// SPDX-License-Identifier: Apache-2.0
//
// Copyright 2008-2016 Conrad Sanderson (http://conradsanderson.id.au)
// Copyright 2008-2016 National ICT Australia (NICTA)
//
// 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
//
// 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.
// ------------------------------------------------------------------------

//! \addtogroup op_sort_index
//! @{

class op_sort_index : public traits_op_col {
 public:
  template <typename T1>
  static inline bool apply_noalias(Mat<uword>& out, const Proxy<T1>& P,
                                   const uword sort_type);

  template <typename T1>
  static inline void apply(Mat<uword>& out, const mtOp<uword, T1, op_sort_index>& in);
};

class op_stable_sort_index : public traits_op_col {
 public:
  template <typename T1>
  static inline bool apply_noalias(Mat<uword>& out, const Proxy<T1>& P,
                                   const uword sort_type);

  template <typename T1>
  static inline void apply(Mat<uword>& out,
                           const mtOp<uword, T1, op_stable_sort_index>& in);
};

template <typename eT>
struct arma_sort_index_packet {
  eT val;
  uword index;
};

template <typename eT>
struct arma_sort_index_helper_ascend {
  arma_inline bool operator()(const arma_sort_index_packet<eT>& A,
                              const arma_sort_index_packet<eT>& B) const {
    return (A.val < B.val);
  }
};

template <typename eT>
struct arma_sort_index_helper_descend {
  arma_inline bool operator()(const arma_sort_index_packet<eT>& A,
                              const arma_sort_index_packet<eT>& B) const {
    return (A.val > B.val);
  }
};

template <typename T>
struct arma_sort_index_helper_ascend<std::complex<T> > {
  typedef typename std::complex<T> eT;

  inline bool operator()(const arma_sort_index_packet<eT>& A,
                         const arma_sort_index_packet<eT>& B) const {
    return (std::abs(A.val) < std::abs(B.val));
  }

  // inline
  // bool
  // operator() (const arma_sort_index_packet<eT>& A, const arma_sort_index_packet<eT>& B)
  // const
  //   {
  //   const T abs_A_val = std::abs(A.val);
  //   const T abs_B_val = std::abs(B.val);
  //
  //   return ( (abs_A_val != abs_B_val) ? (abs_A_val < abs_B_val) : (std::arg(A.val) <
  //   std::arg(B.val)) );
  //   }
};

template <typename T>
struct arma_sort_index_helper_descend<std::complex<T> > {
  typedef typename std::complex<T> eT;

  inline bool operator()(const arma_sort_index_packet<eT>& A,
                         const arma_sort_index_packet<eT>& B) const {
    return (std::abs(A.val) > std::abs(B.val));
  }

  // inline
  // bool
  // operator() (const arma_sort_index_packet<eT>& A, const arma_sort_index_packet<eT>& B)
  // const
  //   {
  //   const T abs_A_val = std::abs(A.val);
  //   const T abs_B_val = std::abs(B.val);
  //
  //   return ( (abs_A_val != abs_B_val) ? (abs_A_val > abs_B_val) : (std::arg(A.val) >
  //   std::arg(B.val)) );
  //   }
};

//! @}
