//============================================================================
//  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 National Technology & Engineering Solutions of Sandia, LLC (NTESS).
//  Copyright 2014 UT-Battelle, LLC.
//  Copyright 2014 Los Alamos National Security.
//
//  Under the terms of Contract DE-NA0003525 with NTESS,
//  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.
//============================================================================
#ifndef vtk_m_cont_Field_h
#define vtk_m_cont_Field_h

#include <vtkm/cont/vtkm_cont_export.h>

#include <vtkm/Range.h>
#include <vtkm/Types.h>

#include <vtkm/cont/ArrayHandle.h>
#include <vtkm/cont/ArrayPortalToIterators.h>
#include <vtkm/cont/ArrayRangeCompute.h>
#include <vtkm/cont/ArrayRangeCompute.hxx>
#include <vtkm/cont/VariantArrayHandle.h>

namespace vtkm
{
namespace cont
{

namespace internal
{

struct ComputeRange
{
  template <typename ArrayHandleType>
  void operator()(const ArrayHandleType& input, vtkm::cont::ArrayHandle<vtkm::Range>& range) const
  {
    range = vtkm::cont::ArrayRangeCompute(input);
  }
};

} // namespace internal


/// A \c Field encapsulates an array on some piece of the mesh, such as
/// the points, a cell set, a point logical dimension, or the whole mesh.
///
class VTKM_CONT_EXPORT Field
{
public:
  enum struct Association
  {
    ANY,
    WHOLE_MESH,
    POINTS,
    CELL_SET,
    LOGICAL_DIM
  };

  VTKM_CONT
  Field() = default;

  /// constructors for points / whole mesh
  VTKM_CONT
  Field(std::string name, Association association, const vtkm::cont::VariantArrayHandle& data);

  template <typename T, typename Storage>
  VTKM_CONT Field(std::string name,
                  Association association,
                  const vtkm::cont::ArrayHandle<T, Storage>& data)
    : Field(name, association, vtkm::cont::VariantArrayHandle{ data })
  {
  }

  /// constructors for cell set associations
  VTKM_CONT
  Field(std::string name,
        Association association,
        const std::string& cellSetName,
        const vtkm::cont::VariantArrayHandle& data);

  template <typename T, typename Storage>
  VTKM_CONT Field(std::string name,
                  Association association,
                  const std::string& cellSetName,
                  const vtkm::cont::ArrayHandle<T, Storage>& data)
    : Field(name, association, cellSetName, vtkm::cont::VariantArrayHandle{ data })
  {
  }

  /// constructors for logical dimension associations
  VTKM_CONT
  Field(std::string name,
        Association association,
        vtkm::IdComponent logicalDim,
        const vtkm::cont::VariantArrayHandle& data);

  template <typename T, typename Storage>
  VTKM_CONT Field(std::string name,
                  Association association,
                  vtkm::IdComponent logicalDim,
                  const vtkm::cont::ArrayHandle<T, Storage>& data)
    : Field(name, association, logicalDim, vtkm::cont::VariantArrayHandle{ data })
  {
  }

  Field(const vtkm::cont::Field& src);
  Field(vtkm::cont::Field&& src) noexcept;

  VTKM_CONT virtual ~Field();

  VTKM_CONT Field& operator=(const vtkm::cont::Field& src);
  VTKM_CONT Field& operator=(vtkm::cont::Field&& src) noexcept;

  VTKM_CONT const std::string& GetName() const { return this->Name; }
  VTKM_CONT Association GetAssociation() const { return this->FieldAssociation; }
  VTKM_CONT std::string GetAssocCellSet() const { return this->AssocCellSetName; }
  VTKM_CONT vtkm::IdComponent GetAssocLogicalDim() const { return this->AssocLogicalDim; }
  const vtkm::cont::VariantArrayHandle& GetData() const;
  vtkm::cont::VariantArrayHandle& GetData();


  template <typename TypeList>
  VTKM_CONT void GetRange(vtkm::Range* range, TypeList) const
  {
    this->GetRangeImpl(TypeList());
    const vtkm::Id length = this->Range.GetNumberOfValues();
    for (vtkm::Id i = 0; i < length; ++i)
    {
      range[i] = this->Range.GetPortalConstControl().Get(i);
    }
  }

  template <typename TypeList>
  VTKM_CONT const vtkm::cont::ArrayHandle<vtkm::Range>& GetRange(TypeList) const
  {
    return this->GetRangeImpl(TypeList());
  }

  VTKM_CONT
  const vtkm::cont::ArrayHandle<vtkm::Range>& GetRange() const
  {
    return this->GetRangeImpl(VTKM_DEFAULT_TYPE_LIST_TAG());
  };

  VTKM_CONT void GetRange(vtkm::Range* range) const
  {
    return this->GetRange(range, VTKM_DEFAULT_TYPE_LIST_TAG());
  };

  template <typename T, typename StorageTag>
  VTKM_CONT void SetData(const vtkm::cont::ArrayHandle<T, StorageTag>& newdata)
  {
    this->Data = newdata;
    this->ModifiedFlag = true;
  }

  VTKM_CONT
  void SetData(const vtkm::cont::VariantArrayHandle& newdata)
  {
    this->Data = newdata;
    this->ModifiedFlag = true;
  }

  VTKM_CONT
  virtual void PrintSummary(std::ostream& out) const;

  VTKM_CONT
  virtual void ReleaseResourcesExecution()
  {
    this->Data.ReleaseResourcesExecution();
    this->Range.ReleaseResourcesExecution();
  }

private:
  std::string Name; ///< name of field

  Association FieldAssociation = Association::ANY;
  std::string AssocCellSetName;      ///< only populate if assoc is cells
  vtkm::IdComponent AssocLogicalDim; ///< only populate if assoc is logical dim

  vtkm::cont::VariantArrayHandle Data;
  mutable vtkm::cont::ArrayHandle<vtkm::Range> Range;
  mutable bool ModifiedFlag = true;

  template <typename TypeList>
  VTKM_CONT const vtkm::cont::ArrayHandle<vtkm::Range>& GetRangeImpl(TypeList) const
  {
    VTKM_IS_LIST_TAG(TypeList);

    if (this->ModifiedFlag)
    {
      vtkm::cont::CastAndCall(
        this->Data.ResetTypes(TypeList()), internal::ComputeRange{}, this->Range);
      this->ModifiedFlag = false;
    }

    return this->Range;
  }
};

template <typename Functor, typename... Args>
void CastAndCall(const vtkm::cont::Field& field, Functor&& f, Args&&... args)
{
  vtkm::cont::CastAndCall(field.GetData(), std::forward<Functor>(f), std::forward<Args>(args)...);
}

//@{
/// Convenience functions to build fields from C style arrays and std::vector
template <typename T>
vtkm::cont::Field make_Field(std::string name,
                             Field::Association association,
                             const T* data,
                             vtkm::Id size,
                             vtkm::CopyFlag copy = vtkm::CopyFlag::Off)
{
  return vtkm::cont::Field(name, association, vtkm::cont::make_ArrayHandle(data, size, copy));
}

template <typename T>
vtkm::cont::Field make_Field(std::string name,
                             Field::Association association,
                             const std::vector<T>& data,
                             vtkm::CopyFlag copy = vtkm::CopyFlag::Off)
{
  return vtkm::cont::Field(name, association, vtkm::cont::make_ArrayHandle(data, copy));
}

template <typename T>
vtkm::cont::Field make_Field(std::string name,
                             Field::Association association,
                             const std::string& cellSetName,
                             const T* data,
                             vtkm::Id size,
                             vtkm::CopyFlag copy = vtkm::CopyFlag::Off)
{
  return vtkm::cont::Field(
    name, association, cellSetName, vtkm::cont::make_ArrayHandle(data, size, copy));
}

template <typename T>
vtkm::cont::Field make_Field(std::string name,
                             Field::Association association,
                             const std::string& cellSetName,
                             const std::vector<T>& data,
                             vtkm::CopyFlag copy = vtkm::CopyFlag::Off)
{
  return vtkm::cont::Field(
    name, association, cellSetName, vtkm::cont::make_ArrayHandle(data, copy));
}

template <typename T>
vtkm::cont::Field make_Field(std::string name,
                             Field::Association association,
                             vtkm::IdComponent logicalDim,
                             const T* data,
                             vtkm::Id size,
                             vtkm::CopyFlag copy = vtkm::CopyFlag::Off)
{
  return vtkm::cont::Field(
    name, association, logicalDim, vtkm::cont::make_ArrayHandle(data, size, copy));
}

template <typename T>
vtkm::cont::Field make_Field(std::string name,
                             Field::Association association,
                             vtkm::IdComponent logicalDim,
                             const std::vector<T>& data,
                             vtkm::CopyFlag copy = vtkm::CopyFlag::Off)
{
  return vtkm::cont::Field(name, association, logicalDim, vtkm::cont::make_ArrayHandle(data, copy));
}
//@}

} // namespace cont
} // namespace vtkm


namespace vtkm
{
namespace cont
{
namespace internal
{
template <>
struct DynamicTransformTraits<vtkm::cont::Field>
{
  using DynamicTag = vtkm::cont::internal::DynamicTransformTagCastAndCall;
};
} // namespace internal
} // namespace cont
} // namespace vtkm

//=============================================================================
// Specializations of serialization related classes
namespace vtkm
{
namespace cont
{
template <typename TypeList = VTKM_DEFAULT_TYPE_LIST_TAG>
struct SerializableField
{
  SerializableField() = default;

  explicit SerializableField(const vtkm::cont::Field& field)
    : Field(field)
  {
  }

  vtkm::cont::Field Field;
};
} // namespace cont
} // namespace vtkm

namespace diy
{

template <typename TypeList>
struct Serialization<vtkm::cont::SerializableField<TypeList>>
{
private:
  using Type = vtkm::cont::SerializableField<TypeList>;

public:
  static VTKM_CONT void save(BinaryBuffer& bb, const Type& serializable)
  {
    const auto& field = serializable.Field;

    diy::save(bb, field.GetName());
    diy::save(bb, static_cast<int>(field.GetAssociation()));
    if (field.GetAssociation() == vtkm::cont::Field::Association::CELL_SET)
    {
      diy::save(bb, field.GetAssocCellSet());
    }
    else if (field.GetAssociation() == vtkm::cont::Field::Association::LOGICAL_DIM)
    {
      diy::save(bb, field.GetAssocLogicalDim());
    }
    diy::save(bb, field.GetData().ResetTypes(TypeList{}));
  }

  static VTKM_CONT void load(BinaryBuffer& bb, Type& serializable)
  {
    auto& field = serializable.Field;

    std::string name;
    diy::load(bb, name);
    int assocVal = 0;
    diy::load(bb, assocVal);

    auto assoc = static_cast<vtkm::cont::Field::Association>(assocVal);
    vtkm::cont::VariantArrayHandleBase<TypeList> data;
    if (assoc == vtkm::cont::Field::Association::CELL_SET)
    {
      std::string assocCellSetName;
      diy::load(bb, assocCellSetName);
      diy::load(bb, data);
      field =
        vtkm::cont::Field(name, assoc, assocCellSetName, vtkm::cont::VariantArrayHandle(data));
    }
    else if (assoc == vtkm::cont::Field::Association::LOGICAL_DIM)
    {
      vtkm::IdComponent assocLogicalDim;
      diy::load(bb, assocLogicalDim);
      diy::load(bb, data);
      field = vtkm::cont::Field(name, assoc, assocLogicalDim, vtkm::cont::VariantArrayHandle(data));
    }
    else
    {
      diy::load(bb, data);
      field = vtkm::cont::Field(name, assoc, vtkm::cont::VariantArrayHandle(data));
    }
  }
};

} // diy

#endif //vtk_m_cont_Field_h
