// 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 operator_times
//! @{

//! Base * scalar
template <typename T1>
arma_inline
    typename enable_if2<is_arma_type<T1>::value, const eOp<T1, eop_scalar_times> >::result
    operator*(const T1& X, const typename T1::elem_type k) {
  arma_debug_sigprint();

  return eOp<T1, eop_scalar_times>(X, k);
}

//! scalar * Base
template <typename T1>
arma_inline
    typename enable_if2<is_arma_type<T1>::value, const eOp<T1, eop_scalar_times> >::result
    operator*(const typename T1::elem_type k, const T1& X) {
  arma_debug_sigprint();

  return eOp<T1, eop_scalar_times>(X, k);  // NOTE: order is swapped
}

//! non-complex Base * complex scalar
template <typename T1>
arma_inline
    typename enable_if2<(is_arma_type<T1>::value && is_cx<typename T1::elem_type>::no),
                        const mtOp<typename std::complex<typename T1::pod_type>, T1,
                                   op_cx_scalar_times> >::result
    operator*(const T1& X, const std::complex<typename T1::pod_type>& k) {
  arma_debug_sigprint();

  return mtOp<typename std::complex<typename T1::pod_type>, T1, op_cx_scalar_times>('j',
                                                                                    X, k);
}

//! complex scalar * non-complex Base
template <typename T1>
arma_inline
    typename enable_if2<(is_arma_type<T1>::value && is_cx<typename T1::elem_type>::no),
                        const mtOp<typename std::complex<typename T1::pod_type>, T1,
                                   op_cx_scalar_times> >::result
    operator*(const std::complex<typename T1::pod_type>& k, const T1& X) {
  arma_debug_sigprint();

  return mtOp<typename std::complex<typename T1::pod_type>, T1, op_cx_scalar_times>('j',
                                                                                    X, k);
}

//! scalar * trans(T1)
template <typename T1>
arma_inline const Op<T1, op_htrans2> operator*(const typename T1::elem_type k,
                                               const Op<T1, op_htrans>& X) {
  arma_debug_sigprint();

  return Op<T1, op_htrans2>(X.m, k);
}

//! trans(T1) * scalar
template <typename T1>
arma_inline const Op<T1, op_htrans2> operator*(const Op<T1, op_htrans>& X,
                                               const typename T1::elem_type k) {
  arma_debug_sigprint();

  return Op<T1, op_htrans2>(X.m, k);
}

//! Base * diagmat
template <typename T1, typename T2>
arma_inline typename enable_if2<
    (is_arma_type<T1>::value &&
     is_same_type<typename T1::elem_type, typename T2::elem_type>::value),
    const Glue<T1, Op<T2, op_diagmat>, glue_times_diag> >::result
operator*(const T1& X, const Op<T2, op_diagmat>& Y) {
  arma_debug_sigprint();

  return Glue<T1, Op<T2, op_diagmat>, glue_times_diag>(X, Y);
}

//! diagmat * Base
template <typename T1, typename T2>
arma_inline typename enable_if2<
    (is_arma_type<T2>::value &&
     is_same_type<typename T1::elem_type, typename T2::elem_type>::value),
    const Glue<Op<T1, op_diagmat>, T2, glue_times_diag> >::result
operator*(const Op<T1, op_diagmat>& X, const T2& Y) {
  arma_debug_sigprint();

  return Glue<Op<T1, op_diagmat>, T2, glue_times_diag>(X, Y);
}

//! diagmat * diagmat
template <typename T1, typename T2>
inline Mat<typename promote_type<typename T1::elem_type, typename T2::elem_type>::result>
operator*(const Op<T1, op_diagmat>& X, const Op<T2, op_diagmat>& Y) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT1;
  typedef typename T2::elem_type eT2;

  typedef typename promote_type<eT1, eT2>::result out_eT;

  promote_type<eT1, eT2>::check();

  const diagmat_proxy<T1> A(X.m);
  const diagmat_proxy<T2> B(Y.m);

  arma_conform_assert_mul_size(A.n_rows, A.n_cols, B.n_rows, B.n_cols,
                               "matrix multiplication");

  Mat<out_eT> out(A.n_rows, B.n_cols, arma_zeros_indicator());

  const uword A_length = (std::min)(A.n_rows, A.n_cols);
  const uword B_length = (std::min)(B.n_rows, B.n_cols);

  const uword N = (std::min)(A_length, B_length);

  for (uword i = 0; i < N; ++i) {
    out.at(i, i) =
        upgrade_val<eT1, eT2>::apply(A[i]) * upgrade_val<eT1, eT2>::apply(B[i]);
  }

  return out;
}

//! multiplication of Base objects with same element type
template <typename T1, typename T2>
arma_inline typename enable_if2<
    is_arma_type<T1>::value && is_arma_type<T2>::value &&
        is_same_type<typename T1::elem_type, typename T2::elem_type>::value,
    const Glue<T1, T2, glue_times> >::result
operator*(const T1& X, const T2& Y) {
  arma_debug_sigprint();

  return Glue<T1, T2, glue_times>(X, Y);
}

//! multiplication of Base objects with different element types
template <typename T1, typename T2>
inline typename enable_if2<
    (is_arma_type<T1>::value && is_arma_type<T2>::value &&
     (is_same_type<typename T1::elem_type, typename T2::elem_type>::no)),
    const mtGlue<
        typename promote_type<typename T1::elem_type, typename T2::elem_type>::result, T1,
        T2, glue_mixed_times> >::result
operator*(const T1& X, const T2& Y) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT1;
  typedef typename T2::elem_type eT2;

  typedef typename promote_type<eT1, eT2>::result out_eT;

  promote_type<eT1, eT2>::check();

  return mtGlue<out_eT, T1, T2, glue_mixed_times>(X, Y);
}

//! sparse multiplied by scalar
template <typename T1>
inline typename enable_if2<is_arma_sparse_type<T1>::value,
                           SpOp<T1, spop_scalar_times> >::result
operator*(const T1& X, const typename T1::elem_type k) {
  arma_debug_sigprint();

  return SpOp<T1, spop_scalar_times>(X, k);
}

template <typename T1>
inline typename enable_if2<is_arma_sparse_type<T1>::value,
                           SpOp<T1, spop_scalar_times> >::result
operator*(const typename T1::elem_type k, const T1& X) {
  arma_debug_sigprint();

  return SpOp<T1, spop_scalar_times>(X, k);
}

//! non-complex sparse * complex scalar
template <typename T1>
arma_inline typename enable_if2<(is_arma_sparse_type<T1>::value &&
                                 is_cx<typename T1::elem_type>::no),
                                const mtSpOp<typename std::complex<typename T1::pod_type>,
                                             T1, spop_cx_scalar_times> >::result
operator*(const T1& X, const std::complex<typename T1::pod_type>& k) {
  arma_debug_sigprint();

  return mtSpOp<typename std::complex<typename T1::pod_type>, T1, spop_cx_scalar_times>(
      'j', X, k);
}

//! complex scalar * non-complex sparse
template <typename T1>
arma_inline typename enable_if2<(is_arma_sparse_type<T1>::value &&
                                 is_cx<typename T1::elem_type>::no),
                                const mtSpOp<typename std::complex<typename T1::pod_type>,
                                             T1, spop_cx_scalar_times> >::result
operator*(const std::complex<typename T1::pod_type>& k, const T1& X) {
  arma_debug_sigprint();

  return mtSpOp<typename std::complex<typename T1::pod_type>, T1, spop_cx_scalar_times>(
      'j', X, k);
}

//! multiplication of two sparse objects
template <typename T1, typename T2>
inline typename enable_if2<
    (is_arma_sparse_type<T1>::value && is_arma_sparse_type<T2>::value &&
     is_same_type<typename T1::elem_type, typename T2::elem_type>::value),
    const SpGlue<T1, T2, spglue_times> >::result
operator*(const T1& x, const T2& y) {
  arma_debug_sigprint();

  return SpGlue<T1, T2, spglue_times>(x, y);
}

//! multiplication of one sparse and one dense object
template <typename T1, typename T2>
inline typename enable_if2<
    (is_arma_sparse_type<T1>::value && is_arma_type<T2>::value &&
     is_same_type<typename T1::elem_type, typename T2::elem_type>::value),
    const SpToDGlue<T1, T2, glue_times_sparse_dense> >::result
operator*(const T1& x, const T2& y) {
  arma_debug_sigprint();

  return SpToDGlue<T1, T2, glue_times_sparse_dense>(x, y);
}

//! multiplication of one dense and one sparse object
template <typename T1, typename T2>
inline typename enable_if2<
    (is_arma_type<T1>::value && is_arma_sparse_type<T2>::value &&
     is_same_type<typename T1::elem_type, typename T2::elem_type>::value),
    const SpToDGlue<T1, T2, glue_times_dense_sparse> >::result
operator*(const T1& x, const T2& y) {
  arma_debug_sigprint();

  return SpToDGlue<T1, T2, glue_times_dense_sparse>(x, y);
}

//! multiplication of two sparse objects with different element types
template <typename T1, typename T2>
inline typename enable_if2<
    (is_arma_sparse_type<T1>::value && is_arma_sparse_type<T2>::value &&
     (is_same_type<typename T1::elem_type, typename T2::elem_type>::no)),
    const mtSpGlue<
        typename promote_type<typename T1::elem_type, typename T2::elem_type>::result, T1,
        T2, spglue_times_mixed> >::result
operator*(const T1& X, const T2& Y) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT1;
  typedef typename T2::elem_type eT2;

  typedef typename promote_type<eT1, eT2>::result out_eT;

  promote_type<eT1, eT2>::check();

  return mtSpGlue<out_eT, T1, T2, spglue_times_mixed>(X, Y);
}

//! multiplication of one sparse and one dense object with different element types
template <typename T1, typename T2>
inline typename enable_if2<
    (is_arma_sparse_type<T1>::value && is_arma_type<T2>::value &&
     is_same_type<typename T1::elem_type, typename T2::elem_type>::no),
    Mat<typename promote_type<typename T1::elem_type, typename T2::elem_type>::result> >::
    result
    operator*(const T1& X, const T2& Y) {
  arma_debug_sigprint();

  Mat<typename promote_type<typename T1::elem_type, typename T2::elem_type>::result> out;

  glue_times_sparse_dense::apply_mixed(out, X, Y);

  return out;
}

//! multiplication of one dense and one sparse object with different element types
template <typename T1, typename T2>
inline typename enable_if2<
    (is_arma_type<T1>::value && is_arma_sparse_type<T2>::value &&
     is_same_type<typename T1::elem_type, typename T2::elem_type>::no),
    Mat<typename promote_type<typename T1::elem_type, typename T2::elem_type>::result> >::
    result
    operator*(const T1& X, const T2& Y) {
  arma_debug_sigprint();

  Mat<typename promote_type<typename T1::elem_type, typename T2::elem_type>::result> out;

  glue_times_dense_sparse::apply_mixed(out, X, Y);

  return out;
}

//! @}
