//============================================================================
//  Copyright (c) Kitware, Inc.
//  All rights reserved.
//  See LICENSE.txt for details.
//  This software is distributed WITHOUT ANY WARRANTY; without even
//  the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
//  PURPOSE.  See the above copyright notice for more information.
//
//  Copyright 2014 Sandia Corporation.
//  Copyright 2014 UT-Battelle, LLC.
//  Copyright 2014 Los Alamos National Security.
//
//  Under the terms of Contract DE-AC04-94AL85000 with Sandia Corporation,
//  the U.S. Government retains certain rights in this software.
//
//  Under the terms of Contract DE-AC52-06NA25396 with Los Alamos National
//  Laboratory (LANL), the U.S. Government retains certain rights in
//  this software.
//============================================================================
#include <iostream>

#include <vtkm/Math.h>
#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/cont/RuntimeDeviceInformation.h>

#include <vtkm/worklet/DispatcherMapField.h>
#include <vtkm/worklet/WorkletMapField.h>

#include <vtkm/cont/cuda/DeviceAdapterCuda.h>
#include <vtkm/cont/tbb/DeviceAdapterTBB.h>
#include <vtkm/cont/serial/DeviceAdapterSerial.h>
#include <vtkm/cont/TryExecute.h>

typedef vtkm::Vec< vtkm::Float32, 3 > FloatVec3;
typedef vtkm::Vec< vtkm::UInt8, 4 > Uint8Vec4;

struct GenerateSurfaceWorklet : public vtkm::worklet::WorkletMapField
{
  vtkm::Float32 t;
  GenerateSurfaceWorklet(vtkm::Float32 st) : t(st) {}

  typedef void ControlSignature( FieldIn<>, FieldOut<>, FieldOut<> );
  typedef void ExecutionSignature( _1, _2, _3 );

  template<typename T>
  VTKM_EXEC
  void operator()( const vtkm::Vec< T, 3 > & input,
                   vtkm::Vec<T, 3> & output,
                   vtkm::Vec<vtkm::UInt8, 4>& color ) const
  {
    output[0] = input[0];
    output[1] = 0.25f * vtkm::Sin( input[0] * 10.f + t ) * vtkm::Cos( input[2] * 10.f + t );
    output[2] = input[2];

    color[0] = 0;
    color[1] = static_cast<vtkm::UInt8>(160 + (96 * vtkm::Sin(input[0] * 10.f + t)));
    color[2] = static_cast<vtkm::UInt8>(160 + (96 * vtkm::Cos(input[2] * 5.f + t)));
    color[3] = 255;
  }
};

struct RunGenerateSurfaceWorklet
{
  template<typename DeviceAdapterTag>
  bool operator()(DeviceAdapterTag ) const
  {
    //At this point we know we have runtime support
    typedef vtkm::cont::DeviceAdapterTraits<DeviceAdapterTag> DeviceTraits;

    typedef vtkm::worklet::DispatcherMapField<GenerateSurfaceWorklet,
                                              DeviceAdapterTag> DispatcherType;

    std::cout << "Running a worklet on device adapter: "
              << DeviceTraits::GetName() << std::endl;

     GenerateSurfaceWorklet worklet( 0.05f );
     DispatcherType(worklet).Invoke( this->In,
                                     this->Out,
                                     this->Color);

     return true;
  }

  vtkm::cont::ArrayHandle< FloatVec3 > In;
  vtkm::cont::ArrayHandle< FloatVec3 > Out;
  vtkm::cont::ArrayHandle< Uint8Vec4 > Color;
};


template<typename T>
std::vector< vtkm::Vec<T, 3> > make_testData(int size)
{
  std::vector< vtkm::Vec< T, 3 > > data;
  data.reserve( static_cast<std::size_t>(size*size) );
  for (int i = 0; i < size; ++i )
    {
    for (int j = 0; j < size; ++j )
      {
        data.push_back( vtkm::Vec<T,3>(2.f*static_cast<T>(i/size)-1.f,
                                       0.f,
                                       2.f*static_cast<T>(j/size)-1.f));
      }
    }
  return data;
}

//This is the list of devices to compile in support for. The order of the
//devices determines the runtime preference.
struct DevicesToTry
    : vtkm::ListTagBase<
        vtkm::cont::DeviceAdapterTagCuda,
        vtkm::cont::DeviceAdapterTagTBB,
        vtkm::cont::DeviceAdapterTagSerial> {  };


int main(int, char**)
{
  std::vector< FloatVec3 > data = make_testData<vtkm::Float32>(1024);

  //make array handles for the data


  // TryExecutes takes a functor and a list of devices. It then tries to run
  // the functor for each device (in the order given in the list) until the
  // execution succeeds. This allows you to compile in support for multiple
  // devices which have runtime requirements ( GPU / HW Accelerator ) and
  // correctly choose the best device at runtime.
  //
  // The functor parentheses operator should take exactly one argument, which is
  // the DeviceAdapterTag to use. The functor should return true if the execution
  // succeeds.
  //
  // This function also optionally takes a vtkm::cont::RuntimeDeviceTracker, which
  // will monitor for certain failures across calls to TryExecute and skip trying
  // devices with a history of failure.
  RunGenerateSurfaceWorklet task;
  task.In = vtkm::cont::make_ArrayHandle(data);
  vtkm::cont::TryExecute(task, DevicesToTry());

}


