> bufV, bufF;

    if(LoadShaderCode(shaderVertexFileName.c_str(), bufV))
    {
      if(LoadShaderCode(shaderFragFileName.c_str(), bufF))
      {
        shader = Shader::New(bufV.data(), bufF.data());
      }
    }
    return shader;
  }

private:
  Application& mApplication;
  TextLabel    mLabel;
  Actor        m3dRoot;
  Actor        mUiRoot;
  Shader       mShader;
  Animation    mAnimation;
  Timer        mDoubleTapTime;

  ModelSkybox mSkybox;
  ModelPbr    mModel[2];

  Vector2 mPointZ;
  Vector2 mStartTouch;

  Quaternion mModelOrientation;
  float      mRoughness;
  float      mMetalness;
  bool       mDoubleTap;
  bool       mTeapotView;
};

int DALI_EXPORT_API main(int argc, char** argv)
{
  Application        application = Application::New(&argc, &argv);
  BasicPbrController test(application);
  application.MainLoop();
  return 0;
}