// 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_inv
//! @{

template <typename T1>
arma_warn_unused arma_inline
    typename enable_if2<is_supported_blas_type<typename T1::elem_type>::value,
                        const Op<T1, op_inv_gen_default> >::result
    inv(const Base<typename T1::elem_type, T1>& X) {
  arma_debug_sigprint();

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

template <typename T1>
inline typename enable_if2<is_supported_blas_type<typename T1::elem_type>::value,
                           bool>::result
inv(Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type, T1>& X) {
  arma_debug_sigprint();

  const bool status = op_inv_gen_default::apply_direct(out, X.get_ref(), "inv()");

  if (status == false) {
    out.soft_reset();
    arma_warn(3, "inv(): matrix is singular");
  }

  return status;
}

template <typename T1>
arma_warn_unused arma_inline
    typename enable_if2<is_supported_blas_type<typename T1::elem_type>::value,
                        const Op<T1, op_inv_gen_full> >::result
    inv(const Base<typename T1::elem_type, T1>& X, const inv_opts::opts& opts) {
  arma_debug_sigprint();

  return Op<T1, op_inv_gen_full>(X.get_ref(), opts.flags, uword(0));
}

template <typename T1>
inline typename enable_if2<is_supported_blas_type<typename T1::elem_type>::value,
                           bool>::result
inv(Mat<typename T1::elem_type>& out, const Base<typename T1::elem_type, T1>& X,
    const inv_opts::opts& opts) {
  arma_debug_sigprint();

  const bool status =
      op_inv_gen_full::apply_direct(out, X.get_ref(), "inv()", opts.flags);

  if (status == false) {
    out.soft_reset();
    arma_warn(3, "inv(): matrix is singular");
  }

  return status;
}

template <typename T1>
inline typename enable_if2<is_supported_blas_type<typename T1::elem_type>::value,
                           bool>::result
inv(Mat<typename T1::elem_type>& out_inv, typename T1::pod_type& out_rcond,
    const Base<typename T1::elem_type, T1>& X) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  op_inv_gen_state<T> inv_state;

  const bool status = op_inv_gen_rcond::apply_direct(out_inv, inv_state, X.get_ref());

  out_rcond = inv_state.rcond;

  if (status == false) {
    out_rcond = T(0);
    out_inv.soft_reset();
    arma_warn(3, "inv(): matrix is singular");
  }

  return status;
}

//! @}
