////////////////////////////////////////////////////////////////////////
//
// Copyright (C) 2008-2021 The Octave Project Developers
//
// See the file COPYRIGHT.md in the top-level directory of this
// distribution or <https://octave.org/copyright/>.
//
// This file is part of Octave.
//
// Octave is free software: you can redistribute it and/or modify it
// under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// Octave is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Octave; see the file COPYING.  If not, see
// <https://www.gnu.org/licenses/>.
//
////////////////////////////////////////////////////////////////////////

#if defined (HAVE_CONFIG_H)
#  include "config.h"
#endif

#include "byte-swap.h"

#include "ov-re-diag.h"
#include "ov-flt-re-diag.h"
#include "ov-base-diag.cc"
#include "ov-scalar.h"
#include "ov-re-mat.h"
#include "ls-utils.h"


template class octave_base_diag<DiagMatrix, Matrix>;

DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_diag_matrix, "diagonal matrix",
                                     "double");

static octave_base_value *
default_numeric_conversion_function (const octave_base_value& a)
{
  const octave_diag_matrix& v = dynamic_cast<const octave_diag_matrix&> (a);

  return new octave_matrix (v.matrix_value ());
}

octave_base_value::type_conv_info
octave_diag_matrix::numeric_conversion_function (void) const
{
  return octave_base_value::type_conv_info (default_numeric_conversion_function,
                                            octave_matrix::static_type_id ());
}

static octave_base_value *
default_numeric_demotion_function (const octave_base_value& a)
{
  const octave_diag_matrix& v = dynamic_cast<const octave_diag_matrix&> (a);

  return new octave_float_diag_matrix (v.float_diag_matrix_value ());
}

octave_base_value::type_conv_info
octave_diag_matrix::numeric_demotion_function (void) const
{
  return octave_base_value::type_conv_info
           (default_numeric_demotion_function,
            octave_float_diag_matrix::static_type_id ());
}

octave_base_value *
octave_diag_matrix::try_narrowing_conversion (void)
{
  octave_base_value *retval = nullptr;

  if (m_matrix.nelem () == 1)
    retval = new octave_scalar (m_matrix (0, 0));

  return retval;
}

octave_value
octave_diag_matrix::do_index_op (const octave_value_list& idx,
                                 bool resize_ok)
{
  octave_value retval;

  // This hack is to allow constructing permutation matrices using
  // eye(n)(p,:), eye(n)(:,q) && eye(n)(p,q) where p & q are permutation
  // vectors.
  if (! resize_ok && idx.length () == 2 && m_matrix.is_multiple_of_identity (1))
    {
      int k = 0;        // index we're accessing when index_vector throws
      try
        {
          octave::idx_vector idx0 = idx(0).index_vector ();
          k = 1;
          octave::idx_vector idx1 = idx(1).index_vector ();

          bool left = idx0.is_permutation (m_matrix.rows ());
          bool right = idx1.is_permutation (m_matrix.cols ());

          if (left && right)
            {
              if (idx0.is_colon ()) left = false;
              if (idx1.is_colon ()) right = false;
              if (left && right)
                retval = PermMatrix (idx0, false) * PermMatrix (idx1, true);
              else if (left)
                retval = PermMatrix (idx0, false);
              else if (right)
                retval = PermMatrix (idx1, true);
              else
                {
                  retval = this;
                  this->count++;
                }
            }
        }
      catch (octave::index_exception& ie)
        {
          // Rethrow to allow more info to be reported later.
          ie.set_pos_if_unset (2, k+1);
          throw;
        }
    }

  if (retval.is_undefined ())
    retval = octave_base_diag<DiagMatrix, Matrix>::do_index_op (idx, resize_ok);

  return retval;
}

DiagMatrix
octave_diag_matrix::diag_matrix_value (bool) const
{
  return m_matrix;
}

FloatDiagMatrix
octave_diag_matrix::float_diag_matrix_value (bool) const
{
  return FloatDiagMatrix (m_matrix);
}

ComplexDiagMatrix
octave_diag_matrix::complex_diag_matrix_value (bool) const
{
  return ComplexDiagMatrix (m_matrix);
}

FloatComplexDiagMatrix
octave_diag_matrix::float_complex_diag_matrix_value (bool) const
{
  return FloatComplexDiagMatrix (m_matrix);
}

octave_value
octave_diag_matrix::as_double (void) const
{
  return m_matrix;
}

octave_value
octave_diag_matrix::as_single (void) const
{
  return FloatDiagMatrix (m_matrix);
}

octave_value
octave_diag_matrix::as_int8 (void) const
{
  return int8_array_value ();
}

octave_value
octave_diag_matrix::as_int16 (void) const
{
  return int16_array_value ();
}

octave_value
octave_diag_matrix::as_int32 (void) const
{
  return int32_array_value ();
}

octave_value
octave_diag_matrix::as_int64 (void) const
{
  return int64_array_value ();
}

octave_value
octave_diag_matrix::as_uint8 (void) const
{
  return uint8_array_value ();
}

octave_value
octave_diag_matrix::as_uint16 (void) const
{
  return uint16_array_value ();
}

octave_value
octave_diag_matrix::as_uint32 (void) const
{
  return uint32_array_value ();
}

octave_value
octave_diag_matrix::as_uint64 (void) const
{
  return uint64_array_value ();
}

octave_value
octave_diag_matrix::map (unary_mapper_t umap) const
{
  switch (umap)
    {
    case umap_abs:
      return m_matrix.abs ();
    case umap_real:
    case umap_conj:
      return m_matrix;
    case umap_imag:
      return DiagMatrix (m_matrix.rows (), m_matrix.cols (), 0.0);
    case umap_sqrt:
      {
        ComplexColumnVector tmp;
        tmp = m_matrix.extract_diag ().map<Complex> (octave::math::rc_sqrt);
        ComplexDiagMatrix retval (tmp);
        retval.resize (m_matrix.rows (), m_matrix.columns ());
        return retval;
      }
    default:
      return to_dense ().map (umap);
    }
}

bool
octave_diag_matrix::save_binary (std::ostream& os, bool save_as_floats)
{

  int32_t r = m_matrix.rows ();
  int32_t c = m_matrix.cols ();
  os.write (reinterpret_cast<char *> (&r), 4);
  os.write (reinterpret_cast<char *> (&c), 4);

  Matrix m = Matrix (m_matrix.extract_diag ());
  save_type st = LS_DOUBLE;
  if (save_as_floats)
    {
      if (m.too_large_for_float ())
        {
          warning ("save: some values too large to save as floats --");
          warning ("save: saving as doubles instead");
        }
      else
        st = LS_FLOAT;
    }
  else if (m_matrix.length () > 8192) // FIXME: make this configurable.
    {
      double max_val, min_val;
      if (m.all_integers (max_val, min_val))
        st = octave::get_save_type (max_val, min_val);
    }

  const double *mtmp = m.data ();
  write_doubles (os, mtmp, st, m.numel ());

  return true;
}

bool
octave_diag_matrix::load_binary (std::istream& is, bool swap,
                                 octave::mach_info::float_format fmt)
{
  int32_t r, c;
  char tmp;
  if (! (is.read (reinterpret_cast<char *> (&r), 4)
         && is.read (reinterpret_cast<char *> (&c), 4)
         && is.read (reinterpret_cast<char *> (&tmp), 1)))
    return false;
  if (swap)
    {
      swap_bytes<4> (&r);
      swap_bytes<4> (&c);
    }

  DiagMatrix m (r, c);
  double *re = m.fortran_vec ();
  octave_idx_type len = m.length ();
  read_doubles (is, re, static_cast<save_type> (tmp), len, swap, fmt);

  if (! is)
    return false;

  m_matrix = m;

  return true;
}

bool
octave_diag_matrix::chk_valid_scalar (const octave_value& val,
                                      double& x) const
{
  bool retval = val.is_real_scalar ();
  if (retval)
    x = val.double_value ();
  return retval;
}