// 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_eigs_gen
//! @{

//! eigenvalues of general sparse matrix X
template <typename T1>
arma_warn_unused inline
    typename enable_if2<is_real<typename T1::pod_type>::value,
                        Col<std::complex<typename T1::pod_type> > >::result
    eigs_gen(const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
             const char* form = "lm", const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  Mat<std::complex<T> > eigvec;
  Col<std::complex<T> > eigval;

  sp_auxlib::form_type form_val = sp_auxlib::interpret_form_str(form);

  const bool status = sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, form_val, opts);

  if (status == false) {
    eigval.soft_reset();
    arma_stop_runtime_error("eigs_gen(): decomposition failed");
  }

  return eigval;
}

//! this form is deprecated; use eigs_gen(X, n_eigvals, form, opts) instead
template <typename T1>
arma_deprecated inline
    typename enable_if2<is_real<typename T1::pod_type>::value,
                        Col<std::complex<typename T1::pod_type> > >::result
    eigs_gen(const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
             const char* form, const typename T1::pod_type tol) {
  arma_debug_sigprint();

  eigs_opts opts;
  opts.tol = tol;

  return eigs_gen(X, n_eigvals, form, opts);
}

template <typename T1>
arma_warn_unused inline
    typename enable_if2<is_real<typename T1::pod_type>::value,
                        Col<std::complex<typename T1::pod_type> > >::result
    eigs_gen(const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
             const std::complex<typename T1::pod_type> sigma,
             const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  Mat<std::complex<T> > eigvec;
  Col<std::complex<T> > eigval;

  bool status = false;

  // If X is real and sigma is truly complex, treat X as complex.
  // The reason is that we are still not able to apply truly complex shifts to real
  // matrices
  if ((is_real<typename T1::elem_type>::yes) && (std::imag(sigma) != T(0))) {
    status =
        sp_auxlib::eigs_gen(eigval, eigvec, conv_to<SpMat<std::complex<T> > >::from(X),
                            n_eigvals, sigma, opts);
  } else {
    status = sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, sigma, opts);
  }

  if (status == false) {
    eigval.soft_reset();
    arma_stop_runtime_error("eigs_gen(): decomposition failed");
  }

  return eigval;
}

template <typename T1>
arma_warn_unused inline
    typename enable_if2<is_real<typename T1::pod_type>::value,
                        Col<std::complex<typename T1::pod_type> > >::result
    eigs_gen(const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
             const double sigma, const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  Mat<std::complex<T> > eigvec;
  Col<std::complex<T> > eigval;

  const bool status =
      sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, std::complex<T>(T(sigma)), opts);

  if (status == false) {
    eigval.soft_reset();
    arma_stop_runtime_error("eigs_gen(): decomposition failed");
  }

  return eigval;
}

//! eigenvalues of general sparse matrix X
template <typename T1>
inline typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result eigs_gen(
    Col<std::complex<typename T1::pod_type> >& eigval,
    const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
    const char* form = "lm", const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  Mat<std::complex<T> > eigvec;

  sp_auxlib::form_type form_val = sp_auxlib::interpret_form_str(form);

  const bool status = sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, form_val, opts);

  if (status == false) {
    eigval.soft_reset();
    arma_warn(3, "eigs_gen(): decomposition failed");
  }

  return status;
}

//! this form is deprecated; use eigs_gen(eigval, X, n_eigvals, form, opts) instead
template <typename T1>
arma_deprecated inline
    typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result
    eigs_gen(Col<std::complex<typename T1::pod_type> >& eigval,
             const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
             const char* form, const typename T1::pod_type tol) {
  arma_debug_sigprint();

  eigs_opts opts;
  opts.tol = tol;

  return eigs_gen(eigval, X, n_eigvals, form, opts);
}

template <typename T1>
inline typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result eigs_gen(
    Col<std::complex<typename T1::pod_type> >& eigval,
    const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
    const std::complex<typename T1::pod_type> sigma, const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  Mat<std::complex<T> > eigvec;

  bool status = false;

  // If X is real and sigma is truly complex, treat X as complex.
  // The reason is that we are still not able to apply truly complex shifts to real
  // matrices
  if ((is_real<typename T1::elem_type>::yes) && (std::imag(sigma) != T(0))) {
    status =
        sp_auxlib::eigs_gen(eigval, eigvec, conv_to<SpMat<std::complex<T> > >::from(X),
                            n_eigvals, sigma, opts);
  } else {
    status = sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, sigma, opts);
  }

  if (status == false) {
    eigval.soft_reset();
    arma_warn(3, "eigs_gen(): decomposition failed");
  }

  return status;
}

template <typename T1>
inline typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result eigs_gen(
    Col<std::complex<typename T1::pod_type> >& eigval,
    const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
    const double sigma, const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  Mat<std::complex<T> > eigvec;

  const bool status =
      sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, std::complex<T>(T(sigma)), opts);

  if (status == false) {
    eigval.soft_reset();
    arma_warn(3, "eigs_gen(): decomposition failed");
  }

  return status;
}

//! eigenvalues and eigenvectors of general sparse matrix X
template <typename T1>
inline typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result eigs_gen(
    Col<std::complex<typename T1::pod_type> >& eigval,
    Mat<std::complex<typename T1::pod_type> >& eigvec,
    const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
    const char* form = "lm", const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  // typedef typename T1::pod_type T;

  arma_conform_check(void_ptr(&eigval) == void_ptr(&eigvec),
                     "eigs_gen(): parameter 'eigval' is an alias of parameter 'eigvec'");

  sp_auxlib::form_type form_val = sp_auxlib::interpret_form_str(form);

  const bool status = sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, form_val, opts);

  if (status == false) {
    eigval.soft_reset();
    eigvec.soft_reset();
    arma_warn(3, "eigs_gen(): decomposition failed");
  }

  return status;
}

//! this form is deprecated; use eigs_gen(eigval, eigvec, X, n_eigvals, form, opts)
//! instead
template <typename T1>
arma_deprecated inline
    typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result
    eigs_gen(Col<std::complex<typename T1::pod_type> >& eigval,
             Mat<std::complex<typename T1::pod_type> >& eigvec,
             const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
             const char* form, const typename T1::pod_type tol) {
  arma_debug_sigprint();

  eigs_opts opts;
  opts.tol = tol;

  return eigs_gen(eigval, eigvec, X, n_eigvals, form, opts);
}

template <typename T1>
inline typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result eigs_gen(
    Col<std::complex<typename T1::pod_type> >& eigval,
    Mat<std::complex<typename T1::pod_type> >& eigvec,
    const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
    const std::complex<typename T1::pod_type> sigma, const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  arma_conform_check(void_ptr(&eigval) == void_ptr(&eigvec),
                     "eigs_gen(): parameter 'eigval' is an alias of parameter 'eigvec'");

  bool status = false;

  // If X is real and sigma is truly complex, treat X as complex.
  // The reason is that we are still not able to apply truly complex shifts to real
  // matrices
  if ((is_real<typename T1::elem_type>::yes) && (std::imag(sigma) != T(0))) {
    status =
        sp_auxlib::eigs_gen(eigval, eigvec, conv_to<SpMat<std::complex<T> > >::from(X),
                            n_eigvals, sigma, opts);
  } else {
    status = sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, sigma, opts);
  }

  if (status == false) {
    eigval.soft_reset();
    eigvec.soft_reset();
    arma_warn(3, "eigs_gen(): decomposition failed");
  }

  return status;
}

template <typename T1>
inline typename enable_if2<is_real<typename T1::pod_type>::value, bool>::result eigs_gen(
    Col<std::complex<typename T1::pod_type> >& eigval,
    Mat<std::complex<typename T1::pod_type> >& eigvec,
    const SpBase<typename T1::elem_type, T1>& X, const uword n_eigvals,
    const double sigma, const eigs_opts opts = eigs_opts()) {
  arma_debug_sigprint();

  typedef typename T1::pod_type T;

  arma_conform_check(void_ptr(&eigval) == void_ptr(&eigvec),
                     "eigs_gen(): parameter 'eigval' is an alias of parameter 'eigvec'");

  const bool status =
      sp_auxlib::eigs_gen(eigval, eigvec, X, n_eigvals, std::complex<T>(T(sigma)), opts);

  if (status == false) {
    eigval.soft_reset();
    eigvec.soft_reset();
    arma_warn(3, "eigs_gen(): decomposition failed");
  }

  return status;
}

//! @}
