//============================================================================
//  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.
//============================================================================

#ifndef vtk_m_exec_serial_internal_TaskTiling_h
#define vtk_m_exec_serial_internal_TaskTiling_h

#include <vtkm/exec/TaskBase.h>

//Todo: rename this header to TaskInvokeWorkletDetail.h
#include <vtkm/exec/internal/WorkletInvokeFunctorDetail.h>

namespace vtkm
{
namespace exec
{
namespace serial
{
namespace internal
{

template <typename WType>
void VTKM_NEVER_EXPORT
TaskTilingSetErrorBuffer(void* w, const vtkm::exec::internal::ErrorMessageBuffer& buffer)
{
  using WorkletType = typename std::remove_cv<WType>::type;
  WorkletType* const worklet = static_cast<WorkletType*>(w);
  worklet->SetErrorMessageBuffer(buffer);
}

template <typename WType, typename IType>
void VTKM_NEVER_EXPORT TaskTiling1DExecute(void* w,
                                           void* const v,
                                           vtkm::Id globalIndexOffset,
                                           vtkm::Id start,
                                           vtkm::Id end)
{
  using WorkletType = typename std::remove_cv<WType>::type;
  using InvocationType = typename std::remove_cv<IType>::type;

  WorkletType const* const worklet = static_cast<WorkletType*>(w);
  InvocationType const* const invocation = static_cast<InvocationType*>(v);

  for (vtkm::Id index = start; index < end; ++index)
  {
    //Todo: rename this function to DoTaskInvokeWorklet
    vtkm::exec::internal::detail::DoWorkletInvokeFunctor(
      *worklet,
      *invocation,
      worklet->GetThreadIndices(index,
                                invocation->OutputToInputMap,
                                invocation->VisitArray,
                                invocation->ThreadToOutputMap,
                                invocation->GetInputDomain(),
                                globalIndexOffset));
  }
}

template <typename FType>
void VTKM_NEVER_EXPORT
FunctorTiling1DExecute(void* f, void* const, vtkm::Id, vtkm::Id start, vtkm::Id end)
{
  using FunctorType = typename std::remove_cv<FType>::type;
  FunctorType const* const functor = static_cast<FunctorType*>(f);

  for (vtkm::Id index = start; index < end; ++index)
  {
    functor->operator()(index);
  }
}

template <typename WType, typename IType>
void VTKM_NEVER_EXPORT TaskTiling3DExecute(void* w,
                                           void* const v,
                                           vtkm::Id globalIndexOffset,
                                           vtkm::Id istart,
                                           vtkm::Id iend,
                                           vtkm::Id j,
                                           vtkm::Id k)
{
  using WorkletType = typename std::remove_cv<WType>::type;
  using InvocationType = typename std::remove_cv<IType>::type;

  WorkletType const* const worklet = static_cast<WorkletType*>(w);
  InvocationType const* const invocation = static_cast<InvocationType*>(v);

  vtkm::Id3 index(istart, j, k);
  for (vtkm::Id i = istart; i < iend; ++i)
  {
    index[0] = i;
    //Todo: rename this function to DoTaskInvokeWorklet
    vtkm::exec::internal::detail::DoWorkletInvokeFunctor(
      *worklet,
      *invocation,
      worklet->GetThreadIndices(index,
                                invocation->OutputToInputMap,
                                invocation->VisitArray,
                                invocation->ThreadToOutputMap,
                                invocation->GetInputDomain(),
                                globalIndexOffset));
  }
}

template <typename FType>
void VTKM_NEVER_EXPORT FunctorTiling3DExecute(void* f,
                                              void* const,
                                              vtkm::Id,
                                              vtkm::Id istart,
                                              vtkm::Id iend,
                                              vtkm::Id j,
                                              vtkm::Id k)
{
  using FunctorType = typename std::remove_cv<FType>::type;
  FunctorType const* const functor = static_cast<FunctorType*>(f);

  vtkm::Id3 index(istart, j, k);
  for (vtkm::Id i = istart; i < iend; ++i)
  {
    index[0] = i;
    functor->operator()(index);
  }
}

// TaskTiling1D represents an execution pattern for a worklet
// that is best expressed in terms of single dimension iteration space. TaskTiling1D
// also states that for best performance a linear consecutive range of values
// should be given to the worklet for optimal performance.
//
// Note: The worklet and invocation must have a lifetime that is at least
// as long as the Task
class VTKM_ALWAYS_EXPORT TaskTiling1D : public vtkm::exec::TaskBase
{
public:
  TaskTiling1D()
    : Worklet(nullptr)
    , Invocation(nullptr)
    , GlobalIndexOffset(0)
  {
  }

  /// This constructor supports general functors that which have a call
  /// operator with the signature:
  ///   operator()(vtkm::Id)
  template <typename FunctorType>
  TaskTiling1D(FunctorType& functor)
    : Worklet(nullptr)
    , Invocation(nullptr)
    , ExecuteFunction(nullptr)
    , SetErrorBufferFunction(nullptr)
    , GlobalIndexOffset(0)
  {
    //Setup the execute and set error buffer function pointers
    this->ExecuteFunction = &FunctorTiling1DExecute<FunctorType>;
    this->SetErrorBufferFunction = &TaskTilingSetErrorBuffer<FunctorType>;

    //Bind the Worklet to void*
    this->Worklet = (void*)&functor;
  }

  /// This constructor supports any vtkm worklet and the associated invocation
  /// parameters that go along with it
  template <typename WorkletType, typename InvocationType>
  TaskTiling1D(WorkletType& worklet, InvocationType& invocation, vtkm::Id globalIndexOffset)
    : Worklet(nullptr)
    , Invocation(nullptr)
    , ExecuteFunction(nullptr)
    , SetErrorBufferFunction(nullptr)
    , GlobalIndexOffset(globalIndexOffset)
  {
    //Setup the execute and set error buffer function pointers
    this->ExecuteFunction = &TaskTiling1DExecute<WorkletType, InvocationType>;
    this->SetErrorBufferFunction = &TaskTilingSetErrorBuffer<WorkletType>;

    //Bind the Worklet and Invocation to void*
    this->Worklet = (void*)&worklet;
    this->Invocation = (void*)&invocation;
  }

  /// explicit Copy constructor.
  /// Note this required so that compilers don't use the templated constructor
  /// as the copy constructor which will cause compile issues
  TaskTiling1D(TaskTiling1D& task)
    : Worklet(task.Worklet)
    , Invocation(task.Invocation)
    , ExecuteFunction(task.ExecuteFunction)
    , SetErrorBufferFunction(task.SetErrorBufferFunction)
    , GlobalIndexOffset(task.GlobalIndexOffset)
  {
  }

  TaskTiling1D(TaskTiling1D&& task) = default;

  void SetErrorMessageBuffer(const vtkm::exec::internal::ErrorMessageBuffer& buffer)
  {
    this->SetErrorBufferFunction(this->Worklet, buffer);
  }

  void operator()(vtkm::Id start, vtkm::Id end) const
  {
    this->ExecuteFunction(this->Worklet, this->Invocation, this->GlobalIndexOffset, start, end);
  }

protected:
  void* Worklet;
  void* Invocation;

  using ExecuteSignature = void (*)(void*, void* const, vtkm::Id, vtkm::Id, vtkm::Id);
  ExecuteSignature ExecuteFunction;

  using SetErrorBufferSignature = void (*)(void*, const vtkm::exec::internal::ErrorMessageBuffer&);
  SetErrorBufferSignature SetErrorBufferFunction;

  const vtkm::Id GlobalIndexOffset;
};

// TaskTiling3D represents an execution pattern for a worklet
// that is best expressed in terms of an 3 dimensional iteration space. TaskTiling3D
// also states that for best performance a linear consecutive range of values
// in the X dimension should be given to the worklet for optimal performance.
//
// Note: The worklet and invocation must have a lifetime that is at least
// as long as the Task
class VTKM_ALWAYS_EXPORT TaskTiling3D : public vtkm::exec::TaskBase
{
public:
  TaskTiling3D()
    : Worklet(nullptr)
    , Invocation(nullptr)
    , GlobalIndexOffset(0)
  {
  }

  /// This constructor supports general functors that which have a call
  /// operator with the signature:
  ///   operator()(vtkm::Id)
  template <typename FunctorType>
  TaskTiling3D(FunctorType& functor)
    : Worklet(nullptr)
    , Invocation(nullptr)
    , ExecuteFunction(nullptr)
    , SetErrorBufferFunction(nullptr)
    , GlobalIndexOffset(0)
  {
    //Setup the execute and set error buffer function pointers
    this->ExecuteFunction = &FunctorTiling3DExecute<FunctorType>;
    this->SetErrorBufferFunction = &TaskTilingSetErrorBuffer<FunctorType>;

    //Bind the Worklet to void*
    this->Worklet = (void*)&functor;
  }

  template <typename WorkletType, typename InvocationType>
  TaskTiling3D(WorkletType& worklet, InvocationType& invocation, vtkm::Id globalIndexOffset = 0)
    : Worklet(nullptr)
    , Invocation(nullptr)
    , ExecuteFunction(nullptr)
    , SetErrorBufferFunction(nullptr)
    , GlobalIndexOffset(globalIndexOffset)
  {
    // Setup the execute and set error buffer function pointers
    this->ExecuteFunction = &TaskTiling3DExecute<WorkletType, InvocationType>;
    this->SetErrorBufferFunction = &TaskTilingSetErrorBuffer<WorkletType>;

    // At this point we bind the Worklet and Invocation to void*
    this->Worklet = (void*)&worklet;
    this->Invocation = (void*)&invocation;
  }

  /// explicit Copy constructor.
  /// Note this required so that compilers don't use the templated constructor
  /// as the copy constructor which will cause compile issues
  TaskTiling3D(TaskTiling3D& task)
    : Worklet(task.Worklet)
    , Invocation(task.Invocation)
    , ExecuteFunction(task.ExecuteFunction)
    , SetErrorBufferFunction(task.SetErrorBufferFunction)
    , GlobalIndexOffset(task.GlobalIndexOffset)
  {
  }

  TaskTiling3D(TaskTiling3D&& task) = default;

  void SetErrorMessageBuffer(const vtkm::exec::internal::ErrorMessageBuffer& buffer)
  {
    this->SetErrorBufferFunction(this->Worklet, buffer);
  }

  void operator()(vtkm::Id istart, vtkm::Id iend, vtkm::Id j, vtkm::Id k) const
  {
    this->ExecuteFunction(
      this->Worklet, this->Invocation, this->GlobalIndexOffset, istart, iend, j, k);
  }

protected:
  void* Worklet;
  void* Invocation;

  using ExecuteSignature =
    void (*)(void*, void* const, vtkm::Id, vtkm::Id, vtkm::Id, vtkm::Id, vtkm::Id);
  ExecuteSignature ExecuteFunction;

  using SetErrorBufferSignature = void (*)(void*, const vtkm::exec::internal::ErrorMessageBuffer&);
  SetErrorBufferSignature SetErrorBufferFunction;

  const vtkm::Id GlobalIndexOffset;
};
}
}
}
} // vtkm::exec::serial::internal

#endif //vtk_m_exec_serial_internal_TaskTiling_h
