// 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_toeplitz
//! @{

template <typename T1>
inline void op_toeplitz::apply(Mat<typename T1::elem_type>& out,
                               const Op<T1, op_toeplitz>& in) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const unwrap_check<T1> tmp(in.m, out);
  const Mat<eT>& X = tmp.M;

  arma_conform_check(((X.is_vec() == false) && (X.is_empty() == false)),
                     "toeplitz(): given object must be a vector");

  const uword N = X.n_elem;
  const eT* X_mem = X.memptr();

  out.set_size(N, N);

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

    uword i;

    i = col;
    for (uword row = 0; row < col; ++row, --i) {
      col_mem[row] = X_mem[i];
    }

    i = 0;
    for (uword row = col; row < N; ++row, ++i) {
      col_mem[row] = X_mem[i];
    }
  }
}

template <typename T1>
inline void op_toeplitz_c::apply(Mat<typename T1::elem_type>& out,
                                 const Op<T1, op_toeplitz_c>& in) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const unwrap_check<T1> tmp(in.m, out);
  const Mat<eT>& X = tmp.M;

  arma_conform_check(((X.is_vec() == false) && (X.is_empty() == false)),
                     "circ_toeplitz(): given object must be a vector");

  const uword N = X.n_elem;
  const eT* X_mem = X.memptr();

  out.set_size(N, N);

  if (X.is_rowvec()) {
    for (uword row = 0; row < N; ++row) {
      uword i;

      i = row;
      for (uword col = 0; col < row; ++col, --i) {
        out.at(row, col) = X_mem[N - i];
      }

      i = 0;
      for (uword col = row; col < N; ++col, ++i) {
        out.at(row, col) = X_mem[i];
      }
    }
  } else {
    for (uword col = 0; col < N; ++col) {
      eT* col_mem = out.colptr(col);

      uword i;

      i = col;
      for (uword row = 0; row < col; ++row, --i) {
        col_mem[row] = X_mem[N - i];
      }

      i = 0;
      for (uword row = col; row < N; ++row, ++i) {
        col_mem[row] = X_mem[i];
      }
    }
  }
}

//! @}
