// 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_pinv
//! @{

template <typename T1>
arma_warn_unused inline typename enable_if2<is_real<typename T1::pod_type>::value,
                                            const Op<T1, op_pinv_default> >::result
pinv(const Base<typename T1::elem_type, T1>& X) {
  arma_extra_debug_sigprint();

  return Op<T1, op_pinv_default>(X.get_ref());
}

template <typename T1>
arma_warn_unused inline typename enable_if2<is_real<typename T1::pod_type>::value,
                                            const Op<T1, op_pinv> >::result
pinv(const Base<typename T1::elem_type, T1>& X, const typename T1::pod_type tol,
     const char* method = nullptr) {
  arma_extra_debug_sigprint();

  typedef typename T1::elem_type eT;

  uword method_id = 0;  // default setting

  if (method != nullptr) {
    const char sig = method[0];

    arma_debug_check(((sig != 's') && (sig != 'd')), "pinv(): unknown method specified");

    if (sig == 's') {
      method_id = 1;
    }
    if (sig == 'd') {
      method_id = 2;
    }
  }

  return Op<T1, op_pinv>(X.get_ref(), eT(tol), method_id, uword(0));
}

template <typename T1>
inline typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result pinv(
    Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type, T1>& X,
    const typename T1::pod_type tol = 0.0, const char* method = nullptr) {
  arma_extra_debug_sigprint();

  uword method_id = 0;  // default setting

  if (method != nullptr) {
    const char sig = method[0];

    arma_debug_check(((sig != 's') && (sig != 'd')), "pinv(): unknown method specified");

    if (sig == 's') {
      method_id = 1;
    }
    if (sig == 'd') {
      method_id = 2;
    }
  }

  const bool status = op_pinv::apply_direct(out, X.get_ref(), tol, method_id);

  if (status == false) {
    out.soft_reset();
    arma_debug_warn_level(3, "pinv(): svd failed");
  }

  return status;
}

//! @}
