// 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 op_sum
//! @{

template <typename T1>
inline void op_sum::apply(Mat<typename T1::elem_type>& out, const Op<T1, op_sum>& in) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const uword dim = in.aux_uword_a;
  arma_conform_check((dim > 1), "sum(): parameter 'dim' must be 0 or 1");

  const Proxy<T1> P(in.m);

  if (P.is_alias(out) == false) {
    op_sum::apply_noalias(out, P, dim);
  } else {
    Mat<eT> tmp;

    op_sum::apply_noalias(tmp, P, dim);

    out.steal_mem(tmp);
  }
}

template <typename T1>
inline void op_sum::apply_noalias(Mat<typename T1::elem_type>& out, const Proxy<T1>& P,
                                  const uword dim) {
  arma_debug_sigprint();

  if (is_Mat<typename Proxy<T1>::stored_type>::value ||
      (arma_config::openmp && Proxy<T1>::use_mp)) {
    op_sum::apply_noalias_unwrap(out, P, dim);
  } else {
    op_sum::apply_noalias_proxy(out, P, dim);
  }
}

template <typename T1>
inline void op_sum::apply_noalias_unwrap(Mat<typename T1::elem_type>& out,
                                         const Proxy<T1>& P, const uword dim) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  typedef typename Proxy<T1>::stored_type P_stored_type;

  const unwrap<P_stored_type> tmp(P.Q);

  const typename unwrap<P_stored_type>::stored_type& X = tmp.M;

  const uword X_n_rows = X.n_rows;
  const uword X_n_cols = X.n_cols;

  const uword out_n_rows = (dim == 0) ? uword(1) : X_n_rows;
  const uword out_n_cols = (dim == 0) ? X_n_cols : uword(1);

  out.set_size(out_n_rows, out_n_cols);

  if (X.n_elem == 0) {
    out.zeros();
    return;
  }

  const eT* X_colptr = X.memptr();
  eT* out_mem = out.memptr();

  if (dim == 0) {
    for (uword col = 0; col < X_n_cols; ++col) {
      out_mem[col] = arrayops::accumulate(X_colptr, X_n_rows);

      X_colptr += X_n_rows;
    }
  } else {
    arrayops::copy(out_mem, X_colptr, X_n_rows);

    X_colptr += X_n_rows;

    for (uword col = 1; col < X_n_cols; ++col) {
      arrayops::inplace_plus(out_mem, X_colptr, X_n_rows);

      X_colptr += X_n_rows;
    }
  }
}

template <typename T1>
inline void op_sum::apply_noalias_proxy(Mat<typename T1::elem_type>& out,
                                        const Proxy<T1>& P, const uword dim) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const uword P_n_rows = P.get_n_rows();
  const uword P_n_cols = P.get_n_cols();

  const uword out_n_rows = (dim == 0) ? uword(1) : P_n_rows;
  const uword out_n_cols = (dim == 0) ? P_n_cols : uword(1);

  out.set_size(out_n_rows, out_n_cols);

  if (P.get_n_elem() == 0) {
    out.zeros();
    return;
  }

  eT* out_mem = out.memptr();

  if (Proxy<T1>::use_at == false) {
    if (dim == 0) {
      uword count = 0;

      for (uword col = 0; col < P_n_cols; ++col) {
        eT val1 = eT(0);
        eT val2 = eT(0);

        uword j;
        for (j = 1; j < P_n_rows; j += 2) {
          val1 += P[count];
          ++count;
          val2 += P[count];
          ++count;
        }

        if ((j - 1) < P_n_rows) {
          val1 += P[count];
          ++count;
        }

        out_mem[col] = (val1 + val2);
      }
    } else {
      uword count = 0;

      for (uword row = 0; row < P_n_rows; ++row) {
        out_mem[row] = P[count];
        ++count;
      }

      for (uword col = 1; col < P_n_cols; ++col)
        for (uword row = 0; row < P_n_rows; ++row) {
          out_mem[row] += P[count];
          ++count;
        }
    }
  } else {
    if (dim == 0) {
      for (uword col = 0; col < P_n_cols; ++col) {
        eT val1 = eT(0);
        eT val2 = eT(0);

        uword i, j;
        for (i = 0, j = 1; j < P_n_rows; i += 2, j += 2) {
          val1 += P.at(i, col);
          val2 += P.at(j, col);
        }

        if (i < P_n_rows) {
          val1 += P.at(i, col);
        }

        out_mem[col] = (val1 + val2);
      }
    } else {
      for (uword row = 0; row < P_n_rows; ++row) {
        out_mem[row] = P.at(row, 0);
      }

      for (uword col = 1; col < P_n_cols; ++col)
        for (uword row = 0; row < P_n_rows; ++row) {
          out_mem[row] += P.at(row, col);
        }
    }
  }
}

//
// cubes

template <typename T1>
inline void op_sum::apply(Cube<typename T1::elem_type>& out,
                          const OpCube<T1, op_sum>& in) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const uword dim = in.aux_uword_a;
  arma_conform_check((dim > 2), "sum(): parameter 'dim' must be 0 or 1 or 2");

  const ProxyCube<T1> P(in.m);

  if (P.is_alias(out) == false) {
    op_sum::apply_noalias(out, P, dim);
  } else {
    Cube<eT> tmp;

    op_sum::apply_noalias(tmp, P, dim);

    out.steal_mem(tmp);
  }
}

template <typename T1>
inline void op_sum::apply_noalias(Cube<typename T1::elem_type>& out,
                                  const ProxyCube<T1>& P, const uword dim) {
  arma_debug_sigprint();

  if (is_Cube<typename ProxyCube<T1>::stored_type>::value ||
      (arma_config::openmp && ProxyCube<T1>::use_mp)) {
    op_sum::apply_noalias_unwrap(out, P, dim);
  } else {
    op_sum::apply_noalias_proxy(out, P, dim);
  }
}

template <typename T1>
inline void op_sum::apply_noalias_unwrap(Cube<typename T1::elem_type>& out,
                                         const ProxyCube<T1>& P, const uword dim) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  typedef typename ProxyCube<T1>::stored_type P_stored_type;

  const unwrap_cube<P_stored_type> tmp(P.Q);

  const Cube<eT>& X = tmp.M;

  const uword X_n_rows = X.n_rows;
  const uword X_n_cols = X.n_cols;
  const uword X_n_slices = X.n_slices;

  if (dim == 0) {
    out.set_size(1, X_n_cols, X_n_slices);

    for (uword slice = 0; slice < X_n_slices; ++slice) {
      eT* out_mem = out.slice_memptr(slice);

      for (uword col = 0; col < X_n_cols; ++col) {
        out_mem[col] = arrayops::accumulate(X.slice_colptr(slice, col), X_n_rows);
      }
    }
  } else if (dim == 1) {
    out.zeros(X_n_rows, 1, X_n_slices);

    for (uword slice = 0; slice < X_n_slices; ++slice) {
      eT* out_mem = out.slice_memptr(slice);

      for (uword col = 0; col < X_n_cols; ++col) {
        arrayops::inplace_plus(out_mem, X.slice_colptr(slice, col), X_n_rows);
      }
    }
  } else if (dim == 2) {
    out.zeros(X_n_rows, X_n_cols, 1);

    eT* out_mem = out.memptr();

    for (uword slice = 0; slice < X_n_slices; ++slice) {
      arrayops::inplace_plus(out_mem, X.slice_memptr(slice), X.n_elem_slice);
    }
  }
}

template <typename T1>
inline void op_sum::apply_noalias_proxy(Cube<typename T1::elem_type>& out,
                                        const ProxyCube<T1>& P, const uword dim) {
  arma_debug_sigprint();

  typedef typename T1::elem_type eT;

  const uword P_n_rows = P.get_n_rows();
  const uword P_n_cols = P.get_n_cols();
  const uword P_n_slices = P.get_n_slices();

  if (dim == 0) {
    out.set_size(1, P_n_cols, P_n_slices);

    for (uword slice = 0; slice < P_n_slices; ++slice) {
      eT* out_mem = out.slice_memptr(slice);

      for (uword col = 0; col < P_n_cols; ++col) {
        eT val1 = eT(0);
        eT val2 = eT(0);

        uword i, j;
        for (i = 0, j = 1; j < P_n_rows; i += 2, j += 2) {
          val1 += P.at(i, col, slice);
          val2 += P.at(j, col, slice);
        }

        if (i < P_n_rows) {
          val1 += P.at(i, col, slice);
        }

        out_mem[col] = (val1 + val2);
      }
    }
  } else if (dim == 1) {
    out.zeros(P_n_rows, 1, P_n_slices);

    for (uword slice = 0; slice < P_n_slices; ++slice) {
      eT* out_mem = out.slice_memptr(slice);

      for (uword col = 0; col < P_n_cols; ++col)
        for (uword row = 0; row < P_n_rows; ++row) {
          out_mem[row] += P.at(row, col, slice);
        }
    }
  } else if (dim == 2) {
    out.zeros(P_n_rows, P_n_cols, 1);

    for (uword slice = 0; slice < P_n_slices; ++slice) {
      for (uword col = 0; col < P_n_cols; ++col) {
        eT* out_mem = out.slice_colptr(0, col);

        for (uword row = 0; row < P_n_rows; ++row) {
          out_mem[row] += P.at(row, col, slice);
        }
      }
    }
  }
}

//! @}
