/*************************************************************************************

Grid physics library, www.github.com/paboyle/Grid

Source file: ./lib/lattice/Lattice_ET.h

Copyright (C) 2015

Author: Azusa Yamaguchi <ayamaguc@staffmail.ed.ac.uk>
Author: Peter Boyle <paboyle@ph.ed.ac.uk>
Author: neo <cossu@post.kek.jp>

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License along
with this program; if not, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

See the full license in the file "LICENSE" in the top level distribution
directory
*************************************************************************************/
/*  END LEGAL */
#ifndef GRID_LATTICE_ET_H
#define GRID_LATTICE_ET_H

#include <iostream>
#include <tuple>
#include <typeinfo>
#include <vector>

namespace Grid {

////////////////////////////////////////////////////
// Predicated where support
////////////////////////////////////////////////////
template <class iobj, class vobj, class robj>
inline vobj predicatedWhere(const iobj &predicate, const vobj &iftrue,
                            const robj &iffalse) {
  typename std::remove_const<vobj>::type ret;

  typedef typename vobj::scalar_object scalar_object;
  typedef typename vobj::scalar_type scalar_type;
  typedef typename vobj::vector_type vector_type;

  const int Nsimd = vobj::vector_type::Nsimd();
  const int words = sizeof(vobj) / sizeof(vector_type);

  std::vector<Integer> mask(Nsimd);
  std::vector<scalar_object> truevals(Nsimd);
  std::vector<scalar_object> falsevals(Nsimd);

  extract(iftrue, truevals);
  extract(iffalse, falsevals);
  extract<vInteger, Integer>(TensorRemove(predicate), mask);

  for (int s = 0; s < Nsimd; s++) {
    if (mask[s]) falsevals[s] = truevals[s];
  }

  merge(ret, falsevals);
  return ret;
}

////////////////////////////////////////////
// recursive evaluation of expressions; Could
// switch to generic approach with variadics, a la
// Antonin's Lat Sim but the repack to variadic with popped
// from tuple is hideous; C++14 introduces std::make_index_sequence for this
////////////////////////////////////////////

// leaf eval of lattice ; should enable if protect using traits

template <typename T>
using is_lattice = std::is_base_of<LatticeBase, T>;

template <typename T>
using is_lattice_expr = std::is_base_of<LatticeExpressionBase, T>;

template <class sobj>
inline sobj eval(const unsigned int ss, const sobj &arg) {
  return arg;
}
template <class lobj>
inline const lobj &eval(const unsigned int ss, const Lattice<lobj> &arg) {
  return arg._odata[ss];
}

// handle nodes in syntax tree
template <typename Op, typename T1>
auto inline eval(
    const unsigned int ss,
    const LatticeUnaryExpression<Op, T1> &expr)  // eval one operand
    -> decltype(expr.first.func(eval(ss, std::get<0>(expr.second)))) {
  return expr.first.func(eval(ss, std::get<0>(expr.second)));
}

template <typename Op, typename T1, typename T2>
auto inline eval(
    const unsigned int ss,
    const LatticeBinaryExpression<Op, T1, T2> &expr)  // eval two operands
    -> decltype(expr.first.func(eval(ss, std::get<0>(expr.second)),
                                eval(ss, std::get<1>(expr.second)))) {
  return expr.first.func(eval(ss, std::get<0>(expr.second)),
                         eval(ss, std::get<1>(expr.second)));
}

template <typename Op, typename T1, typename T2, typename T3>
auto inline eval(const unsigned int ss,
                 const LatticeTrinaryExpression<Op, T1, T2, T3>
                     &expr)  // eval three operands
    -> decltype(expr.first.func(eval(ss, std::get<0>(expr.second)),
                                eval(ss, std::get<1>(expr.second)),
                                eval(ss, std::get<2>(expr.second)))) {
  return expr.first.func(eval(ss, std::get<0>(expr.second)),
                         eval(ss, std::get<1>(expr.second)),
                         eval(ss, std::get<2>(expr.second)));
}

//////////////////////////////////////////////////////////////////////////
// Obtain the grid from an expression, ensuring conformable. This must follow a
// tree recursion
//////////////////////////////////////////////////////////////////////////
template <class T1,
          typename std::enable_if<is_lattice<T1>::value, T1>::type * = nullptr>
inline void GridFromExpression(GridBase *&grid, const T1 &lat)  // Lattice leaf
{
  if (grid) {
    conformable(grid, lat._grid);
  }
  grid = lat._grid;
}
template <class T1,
          typename std::enable_if<!is_lattice<T1>::value, T1>::type * = nullptr>
inline void GridFromExpression(GridBase *&grid,
                               const T1 &notlat)  // non-lattice leaf
{}
template <typename Op, typename T1>
inline void GridFromExpression(GridBase *&grid,
                               const LatticeUnaryExpression<Op, T1> &expr) {
  GridFromExpression(grid, std::get<0>(expr.second));  // recurse
}

template <typename Op, typename T1, typename T2>
inline void GridFromExpression(
    GridBase *&grid, const LatticeBinaryExpression<Op, T1, T2> &expr) {
  GridFromExpression(grid, std::get<0>(expr.second));  // recurse
  GridFromExpression(grid, std::get<1>(expr.second));
}
template <typename Op, typename T1, typename T2, typename T3>
inline void GridFromExpression(
    GridBase *&grid, const LatticeTrinaryExpression<Op, T1, T2, T3> &expr) {
  GridFromExpression(grid, std::get<0>(expr.second));  // recurse
  GridFromExpression(grid, std::get<1>(expr.second));
  GridFromExpression(grid, std::get<2>(expr.second));
}

//////////////////////////////////////////////////////////////////////////
// Obtain the CB from an expression, ensuring conformable. This must follow a
// tree recursion
//////////////////////////////////////////////////////////////////////////
template <class T1,
          typename std::enable_if<is_lattice<T1>::value, T1>::type * = nullptr>
inline void CBFromExpression(int &cb, const T1 &lat)  // Lattice leaf
{
  if ((cb == Odd) || (cb == Even)) {
    assert(cb == lat.checkerboard);
  }
  cb = lat.checkerboard;
  //  std::cout<<GridLogMessage<<"Lattice leaf cb "<<cb<<std::endl;
}
template <class T1,
          typename std::enable_if<!is_lattice<T1>::value, T1>::type * = nullptr>
inline void CBFromExpression(int &cb, const T1 &notlat)  // non-lattice leaf
{
  //  std::cout<<GridLogMessage<<"Non lattice leaf cb"<<cb<<std::endl;
}
template <typename Op, typename T1>
inline void CBFromExpression(int &cb,
                             const LatticeUnaryExpression<Op, T1> &expr) {
  CBFromExpression(cb, std::get<0>(expr.second));  // recurse
  //  std::cout<<GridLogMessage<<"Unary node cb "<<cb<<std::endl;
}

template <typename Op, typename T1, typename T2>
inline void CBFromExpression(int &cb,
                             const LatticeBinaryExpression<Op, T1, T2> &expr) {
  CBFromExpression(cb, std::get<0>(expr.second));  // recurse
  CBFromExpression(cb, std::get<1>(expr.second));
  //  std::cout<<GridLogMessage<<"Binary node cb "<<cb<<std::endl;
}
template <typename Op, typename T1, typename T2, typename T3>
inline void CBFromExpression(
    int &cb, const LatticeTrinaryExpression<Op, T1, T2, T3> &expr) {
  CBFromExpression(cb, std::get<0>(expr.second));  // recurse
  CBFromExpression(cb, std::get<1>(expr.second));
  CBFromExpression(cb, std::get<2>(expr.second));
  //  std::cout<<GridLogMessage<<"Trinary node cb "<<cb<<std::endl;
}

////////////////////////////////////////////
// Unary operators and funcs
////////////////////////////////////////////
#define GridUnopClass(name, ret)                                          \
  template <class arg>                                                    \
  struct name {                                                           \
    static auto inline func(const arg a) -> decltype(ret) { return ret; } \
  };

GridUnopClass(UnarySub, -a);
GridUnopClass(UnaryNot, Not(a));
GridUnopClass(UnaryAdj, adj(a));
GridUnopClass(UnaryConj, conjugate(a));
GridUnopClass(UnaryTrace, trace(a));
GridUnopClass(UnaryTranspose, transpose(a));
GridUnopClass(UnaryTa, Ta(a));
GridUnopClass(UnaryProjectOnGroup, ProjectOnGroup(a));
GridUnopClass(UnaryReal, real(a));
GridUnopClass(UnaryImag, imag(a));
GridUnopClass(UnaryToReal, toReal(a));
GridUnopClass(UnaryToComplex, toComplex(a));
GridUnopClass(UnaryTimesI, timesI(a));
GridUnopClass(UnaryTimesMinusI, timesMinusI(a));
GridUnopClass(UnaryAbs, abs(a));
GridUnopClass(UnarySqrt, sqrt(a));
GridUnopClass(UnaryRsqrt, rsqrt(a));
GridUnopClass(UnarySin, sin(a));
GridUnopClass(UnaryCos, cos(a));
GridUnopClass(UnaryAsin, asin(a));
GridUnopClass(UnaryAcos, acos(a));
GridUnopClass(UnaryLog, log(a));
GridUnopClass(UnaryExp, exp(a));

////////////////////////////////////////////
// Binary operators
////////////////////////////////////////////
#define GridBinOpClass(name, combination)                      \
  template <class left, class right>                           \
  struct name {                                                \
    static auto inline func(const left &lhs, const right &rhs) \
        -> decltype(combination) const {                       \
      return combination;                                      \
    }                                                          \
  }
GridBinOpClass(BinaryAdd, lhs + rhs);
GridBinOpClass(BinarySub, lhs - rhs);
GridBinOpClass(BinaryMul, lhs *rhs);

GridBinOpClass(BinaryAnd, lhs &rhs);
GridBinOpClass(BinaryOr, lhs | rhs);
GridBinOpClass(BinaryAndAnd, lhs &&rhs);
GridBinOpClass(BinaryOrOr, lhs || rhs);

////////////////////////////////////////////////////
// Trinary conditional op
////////////////////////////////////////////////////
#define GridTrinOpClass(name, combination)                                     \
  template <class predicate, class left, class right>                          \
  struct name {                                                                \
    static auto inline func(const predicate &pred, const left &lhs,            \
                            const right &rhs) -> decltype(combination) const { \
      return combination;                                                      \
    }                                                                          \
  }

GridTrinOpClass(
    TrinaryWhere,
    (predicatedWhere<predicate, typename std::remove_reference<left>::type,
                     typename std::remove_reference<right>::type>(pred, lhs,
                                                                  rhs)));

////////////////////////////////////////////
// Operator syntactical glue
////////////////////////////////////////////

#define GRID_UNOP(name) name<decltype(eval(0, arg))>
#define GRID_BINOP(name) name<decltype(eval(0, lhs)), decltype(eval(0, rhs))>
#define GRID_TRINOP(name) \
  name<decltype(eval(0, pred)), decltype(eval(0, lhs)), decltype(eval(0, rhs))>

#define GRID_DEF_UNOP(op, name)                                             \
  template <typename T1,                                                    \
            typename std::enable_if<is_lattice<T1>::value ||                \
                                        is_lattice_expr<T1>::value,         \
                                    T1>::type * = nullptr>                  \
  inline auto op(const T1 &arg)                                             \
      ->decltype(LatticeUnaryExpression<GRID_UNOP(name), const T1 &>(       \
          std::make_pair(GRID_UNOP(name)(), std::forward_as_tuple(arg)))) { \
    return LatticeUnaryExpression<GRID_UNOP(name), const T1 &>(             \
        std::make_pair(GRID_UNOP(name)(), std::forward_as_tuple(arg)));     \
  }

#define GRID_BINOP_LEFT(op, name)                                             \
  template <typename T1, typename T2,                                         \
            typename std::enable_if<is_lattice<T1>::value ||                  \
                                        is_lattice_expr<T1>::value,           \
                                    T1>::type * = nullptr>                    \
  inline auto op(const T1 &lhs, const T2 &rhs)                                \
      ->decltype(                                                             \
          LatticeBinaryExpression<GRID_BINOP(name), const T1 &, const T2 &>(  \
              std::make_pair(GRID_BINOP(name)(),                              \
                             std::forward_as_tuple(lhs, rhs)))) {             \
    return LatticeBinaryExpression<GRID_BINOP(name), const T1 &, const T2 &>( \
        std::make_pair(GRID_BINOP(name)(), std::forward_as_tuple(lhs, rhs))); \
  }

#define GRID_BINOP_RIGHT(op, name)                                            \
  template <typename T1, typename T2,                                         \
            typename std::enable_if<!is_lattice<T1>::value &&                 \
                                        !is_lattice_expr<T1>::value,          \
                                    T1>::type * = nullptr,                    \
            typename std::enable_if<is_lattice<T2>::value ||                  \
                                        is_lattice_expr<T2>::value,           \
                                    T2>::type * = nullptr>                    \
  inline auto op(const T1 &lhs, const T2 &rhs)                                \
      ->decltype(                                                             \
          LatticeBinaryExpression<GRID_BINOP(name), const T1 &, const T2 &>(  \
              std::make_pair(GRID_BINOP(name)(),                              \
                             std::forward_as_tuple(lhs, rhs)))) {             \
    return LatticeBinaryExpression<GRID_BINOP(name), const T1 &, const T2 &>( \
        std::make_pair(GRID_BINOP(name)(), std::forward_as_tuple(lhs, rhs))); \
  }

#define GRID_DEF_BINOP(op, name) \
  GRID_BINOP_LEFT(op, name);     \
  GRID_BINOP_RIGHT(op, name);

#define GRID_DEF_TRINOP(op, name)                                              \
  template <typename T1, typename T2, typename T3>                             \
  inline auto op(const T1 &pred, const T2 &lhs, const T3 &rhs)                 \
      ->decltype(                                                              \
          LatticeTrinaryExpression<GRID_TRINOP(name), const T1 &, const T2 &,  \
                                   const T3 &>(std::make_pair(                 \
              GRID_TRINOP(name)(), std::forward_as_tuple(pred, lhs, rhs)))) {  \
    return LatticeTrinaryExpression<GRID_TRINOP(name), const T1 &, const T2 &, \
                                    const T3 &>(std::make_pair(                \
        GRID_TRINOP(name)(), std::forward_as_tuple(pred, lhs, rhs)));          \
  }
////////////////////////
// Operator definitions
////////////////////////

GRID_DEF_UNOP(operator-, UnarySub);
GRID_DEF_UNOP(Not, UnaryNot);
GRID_DEF_UNOP(operator!, UnaryNot);
GRID_DEF_UNOP(adj, UnaryAdj);
GRID_DEF_UNOP(conjugate, UnaryConj);
GRID_DEF_UNOP(trace, UnaryTrace);
GRID_DEF_UNOP(transpose, UnaryTranspose);
GRID_DEF_UNOP(Ta, UnaryTa);
GRID_DEF_UNOP(ProjectOnGroup, UnaryProjectOnGroup);
GRID_DEF_UNOP(real, UnaryReal);
GRID_DEF_UNOP(imag, UnaryImag);
GRID_DEF_UNOP(toReal, UnaryToReal);
GRID_DEF_UNOP(toComplex, UnaryToComplex);
GRID_DEF_UNOP(timesI, UnaryTimesI);
GRID_DEF_UNOP(timesMinusI, UnaryTimesMinusI);
GRID_DEF_UNOP(abs, UnaryAbs);  // abs overloaded in cmath C++98; DON'T do the
                               // abs-fabs-dabs-labs thing
GRID_DEF_UNOP(sqrt, UnarySqrt);
GRID_DEF_UNOP(rsqrt, UnaryRsqrt);
GRID_DEF_UNOP(sin, UnarySin);
GRID_DEF_UNOP(cos, UnaryCos);
GRID_DEF_UNOP(asin, UnaryAsin);
GRID_DEF_UNOP(acos, UnaryAcos);
GRID_DEF_UNOP(log, UnaryLog);
GRID_DEF_UNOP(exp, UnaryExp);

GRID_DEF_BINOP(operator+, BinaryAdd);
GRID_DEF_BINOP(operator-, BinarySub);
GRID_DEF_BINOP(operator*, BinaryMul);

GRID_DEF_BINOP(operator&, BinaryAnd);
GRID_DEF_BINOP(operator|, BinaryOr);
GRID_DEF_BINOP(operator&&, BinaryAndAnd);
GRID_DEF_BINOP(operator||, BinaryOrOr);

GRID_DEF_TRINOP(where, TrinaryWhere);

/////////////////////////////////////////////////////////////
// Closure convenience to force expression to evaluate
/////////////////////////////////////////////////////////////
template <class Op, class T1>
auto closure(const LatticeUnaryExpression<Op, T1> &expr)
    -> Lattice<decltype(expr.first.func(eval(0, std::get<0>(expr.second))))> {
  Lattice<decltype(expr.first.func(eval(0, std::get<0>(expr.second))))> ret(
      expr);
  return ret;
}
template <class Op, class T1, class T2>
auto closure(const LatticeBinaryExpression<Op, T1, T2> &expr)
    -> Lattice<decltype(expr.first.func(eval(0, std::get<0>(expr.second)),
                                        eval(0, std::get<1>(expr.second))))> {
  Lattice<decltype(expr.first.func(eval(0, std::get<0>(expr.second)),
                                   eval(0, std::get<1>(expr.second))))>
      ret(expr);
  return ret;
}
template <class Op, class T1, class T2, class T3>
auto closure(const LatticeTrinaryExpression<Op, T1, T2, T3> &expr)
    -> Lattice<decltype(expr.first.func(eval(0, std::get<0>(expr.second)),
                                        eval(0, std::get<1>(expr.second)),
                                        eval(0, std::get<2>(expr.second))))> {
  Lattice<decltype(expr.first.func(eval(0, std::get<0>(expr.second)),
                                   eval(0, std::get<1>(expr.second)),
                                   eval(0, std::get<2>(expr.second))))>
      ret(expr);
  return ret;
}

#undef GRID_UNOP
#undef GRID_BINOP
#undef GRID_TRINOP

#undef GRID_DEF_UNOP
#undef GRID_DEF_BINOP
#undef GRID_DEF_TRINOP
}

#if 0
using namespace Grid;
        
 int main(int argc,char **argv){
   
   Lattice<double> v1(16);
   Lattice<double> v2(16);
   Lattice<double> v3(16);

   BinaryAdd<double,double> tmp;
   LatticeBinaryExpression<BinaryAdd<double,double>,Lattice<double> &,Lattice<double> &> 
     expr(std::make_pair(tmp,
    std::forward_as_tuple(v1,v2)));
   tmp.func(eval(0,v1),eval(0,v2));

   auto var = v1+v2;
   std::cout<<GridLogMessage<<typeid(var).name()<<std::endl;

   v3=v1+v2;
   v3=v1+v2+v1*v2;
 };

void testit(Lattice<double> &v1,Lattice<double> &v2,Lattice<double> &v3)
{
   v3=v1+v2+v1*v2;
}
#endif

#endif