/*
 * Copyright (c) 2017 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>

// INTERNAL INCLUDES
#include "shared/view.h"
#include "shared/utility.h"

using namespace Dali;

namespace
{
const char* MATERIAL_SAMPLE( DEMO_IMAGE_DIR "gallery-small-48.jpg" );
const char* MATERIAL_SAMPLE2( DEMO_IMAGE_DIR "gallery-medium-19.jpg" );

#define MAKE_SHADER(A)#A

const char* VERTEX_SHADER = MAKE_SHADER(
attribute mediump vec2    aPosition;
attribute highp   vec2    aTexCoord;
varying   mediump vec2    vTexCoord;
uniform   mediump mat4    uMvpMatrix;
uniform   mediump vec3    uSize;
uniform   lowp    vec4    uFadeColor;

void main()
{
  mediump vec4 vertexPosition = vec4(aPosition, 0.0, 1.0);
  vertexPosition.xyz *= uSize;
  vertexPosition = uMvpMatrix * vertexPosition;
  vTexCoord = aTexCoord;
  gl_Position = vertexPosition;
}
);

const char* FRAGMENT_SHADER = MAKE_SHADER(
varying mediump vec2  vTexCoord;
uniform lowp    vec4  uColor;
uniform sampler2D     sTexture;
uniform lowp    vec4  uFadeColor;

void main()
{
  gl_FragColor = texture2D( sTexture, vTexCoord ) * uColor * uFadeColor;
}
);

/**
 * Sinusoidal curve starting at zero with 2 cycles
 */
float AlphaFunctionSineX2(float progress)
{
  return 0.5f - cosf(progress * 4.0f * Math::PI) * 0.5f;
}

} // anonymous namespace

// This example shows how to use a simple mesh
//
class ExampleController : public ConnectionTracker
{
public:

  /**
   * The example controller constructor.
   * @param[in] application The application instance
   */
  ExampleController( Application& application )
  : mApplication( application )
  {
    // Connect to the Application's Init signal
    mApplication.InitSignal().Connect( this, &ExampleController::Create );
  }

  /**
   * The example controller destructor
   */
  ~ExampleController()
  {
    // Nothing to do here;
  }

  /**
   * Invoked upon creation of application
   * @param[in] application The application instance
   */
  void Create( Application& application )
  {
    // The Init signal is received once (only) during the Application lifetime

    Stage stage = Stage::GetCurrent();
    stage.KeyEventSignal().Connect(this, &ExampleController::OnKeyEvent);

    mStageSize = stage.GetSize();

    // Hide the indicator bar
    application.GetWindow().ShowIndicator( Dali::Window::INVISIBLE );

    Texture texture1 = DemoHelper::LoadTexture( MATERIAL_SAMPLE );
    Texture texture2 = DemoHelper::LoadTexture( MATERIAL_SAMPLE2 );

    mShader = Shader::New( VERTEX_SHADER, FRAGMENT_SHADER );
    mTextureSet1 = TextureSet::New();
    mTextureSet1.SetTexture( 0u, texture1 );

    mTextureSet2 = TextureSet::New();
    mTextureSet2.SetTexture( 0u, texture2 );

    mGeometry = DemoHelper::CreateTexturedQuad();

    mRenderer = Renderer::New( mGeometry, mShader );
    mRenderer.SetTextures( mTextureSet1 );

    mMeshActor = Actor::New();
    mMeshActor.AddRenderer( mRenderer );
    mMeshActor.SetSize(400, 400);

    Property::Index fadeColorIndex = mRenderer.RegisterProperty( "uFadeColor", Color::MAGENTA );
    mRenderer.SetProperty( Renderer::Property::DEPTH_INDEX, 0 );

    mMeshActor.SetParentOrigin( ParentOrigin::TOP_CENTER );
    mMeshActor.SetAnchorPoint( AnchorPoint::TOP_CENTER );
    stage.Add( mMeshActor );

    mRenderer2 = Renderer::New( mGeometry, mShader );
    mRenderer2.SetTextures( mTextureSet2 );

    mMeshActor2 = Actor::New();
    mMeshActor2.AddRenderer( mRenderer2 );
    mMeshActor2.SetSize(400, 400);

    mMeshActor2.RegisterProperty( "anotherProperty",    Color::GREEN );

    mRenderer2.RegisterProperty( "anotherProperty",    Vector3::ZERO );
    mRenderer2.RegisterProperty( "aCoefficient",  0.008f );
    Property::Index fadeColorIndex2 = mRenderer2.RegisterProperty( "uFadeColor", Color::BLUE );
    mRenderer2.SetProperty( Renderer::Property::DEPTH_INDEX, 0 );

    mMeshActor2.SetParentOrigin( ParentOrigin::BOTTOM_CENTER );
    mMeshActor2.SetAnchorPoint( AnchorPoint::BOTTOM_CENTER );
    stage.Add( mMeshActor2 );

    Animation  animation = Animation::New(5);
    KeyFrames keyFrames = KeyFrames::New();
    keyFrames.Add(0.0f, Vector4::ZERO);
    keyFrames.Add(1.0f, Vector4( Color::GREEN ));

    KeyFrames keyFrames2 = KeyFrames::New();
    keyFrames2.Add(0.0f, Vector4::ZERO);
    keyFrames2.Add(1.0f, Color::MAGENTA);

    animation.AnimateBetween( Property( mRenderer, fadeColorIndex ), keyFrames, AlphaFunction(AlphaFunction::SIN) );
    animation.AnimateBetween( Property( mRenderer2, fadeColorIndex2 ), keyFrames2, AlphaFunction(AlphaFunctionSineX2) );
    animation.SetLooping(true);
    animation.Play();

    stage.SetBackgroundColor(Vector4(0.0f, 0.2f, 0.2f, 1.0f));
  }

  /**
   * Invoked whenever the quit button is clicked
   * @param[in] button the quit button
   */
  bool OnQuitButtonClicked( Toolkit::Button button )
  {
    // quit the application
    mApplication.Quit();
    return true;
  }

  void OnKeyEvent(const KeyEvent& event)
  {
    if(event.state == KeyEvent::Down)
    {
      if( IsKey( event, Dali::DALI_KEY_ESCAPE) || IsKey( event, Dali::DALI_KEY_BACK) )
      {
        mApplication.Quit();
      }
    }
  }

private:

  Application&  mApplication;                             ///< Application instance
  Vector3 mStageSize;                                     ///< The size of the stage

  Shader   mShader;
  TextureSet mTextureSet1;
  TextureSet mTextureSet2;
  Geometry mGeometry;
  Renderer mRenderer;
  Actor    mMeshActor;
  Renderer mRenderer2;
  Actor    mMeshActor2;
  Timer    mChangeImageTimer;
};

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