#include <Grid.h>

namespace Grid {
namespace QCD {
  
// S-direction is INNERMOST and takes no part in the parity.
const std::vector<int> WilsonFermion5DStatic::directions   ({1,2,3,4, 1, 2, 3, 4});
const std::vector<int> WilsonFermion5DStatic::displacements({1,1,1,1,-1,-1,-1,-1});
int WilsonFermion5DStatic::HandOptDslash;

  // 5d lattice for DWF.
template<class Impl>
WilsonFermion5D<Impl>::WilsonFermion5D(GaugeField &_Umu,
				       GridCartesian         &FiveDimGrid,
				       GridRedBlackCartesian &FiveDimRedBlackGrid,
				       GridCartesian         &FourDimGrid,
				       GridRedBlackCartesian &FourDimRedBlackGrid,
				       RealD _M5) :
  _FiveDimGrid(&FiveDimGrid),
  _FiveDimRedBlackGrid(&FiveDimRedBlackGrid),
  _FourDimGrid(&FourDimGrid),
  _FourDimRedBlackGrid(&FourDimRedBlackGrid),
  Stencil    (_FiveDimGrid,npoint,Even,directions,displacements),
  StencilEven(_FiveDimRedBlackGrid,npoint,Even,directions,displacements), // source is Even
  StencilOdd (_FiveDimRedBlackGrid,npoint,Odd ,directions,displacements), // source is Odd
  M5(_M5),
  Umu(_FourDimGrid),
  UmuEven(_FourDimRedBlackGrid),
  UmuOdd (_FourDimRedBlackGrid),
  Lebesgue(_FourDimGrid),
  LebesgueEvenOdd(_FourDimRedBlackGrid)
{
  // some assertions
  assert(FiveDimGrid._ndimension==5);
  assert(FourDimGrid._ndimension==4);
  
  assert(FiveDimRedBlackGrid._ndimension==5);
  assert(FourDimRedBlackGrid._ndimension==4);

  assert(FiveDimRedBlackGrid._checker_dim==1);

  // Dimension zero of the five-d is the Ls direction
  Ls=FiveDimGrid._fdimensions[0];
  assert(FiveDimRedBlackGrid._fdimensions[0]==Ls);
  assert(FiveDimRedBlackGrid._processors[0] ==1);
  assert(FiveDimRedBlackGrid._simd_layout[0]==1);
  assert(FiveDimGrid._processors[0]         ==1);
  assert(FiveDimGrid._simd_layout[0]        ==1);

  // Other dimensions must match the decomposition of the four-D fields 
  for(int d=0;d<4;d++){
    assert(FourDimRedBlackGrid._fdimensions[d]  ==FourDimGrid._fdimensions[d]);
    assert(FiveDimRedBlackGrid._fdimensions[d+1]==FourDimGrid._fdimensions[d]);

    assert(FourDimRedBlackGrid._processors[d]   ==FourDimGrid._processors[d]);
    assert(FiveDimRedBlackGrid._processors[d+1] ==FourDimGrid._processors[d]);

    assert(FourDimRedBlackGrid._simd_layout[d]  ==FourDimGrid._simd_layout[d]);
    assert(FiveDimRedBlackGrid._simd_layout[d+1]==FourDimGrid._simd_layout[d]);

    assert(FiveDimGrid._fdimensions[d+1]        ==FourDimGrid._fdimensions[d]);
    assert(FiveDimGrid._processors[d+1]         ==FourDimGrid._processors[d]);
    assert(FiveDimGrid._simd_layout[d+1]        ==FourDimGrid._simd_layout[d]);
  }

  // Allocate the required comms buffer
  comm_buf.resize(Stencil._unified_buffer_size); // this is always big enough to contain EO

  ImportGauge(_Umu);
}  
template<class Impl>
void WilsonFermion5D<Impl>::ImportGauge(const GaugeField &_Umu)
{
  Impl::DoubleStore(GaugeGrid(),Umu,_Umu);
  pickCheckerboard(Even,UmuEven,Umu);
  pickCheckerboard(Odd ,UmuOdd,Umu);
}
template<class Impl>
void WilsonFermion5D<Impl>::DhopDir(const FermionField &in, FermionField &out,int dir5,int disp)
{
  int dir = dir5-1; // Maps to the ordering above in "directions" that is passed to stencil
                    // we drop off the innermost fifth dimension
  //  assert( (disp==1)||(disp==-1) );
  //  assert( (dir>=0)&&(dir<4) ); //must do x,y,z or t;

  Compressor compressor(DaggerNo);
  Stencil.HaloExchange<SiteSpinor,SiteHalfSpinor,Compressor>(in,comm_buf,compressor);
  
  int skip = (disp==1) ? 0 : 1;

  int dirdisp = dir+skip*4;

  assert(dirdisp<=7);
  assert(dirdisp>=0);

PARALLEL_FOR_LOOP
  for(int ss=0;ss<Umu._grid->oSites();ss++){
    for(int s=0;s<Ls;s++){
      int sU=ss;
      int sF = s+Ls*sU; 
      Kernels::DiracOptDhopDir(Stencil,Umu,comm_buf,sF,sU,in,out,dirdisp,dirdisp);
    }
  }
};

template<class Impl>
void WilsonFermion5D<Impl>::DerivInternal(CartesianStencil & st,
				    DoubledGaugeField & U,
				    GaugeField &mat,
				    const FermionField &A,
				    const FermionField &B,
				    int dag)
{
  assert((dag==DaggerNo) ||(dag==DaggerYes));

  conformable(st._grid,A._grid);
  conformable(st._grid,B._grid);

  Compressor compressor(dag);
  
  GaugeLinkField tmp(mat._grid);
  FermionField Btilde(B._grid);
  FermionField Atilde(B._grid);

  st.HaloExchange<SiteSpinor,SiteHalfSpinor,Compressor>(B,comm_buf,compressor);

  Atilde=A;

  for(int mu=0;mu<Nd;mu++){
      
    ////////////////////////////////////////////////////////////////////////
    // Flip gamma if dag
    ////////////////////////////////////////////////////////////////////////
    int gamma = mu;
    if ( dag ) gamma+= Nd;

    ////////////////////////
    // Call the single hop
    ////////////////////////

PARALLEL_FOR_LOOP
    for(int sss=0;sss<U._grid->oSites();sss++){
      for(int s=0;s<Ls;s++){
	int sU=sss;
	int sF = s+Ls*sU;

	assert ( sF< B._grid->oSites());
	assert ( sU< U._grid->oSites());

	Kernels::DiracOptDhopDir(st,U,comm_buf,sF,sU,B,Btilde,mu,gamma);

    ////////////////////////////
    // spin trace outer product
    ////////////////////////////

      }

    }

    Impl::InsertForce(mat,Btilde,A,mu);
    /*
    tmp = zero;
    for(int sss=0;sss<U._grid->oSites();sss++){
      tmp[sU] = tmp[sU]+ traceIndex<SpinIndex>(outerProduct(Btilde[sF],Atilde[sF])); // ordering here
    }
    PokeIndex<LorentzIndex>(mat,tmp,mu);
    */

  }
}

template<class Impl>
void WilsonFermion5D<Impl>::DhopDeriv(      GaugeField &mat,
					    const FermionField &A,
					    const FermionField &B,
					    int dag)
{
  conformable(A._grid,FermionGrid());  
  conformable(A._grid,B._grid);
  conformable(GaugeGrid(),mat._grid);

  mat.checkerboard = A.checkerboard;

  DerivInternal(Stencil,Umu,mat,A,B,dag);
}

template<class Impl>
void WilsonFermion5D<Impl>::DhopDerivEO(GaugeField &mat,
					const FermionField &A,
					const FermionField &B,
					int dag)
{
  conformable(A._grid,FermionRedBlackGrid());
  conformable(GaugeRedBlackGrid(),mat._grid);
  conformable(A._grid,B._grid);

  assert(B.checkerboard==Odd);
  assert(A.checkerboard==Even);
  mat.checkerboard = Even;

  DerivInternal(StencilOdd,UmuEven,mat,A,B,dag);
}

template<class Impl>
void WilsonFermion5D<Impl>::DhopDerivOE(GaugeField &mat,
				  const FermionField &A,
				  const FermionField &B,
				  int dag)
{
  conformable(A._grid,FermionRedBlackGrid());
  conformable(GaugeRedBlackGrid(),mat._grid);
  conformable(A._grid,B._grid);

  assert(B.checkerboard==Even);
  assert(A.checkerboard==Odd);
  mat.checkerboard = Odd;

  DerivInternal(StencilEven,UmuOdd,mat,A,B,dag);
}

template<class Impl>
void WilsonFermion5D<Impl>::DhopInternal(CartesianStencil & st, LebesgueOrder &lo,
					 DoubledGaugeField & U,
					 const FermionField &in, FermionField &out,int dag)
{
  //  assert((dag==DaggerNo) ||(dag==DaggerYes));

  Compressor compressor(dag);

  st.HaloExchange<SiteSpinor,SiteHalfSpinor,Compressor>(in,comm_buf,compressor);
  
  // Dhop takes the 4d grid from U, and makes a 5d index for fermion
  // Not loop ordering and data layout.
  // Designed to create 
  // - per thread reuse in L1 cache for U
  // - 8 linear access unit stride streams per thread for Fermion for hw prefetchable.
  if ( dag == DaggerYes ) {
    if( this->HandOptDslash ) {
PARALLEL_FOR_LOOP
      for(int ss=0;ss<U._grid->oSites();ss++){
	for(int s=0;s<Ls;s++){
	  int sU=ss;
	  int sF = s+Ls*sU;
	  Kernels::DiracOptHandDhopSiteDag(st,U,comm_buf,sF,sU,in,out);
	  }
      }
    } else { 
PARALLEL_FOR_LOOP
      for(int ss=0;ss<U._grid->oSites();ss++){
	{
	  int sd;
	  for(sd=0;sd<Ls;sd++){
	    int sU=ss;
	    int sF = sd+Ls*sU;
	    Kernels::DiracOptDhopSiteDag(st,U,comm_buf,sF,sU,in,out);
	  }
	}
      }
    }
  } else {
    if( this->HandOptDslash ) {
PARALLEL_FOR_LOOP
      for(int ss=0;ss<U._grid->oSites();ss++){
	for(int s=0;s<Ls;s++){
	  //	  int sU=lo.Reorder(ss);
	  int sU=ss;
	  int sF = s+Ls*sU;
	  Kernels::DiracOptHandDhopSite(st,U,comm_buf,sF,sU,in,out);
	}
      }

    } else { 
PARALLEL_FOR_LOOP
      for(int ss=0;ss<U._grid->oSites();ss++){
	for(int s=0;s<Ls;s++){
	  //	  int sU=lo.Reorder(ss);
	  int sU=ss;
	  int sF = s+Ls*sU; 
	  Kernels::DiracOptDhopSite(st,U,comm_buf,sF,sU,in,out);
	}
      }
    }
  }
}
template<class Impl>
void WilsonFermion5D<Impl>::DhopOE(const FermionField &in, FermionField &out,int dag)
{
  conformable(in._grid,FermionRedBlackGrid());    // verifies half grid
  conformable(in._grid,out._grid); // drops the cb check

  assert(in.checkerboard==Even);
  out.checkerboard = Odd;

  DhopInternal(StencilEven,LebesgueEvenOdd,UmuOdd,in,out,dag);
}
template<class Impl>
void WilsonFermion5D<Impl>::DhopEO(const FermionField &in, FermionField &out,int dag)
{
  conformable(in._grid,FermionRedBlackGrid());    // verifies half grid
  conformable(in._grid,out._grid); // drops the cb check

  assert(in.checkerboard==Odd);
  out.checkerboard = Even;

  DhopInternal(StencilOdd,LebesgueEvenOdd,UmuEven,in,out,dag);
}
template<class Impl>
void WilsonFermion5D<Impl>::Dhop(const FermionField &in, FermionField &out,int dag)
{
  conformable(in._grid,FermionGrid()); // verifies full grid
  conformable(in._grid,out._grid);

  out.checkerboard = in.checkerboard;

  DhopInternal(Stencil,Lebesgue,Umu,in,out,dag);
}
template<class Impl>
void WilsonFermion5D<Impl>::DW(const FermionField &in, FermionField &out,int dag)
{
  out.checkerboard=in.checkerboard;
  Dhop(in,out,dag); // -0.5 is included
  axpy(out,4.0-M5,in,out);
}

FermOpTemplateInstantiate(WilsonFermion5D);

}}