/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  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.txt
 *
 *  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.
 *
 *=========================================================================*/
#ifndef itkFFTWCommon_h
#define itkFFTWCommon_h

#if defined( ITK_USE_FFTWF ) || defined( ITK_USE_FFTWD )
#if defined( ITK_USE_CUFFTW )
#include "cufftw.h"
#else
#include "itkFFTWGlobalConfiguration.h"
#include "fftw3.h"
#endif
#if !defined(FFTW_WISDOM_ONLY)
// FFTW_WISDOM_ONLY is a "beyond guru" option that is only available in fftw 3.2.2
// to be compatible with all the fftw 3.x API, we need to define this away here:
#error "FFTW 3.3.2 or later is required so that FFTW_WISDOM_ONLY is defined."
#endif

#endif

#include <mutex>

namespace itk
{
namespace fftw
{
/**
 * \class Interface
 * \brief Wrapper for FFTW API
 *
 * This implementation was taken from the Insight Journal paper:
 * https://hdl.handle.net/10380/3154
 * or http://insight-journal.com/browse/publication/717
 *
 * \author Gaetan Lehmann. Biologie du Developpement et de la Reproduction, INRA de Jouy-en-Josas, France.
 *
 * \ingroup ITKFFT
 */
template< typename TPixel >
class Proxy
{
  // empty -- only double and float specializations work

protected:
  Proxy() {};
  ~Proxy() {};
};

#if defined( ITK_USE_FFTWF )

template< >
class Proxy< float >
{
public:
  using PixelType = float;
  using ComplexType = fftwf_complex;
  using PlanType = fftwf_plan;
  using Self = Proxy<float>;

  // FFTW works with any data size, but is optimized for size decomposition with prime factors up to 13.
#ifdef ITK_USE_CUFFTW
  static constexpr SizeValueType GREATEST_PRIME_FACTOR = 7;
#else
  static constexpr SizeValueType GREATEST_PRIME_FACTOR = 13;
#endif

  static PlanType Plan_dft_c2r_1d(int n,
                                  ComplexType *in,
                                  PixelType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    return Plan_dft_c2r(1, &n, in, out, flags, threads, canDestroyInput);
  }

  static PlanType Plan_dft_c2r_2d(int nx,
                                  int ny,
                                  ComplexType *in,
                                  PixelType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[2];
    sizes[0] = nx;
    sizes[1] = ny;
    PlanType plan = Plan_dft_c2r(2, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_c2r_3d(int nx,
                                  int ny,
                                  int nz,
                                  ComplexType *in,
                                  PixelType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[3];
    sizes[0] = nx;
    sizes[1] = ny;
    sizes[2] = nz;
    PlanType plan = Plan_dft_c2r(3, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_c2r(int rank,
                               const int *n,
                               ComplexType *in,
                               PixelType *out,
                               unsigned flags,
                               int threads=1,
                               bool canDestroyInput=false)
  {
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
    fftwf_plan_with_nthreads(threads);
#else
    (void)threads;
#endif
    // don't add FFTW_WISDOM_ONLY if the plan rigor is FFTW_ESTIMATE
    // because FFTW_ESTIMATE guarantee to not destroy the input
    unsigned roflags = flags;
    if( ! (flags & FFTW_ESTIMATE) )
      {
      roflags = flags | FFTW_WISDOM_ONLY;
      }
    PlanType plan = fftwf_plan_dft_c2r(rank,n,in,out,roflags);
    if( plan == nullptr )
      {
      // no wisdom available for that plan
      if( canDestroyInput )
        {
        // just create the plan
        plan = fftwf_plan_dft_c2r(rank,n,in,out,flags);
        }
      else
        {
        // lets create a plan with a fake input to generate the wisdom
        int total = 1;
        for( int i=0; i<rank; i++ )
          {
          total *= n[i];
          }
        auto * din = new ComplexType[total];
        fftwf_plan_dft_c2r(rank,n,din,out,flags);
        delete[] din;
        // and then create the final plan - this time it shouldn't fail
        plan = fftwf_plan_dft_c2r(rank,n,in,out,roflags);
        }
#ifndef ITK_USE_CUFFTW
      FFTWGlobalConfiguration::SetNewWisdomAvailable(true);
#endif
      }
    itkAssertOrThrowMacro( plan != nullptr , "PLAN_CREATION_FAILED ");
    return plan;
  }


  static PlanType Plan_dft_r2c_1d(int n,
                                  PixelType *in,
                                  ComplexType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    return Plan_dft_r2c(1, &n, in, out, flags, threads, canDestroyInput);
  }

  static PlanType Plan_dft_r2c_2d(int nx,
                                  int ny,
                                  PixelType *in,
                                  ComplexType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[2];
    sizes[0] = nx;
    sizes[1] = ny;
    PlanType plan = Plan_dft_r2c(2, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_r2c_3d(int nx,
                                  int ny,
                                  int nz,
                                  PixelType *in,
                                  ComplexType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[3];
    sizes[0] = nx;
    sizes[1] = ny;
    sizes[2] = nz;
    PlanType plan = Plan_dft_r2c(3, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_r2c(int rank,
                               const int *n,
                               PixelType *in,
                               ComplexType *out,
                               unsigned flags,
                               int threads=1,
                               bool canDestroyInput=false)
  {
    //
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
    fftwf_plan_with_nthreads(threads);
#else
    (void)threads;
#endif
    // don't add FFTW_WISDOM_ONLY if the plan rigor is FFTW_ESTIMATE
    // because FFTW_ESTIMATE guarantee to not destroy the input
    unsigned roflags = flags;
    if( ! (flags & FFTW_ESTIMATE) )
      {
      roflags = flags | FFTW_WISDOM_ONLY;
      }
    PlanType plan = fftwf_plan_dft_r2c(rank,n,in,out,roflags);
    if( plan == nullptr )
      {
      // no wisdom available for that plan
      if( canDestroyInput )
        {
        // just create the plan
        plan = fftwf_plan_dft_r2c(rank,n,in,out,flags);
        }
      else
        {
        // lets create a plan with a fake input to generate the wisdom
        int total = 1;
        for( int i=0; i<rank; i++ )
          {
          total *= n[i];
          }
        auto * din = new PixelType[total];
        fftwf_plan_dft_r2c(rank,n,din,out,flags);
        delete[] din;
        // and then create the final plan - this time it shouldn't fail
        plan = fftwf_plan_dft_r2c(rank,n,in,out,roflags);
        }
#ifndef ITK_USE_CUFFTW
      FFTWGlobalConfiguration::SetNewWisdomAvailable(true);
#endif
      }
    itkAssertOrThrowMacro( plan != nullptr , "PLAN_CREATION_FAILED ");
    return plan;
  }

  static PlanType Plan_dft_1d(int n,
                                  ComplexType *in,
                                  ComplexType *out,
                                  int sign,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    return Plan_dft(1, &n, in, out,sign , flags, threads, canDestroyInput);
  }

  static PlanType Plan_dft_2d(int nx,
                                  int ny,
                                  ComplexType *in,
                                  ComplexType *out,
                                  int sign,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[2];
    sizes[0] = nx;
    sizes[1] = ny;
    PlanType plan = Plan_dft(2, sizes, in, out, sign, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_3d(int nx,
                                  int ny,
                                  int nz,
                                  ComplexType *in,
                                  ComplexType *out,
                                  int sign,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[3];
    sizes[0] = nx;
    sizes[1] = ny;
    sizes[2] = nz;
    PlanType plan = Plan_dft(3, sizes, in, out, sign, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft(int rank,
                               const int *n,
                               ComplexType *in,
                               ComplexType *out,
                               int sign,
                               unsigned flags,
                               int threads=1,
                               bool canDestroyInput=false)
  {
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
    fftwf_plan_with_nthreads(threads);
#else
    (void)threads;
#endif
    // don't add FFTW_WISDOM_ONLY if the plan rigor is FFTW_ESTIMATE
    // because FFTW_ESTIMATE guarantee to not destroy the input
    unsigned roflags = flags;
    if( ! (flags & FFTW_ESTIMATE) )
      {
      roflags = flags | FFTW_WISDOM_ONLY;
      }
    PlanType plan = fftwf_plan_dft(rank,n,in,out,sign,roflags);
    if( plan == nullptr )
      {
      // no wisdom available for that plan
      if( canDestroyInput )
        {
        // just create the plan
        plan = fftwf_plan_dft(rank,n,in,out,sign,flags);
        }
      else
        {
        // lets create a plan with a fake input to generate the wisdom
        int total = 1;
        for( int i=0; i<rank; i++ )
          {
          total *= n[i];
          }
        auto * din = new ComplexType[total];
        fftwf_plan_dft(rank,n,din,out,sign,flags);
        delete[] din;
        // and then create the final plan - this time it shouldn't fail
        plan = fftwf_plan_dft(rank,n,in,out,sign,roflags);
        }
#ifndef ITK_USE_CUFFTW
      FFTWGlobalConfiguration::SetNewWisdomAvailable(true);
#endif
      }
    itkAssertOrThrowMacro( plan != nullptr , "PLAN_CREATION_FAILED ");
    return plan;
  }


  static void Execute(PlanType p)
  {
    fftwf_execute(p);
  }
  static void DestroyPlan(PlanType p)
  {
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
#endif
    fftwf_destroy_plan(p);
  }
};

#endif // ITK_USE_FFTWF


#if defined( ITK_USE_FFTWD )
template< >
class Proxy< double >
{
public:
  using PixelType = double;
  using ComplexType = fftw_complex;
  using PlanType = fftw_plan;
  using Self = Proxy<double>;

  // FFTW works with any data size, but is optimized for size decomposition with prime factors up to 13.
#ifdef ITK_USE_CUFFTW
  static constexpr SizeValueType GREATEST_PRIME_FACTOR = 7;
#else
  static constexpr SizeValueType GREATEST_PRIME_FACTOR = 13;
#endif

  static PlanType Plan_dft_c2r_1d(int n,
                                  ComplexType *in,
                                  PixelType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    return Plan_dft_c2r(1, &n, in, out, flags, threads, canDestroyInput);
  }

  static PlanType Plan_dft_c2r_2d(int nx,
                                  int ny,
                                  ComplexType *in,
                                  PixelType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[2];
    sizes[0] = nx;
    sizes[1] = ny;
    PlanType plan = Plan_dft_c2r(2, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_c2r_3d(int nx,
                                  int ny,
                                  int nz,
                                  ComplexType *in,
                                  PixelType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[3];
    sizes[0] = nx;
    sizes[1] = ny;
    sizes[2] = nz;
    PlanType plan = Plan_dft_c2r(3, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_c2r(int rank,
                               const int *n,
                               ComplexType *in,
                               PixelType *out,
                               unsigned flags,
                               int threads=1,
                               bool canDestroyInput=false)
  {
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
    fftw_plan_with_nthreads(threads);
#else
    (void)threads;
#endif
    // don't add FFTW_WISDOM_ONLY if the plan rigor is FFTW_ESTIMATE
    // because FFTW_ESTIMATE guarantee to not destroy the input
    unsigned roflags = flags;
    if( ! (flags & FFTW_ESTIMATE) )
      {
      roflags = flags | FFTW_WISDOM_ONLY;
      }
    PlanType plan = fftw_plan_dft_c2r(rank,n,in,out,roflags);
    if( plan == nullptr )
      {
      // no wisdom available for that plan
      if( canDestroyInput )
        {
        // just create the plan
        plan = fftw_plan_dft_c2r(rank,n,in,out,flags);
        }
      else
        {
        // lets create a plan with a fake input to generate the wisdom
        int total = 1;
        for( int i=0; i<rank; i++ )
          {
          total *= n[i];
          }
        auto * din = new ComplexType[total];
        fftw_plan_dft_c2r(rank,n,din,out,flags);
        delete[] din;
        // and then create the final plan - this time it shouldn't fail
        plan = fftw_plan_dft_c2r(rank,n,in,out,roflags);
        }
#ifndef ITK_USE_CUFFTW
      FFTWGlobalConfiguration::SetNewWisdomAvailable(true);
#endif
      }
    itkAssertOrThrowMacro( plan != nullptr , "PLAN_CREATION_FAILED ");
    return plan;
  }


  static PlanType Plan_dft_r2c_1d(int n,
                                  PixelType *in,
                                  ComplexType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    return Plan_dft_r2c(1, &n, in, out, flags, threads, canDestroyInput);
  }

  static PlanType Plan_dft_r2c_2d(int nx,
                                  int ny,
                                  PixelType *in,
                                  ComplexType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[2];
    sizes[0] = nx;
    sizes[1] = ny;
    PlanType plan = Plan_dft_r2c(2, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_r2c_3d(int nx,
                                  int ny,
                                  int nz,
                                  PixelType *in,
                                  ComplexType *out,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[3];
    sizes[0] = nx;
    sizes[1] = ny;
    sizes[2] = nz;
    PlanType plan = Plan_dft_r2c(3, sizes, in, out, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_r2c(int rank,
                               const int *n,
                               PixelType *in,
                               ComplexType *out,
                               unsigned flags,
                               int threads=1,
                               bool canDestroyInput=false)
  {
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
    fftw_plan_with_nthreads(threads);
#else
    (void)threads;
#endif
    // don't add FFTW_WISDOM_ONLY if the plan rigor is FFTW_ESTIMATE
    // because FFTW_ESTIMATE guarantee to not destroy the input
    unsigned roflags = flags;
    if( ! (flags & FFTW_ESTIMATE) )
      {
      roflags = flags | FFTW_WISDOM_ONLY;
      }
    PlanType plan = fftw_plan_dft_r2c(rank,n,in,out,roflags);
    if( plan == nullptr )
      {
      // no wisdom available for that plan
      if( canDestroyInput )
        {
        // just create the plan
        plan = fftw_plan_dft_r2c(rank,n,in,out,flags);
        }
      else
        {
        // lets create a plan with a fake input to generate the wisdom
        int total = 1;
        for( int i=0; i<rank; i++ )
          {
          total *= n[i];
          }
        auto * din = new PixelType[total];
        fftw_plan_dft_r2c(rank,n,din,out,flags);
        delete[] din;
        // and then create the final plan - this time it shouldn't fail
        plan = fftw_plan_dft_r2c(rank,n,in,out,roflags);
        }
#ifndef ITK_USE_CUFFTW
      FFTWGlobalConfiguration::SetNewWisdomAvailable(true);
#endif
      }
    itkAssertOrThrowMacro( plan != nullptr , "PLAN_CREATION_FAILED ");
    return plan;
  }

  static PlanType Plan_dft_1d(int n,
                                  ComplexType *in,
                                  ComplexType *out,
                                  int sign,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    return Plan_dft(1, &n, in, out,sign , flags, threads, canDestroyInput);
  }

  static PlanType Plan_dft_2d(int nx,
                                  int ny,
                                  ComplexType *in,
                                  ComplexType *out,
                                  int sign,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[2];
    sizes[0] = nx;
    sizes[1] = ny;
    PlanType plan = Plan_dft(2, sizes, in, out, sign, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft_3d(int nx,
                                  int ny,
                                  int nz,
                                  ComplexType *in,
                                  ComplexType *out,
                                  int sign,
                                  unsigned flags,
                                  int threads=1,
                                  bool canDestroyInput=false)
  {
    auto * sizes = new int[3];
    sizes[0] = nx;
    sizes[1] = ny;
    sizes[2] = nz;
    PlanType plan = Plan_dft(3, sizes, in, out, sign, flags, threads, canDestroyInput);
    delete[] sizes;
    return plan;
  }

  static PlanType Plan_dft(int rank,
                               const int *n,
                               ComplexType *in,
                               ComplexType *out,
                               int sign,
                               unsigned flags,
                               int threads=1,
                               bool canDestroyInput=false)
  {
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
    fftw_plan_with_nthreads(threads);
#else
    (void)threads;
#endif
    // don't add FFTW_WISDOM_ONLY if the plan rigor is FFTW_ESTIMATE
    // because FFTW_ESTIMATE guarantee to not destroy the input
    unsigned roflags = flags;
    if( ! (flags & FFTW_ESTIMATE) )
      {
      roflags = flags | FFTW_WISDOM_ONLY;
      }
    PlanType plan = fftw_plan_dft(rank,n,in,out,sign,roflags);
    if( plan == nullptr )
      {
      // no wisdom available for that plan
      if( canDestroyInput )
        {
        // just create the plan
        plan = fftw_plan_dft(rank,n,in,out,sign,flags);
        }
      else
        {
        // lets create a plan with a fake input to generate the wisdom
        int total = 1;
        for( int i=0; i<rank; i++ )
          {
          total *= n[i];
          }
        auto * din = new ComplexType[total];
        fftw_plan_dft(rank,n,din,out,sign,flags);
        delete[] din;
        // and then create the final plan - this time it shouldn't fail
        plan = fftw_plan_dft(rank,n,in,out,sign,roflags);
        }
#ifndef ITK_USE_CUFFTW
      FFTWGlobalConfiguration::SetNewWisdomAvailable(true);
#endif
      }
    itkAssertOrThrowMacro( plan != nullptr , "PLAN_CREATION_FAILED ");
    return plan;
  }


  static void Execute(PlanType p)
  {
    fftw_execute(p);
  }
  static void DestroyPlan(PlanType p)
  {
#ifndef ITK_USE_CUFFTW
    std::lock_guard< FFTWGlobalConfiguration::MutexType > lock( FFTWGlobalConfiguration::GetLockMutex() );
#endif
    fftw_destroy_plan(p);
  }
};

#endif
} // end namespace fftw
} // end namespace itk
#endif
