// 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 fn_shift
//! @{

template <typename T1>
arma_warn_unused arma_inline
    typename enable_if2<is_arma_type<T1>::value && resolves_to_vector<T1>::yes,
                        const Op<T1, op_shift_vec> >::result
    shift(const T1& X, const sword N) {
  arma_debug_sigprint();

  const uword len = (N < 0) ? uword(-N) : uword(N);
  const uword neg = (N < 0) ? uword(1) : uword(0);

  return Op<T1, op_shift_vec>(X, len, neg);
}

template <typename T1>
arma_warn_unused inline
    typename enable_if2<is_arma_type<T1>::value && resolves_to_vector<T1>::no,
                        Mat<typename T1::elem_type> >::result
    shift(const T1& X, const sword N) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const uword len = (N < 0) ? uword(-N) : uword(N);
  const uword neg = (N < 0) ? uword(1) : uword(0);

  quasi_unwrap<T1> U(X);

  Mat<eT> out;

  op_shift::apply_noalias(out, U.M, len, neg, 0);

  return out;
}

template <typename T1>
arma_warn_unused inline
    typename enable_if2<(is_arma_type<T1>::value), Mat<typename T1::elem_type> >::result
    shift(const T1& X, const sword N, const uword dim) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  arma_conform_check((dim > 1), "shift(): parameter 'dim' must be 0 or 1");

  const uword len = (N < 0) ? uword(-N) : uword(N);
  const uword neg = (N < 0) ? uword(1) : uword(0);

  quasi_unwrap<T1> U(X);

  Mat<eT> out;

  op_shift::apply_noalias(out, U.M, len, neg, dim);

  return out;
}

//

template <typename T1>
arma_warn_unused inline SpMat<typename T1::elem_type> shift(
    const SpBase<typename T1::elem_type, T1>& expr, const sword N, const uword dim = 0) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  arma_conform_check((dim > 1), "shift(): parameter 'dim' must be 0 or 1");

  const uword len = (N < 0) ? uword(-N) : uword(N);
  const uword neg = (N < 0) ? uword(1) : uword(0);

  unwrap_spmat<T1> U(expr.get_ref());

  SpMat<eT> out;

  spop_shift::apply_noalias(out, U.M, len, neg, dim);

  return out;
}

//! @}
