// 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_htrans
//! @{

template <typename eT>
inline void op_htrans::apply_mat_noalias(Mat<eT>& out, const Mat<eT>& A,
                                         const typename arma_not_cx<eT>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  op_strans::apply_mat_noalias(out, A);
}

template <typename eT>
inline void op_htrans::apply_mat_noalias(Mat<eT>& out, const Mat<eT>& A,
                                         const typename arma_cx_only<eT>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  const uword A_n_rows = A.n_rows;
  const uword A_n_cols = A.n_cols;

  out.set_size(A_n_cols, A_n_rows);

  if ((A_n_cols == 1) || (A_n_rows == 1)) {
    const uword n_elem = A.n_elem;

    const eT* A_mem = A.memptr();
    eT* out_mem = out.memptr();

    for (uword i = 0; i < n_elem; ++i) {
      out_mem[i] = std::conj(A_mem[i]);
    }
  } else if ((A_n_rows >= 512) && (A_n_cols >= 512)) {
    op_htrans::apply_mat_noalias_large(out, A);
  } else {
    eT* outptr = out.memptr();

    for (uword k = 0; k < A_n_rows; ++k) {
      const eT* Aptr = &(A.at(k, 0));

      for (uword j = 0; j < A_n_cols; ++j) {
        (*outptr) = std::conj(*Aptr);

        Aptr += A_n_rows;
        outptr++;
      }
    }
  }
}

template <typename T>
inline void op_htrans::block_worker(std::complex<T>* Y, const std::complex<T>* X,
                                    const uword X_n_rows, const uword Y_n_rows,
                                    const uword n_rows, const uword n_cols) {
  for (uword row = 0; row < n_rows; ++row) {
    const uword Y_offset = row * Y_n_rows;

    for (uword col = 0; col < n_cols; ++col) {
      const uword X_offset = col * X_n_rows;

      Y[col + Y_offset] = std::conj(X[row + X_offset]);
    }
  }
}

template <typename T>
inline void op_htrans::apply_mat_noalias_large(Mat<std::complex<T> >& out,
                                               const Mat<std::complex<T> >& A) {
  arma_debug_sigprint();

  const uword n_rows = A.n_rows;
  const uword n_cols = A.n_cols;

  const uword block_size = 64;

  const uword n_rows_base = block_size * (n_rows / block_size);
  const uword n_cols_base = block_size * (n_cols / block_size);

  const uword n_rows_extra = n_rows - n_rows_base;
  const uword n_cols_extra = n_cols - n_cols_base;

  const std::complex<T>* X = A.memptr();
  std::complex<T>* Y = out.memptr();

  for (uword row = 0; row < n_rows_base; row += block_size) {
    const uword Y_offset = row * n_cols;

    for (uword col = 0; col < n_cols_base; col += block_size) {
      const uword X_offset = col * n_rows;

      op_htrans::block_worker(&Y[col + Y_offset], &X[row + X_offset], n_rows, n_cols,
                              block_size, block_size);
    }

    const uword X_offset = n_cols_base * n_rows;

    op_htrans::block_worker(&Y[n_cols_base + Y_offset], &X[row + X_offset], n_rows,
                            n_cols, block_size, n_cols_extra);
  }

  if (n_rows_extra == 0) {
    return;
  }

  const uword Y_offset = n_rows_base * n_cols;

  for (uword col = 0; col < n_cols_base; col += block_size) {
    const uword X_offset = col * n_rows;

    op_htrans::block_worker(&Y[col + Y_offset], &X[n_rows_base + X_offset], n_rows,
                            n_cols, n_rows_extra, block_size);
  }

  const uword X_offset = n_cols_base * n_rows;

  op_htrans::block_worker(&Y[n_cols_base + Y_offset], &X[n_rows_base + X_offset], n_rows,
                          n_cols, n_rows_extra, n_cols_extra);
}

template <typename eT>
inline void op_htrans::apply_mat_inplace(Mat<eT>& out,
                                         const typename arma_not_cx<eT>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  op_strans::apply_mat_inplace(out);
}

template <typename eT>
inline void op_htrans::apply_mat_inplace(Mat<eT>& out,
                                         const typename arma_cx_only<eT>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  const uword n_rows = out.n_rows;
  const uword n_cols = out.n_cols;

  if (n_rows == n_cols) {
    arma_debug_print("doing in-place hermitian transpose of a square matrix");

    for (uword col = 0; col < n_cols; ++col) {
      eT* coldata = out.colptr(col);

      out.at(col, col) = std::conj(out.at(col, col));

      for (uword row = (col + 1); row < n_rows; ++row) {
        const eT val1 = std::conj(coldata[row]);
        const eT val2 = std::conj(out.at(col, row));

        out.at(col, row) = val1;
        coldata[row] = val2;
      }
    }
  } else {
    Mat<eT> tmp;

    op_htrans::apply_mat_noalias(tmp, out);

    out.steal_mem(tmp);
  }
}

template <typename eT>
inline void op_htrans::apply_mat(Mat<eT>& out, const Mat<eT>& A,
                                 const typename arma_not_cx<eT>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  op_strans::apply_mat(out, A);
}

template <typename eT>
inline void op_htrans::apply_mat(Mat<eT>& out, const Mat<eT>& A,
                                 const typename arma_cx_only<eT>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  if (&out != &A) {
    op_htrans::apply_mat_noalias(out, A);
  } else {
    op_htrans::apply_mat_inplace(out);
  }
}

template <typename T1>
inline void op_htrans::apply_proxy(Mat<typename T1::elem_type>& out, const Proxy<T1>& P) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const uword n_rows = P.get_n_rows();
  const uword n_cols = P.get_n_cols();

  if ((resolves_to_vector<T1>::yes) && (Proxy<T1>::use_at == false)) {
    out.set_size(n_cols, n_rows);

    eT* out_mem = out.memptr();

    const uword n_elem = P.get_n_elem();

    typename Proxy<T1>::ea_type Pea = P.get_ea();

    for (uword i = 0; i < n_elem; ++i) {
      out_mem[i] = std::conj(Pea[i]);
    }
  } else {
    out.set_size(n_cols, n_rows);

    eT* outptr = out.memptr();

    for (uword k = 0; k < n_rows; ++k) {
      for (uword j = 0; j < n_cols; ++j) {
        (*outptr) = std::conj(P.at(k, j));

        outptr++;
      }
    }
  }
}

template <typename T1>
inline void op_htrans::apply_direct(Mat<typename T1::elem_type>& out, const T1& X) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  // allow detection of in-place transpose
  if (is_Mat<T1>::value || (arma_config::openmp && Proxy<T1>::use_mp)) {
    const unwrap<T1> U(X);

    op_htrans::apply_mat(out, U.M);
  } else {
    const Proxy<T1> P(X);

    const bool is_alias = P.is_alias(out);

    if (is_Mat<typename Proxy<T1>::stored_type>::value) {
      const quasi_unwrap<typename Proxy<T1>::stored_type> U(P.Q);

      if (is_alias) {
        Mat<eT> tmp;

        op_htrans::apply_mat_noalias(tmp, U.M);

        out.steal_mem(tmp);
      } else {
        op_htrans::apply_mat_noalias(out, U.M);
      }
    } else {
      if (is_alias) {
        Mat<eT> tmp;

        op_htrans::apply_proxy(tmp, P);

        out.steal_mem(tmp);
      } else {
        op_htrans::apply_proxy(out, P);
      }
    }
  }
}

template <typename T1>
inline void op_htrans::apply(
    Mat<typename T1::elem_type>& out, const Op<T1, op_htrans>& in,
    const typename arma_not_cx<typename T1::elem_type>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  op_strans::apply_direct(out, in.m);
}

template <typename T1>
inline void op_htrans::apply(
    Mat<typename T1::elem_type>& out, const Op<T1, op_htrans>& in,
    const typename arma_cx_only<typename T1::elem_type>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  op_htrans::apply_direct(out, in.m);
}

//
// op_htrans2

template <typename T1>
inline void op_htrans2::apply(
    Mat<typename T1::elem_type>& out, const Op<T1, op_htrans2>& in,
    const typename arma_not_cx<typename T1::elem_type>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  op_strans::apply_direct(out, in.m);

  arrayops::inplace_mul(out.memptr(), in.aux, out.n_elem);
}

template <typename T1>
inline void op_htrans2::apply(
    Mat<typename T1::elem_type>& out, const Op<T1, op_htrans2>& in,
    const typename arma_cx_only<typename T1::elem_type>::result* junk) {
  arma_debug_sigprint();
  arma_ignore(junk);

  op_htrans::apply_direct(out, in.m);

  arrayops::inplace_mul(out.memptr(), in.aux, out.n_elem);
}

//! @}
