/*

Copyright (C) 1996-2015 John W. Eaton

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
<http://www.gnu.org/licenses/>.

*/

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <iostream>

#include "lo-ieee.h"
#include "lo-utils.h"

#include "defun.h"
#include "variables.h"
#include "gripes.h"
#include "mxarray.h"
#include "ops.h"
#include "oct-obj.h"
#include "ov-range.h"
#include "ov-re-mat.h"
#include "ov-scalar.h"
#include "pr-output.h"

#include "byte-swap.h"
#include "ls-ascii-helper.h"
#include "ls-hdf5.h"
#include "ls-utils.h"

// If TRUE, allow ranges with non-integer elements as array indices.
static bool Vallow_noninteger_range_as_index = true;


DEFINE_OV_TYPEID_FUNCTIONS_AND_DATA (octave_range, "range", "double");

static octave_base_value *
default_numeric_conversion_function (const octave_base_value& a)
{
  CAST_CONV_ARG (const octave_range&);

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

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

octave_base_value *
octave_range::try_narrowing_conversion (void)
{
  octave_base_value *retval = 0;

  switch (range.nelem ())
    {
    case 1:
      retval = new octave_scalar (range.base ());
      break;

    case 0:
      retval = new octave_matrix (Matrix (1, 0));
      break;

    case -2:
      retval = new octave_matrix (range.matrix_value ());
      break;

    default:
      break;
    }

  return retval;
}

octave_value
octave_range::subsref (const std::string& type,
                       const std::list<octave_value_list>& idx)
{
  octave_value retval;

  switch (type[0])
    {
    case '(':
      retval = do_index_op (idx.front ());
      break;

    case '{':
    case '.':
      {
        std::string nm = type_name ();
        error ("%s cannot be indexed with %c", nm.c_str (), type[0]);
      }
      break;

    default:
      panic_impossible ();
    }

  return retval.next_subsref (type, idx);
}

octave_value
octave_range::do_index_op (const octave_value_list& idx, bool resize_ok)
{
  if (idx.length () == 1 && ! resize_ok)
    {
      octave_value retval;

      // The range can handle a single subscript.
      idx_vector i = idx(0).index_vector ();
      if (! error_state)
        {
          if (i.is_scalar () && i(0) < range.nelem ())
            retval = range.elem (i(0));
          else
            retval = range.index (i);
        }

      return retval;
    }
  else
    {
      octave_value tmp (new octave_matrix (range.matrix_value ()));

      return tmp.do_index_op (idx, resize_ok);
    }
}

idx_vector
octave_range::index_vector (bool require_integers) const
{
  if (idx_cache)
    return *idx_cache;
  else
    {
      if (require_integers
          || ! Vallow_noninteger_range_as_index
          || range.all_elements_are_ints ())
        return set_idx_cache (idx_vector (range));
      else
        {
          warning_with_id ("Octave:noninteger-range-as-index",
                           "non-integer range used as index");

          return octave_value (matrix_value ()).round ().index_vector ();
        }
    }
}

double
octave_range::double_value (bool) const
{
  double retval = lo_ieee_nan_value ();

  octave_idx_type nel = range.nelem ();

  if (nel > 0)
    {
      gripe_implicit_conversion ("Octave:array-to-scalar",
                                 "range", "real scalar");

      retval = range.base ();
    }
  else
    gripe_invalid_conversion ("range", "real scalar");

  return retval;
}

float
octave_range::float_value (bool) const
{
  float retval = lo_ieee_float_nan_value ();

  octave_idx_type nel = range.nelem ();

  if (nel > 0)
    {
      gripe_implicit_conversion ("Octave:array-to-scalar",
                                 "range", "real scalar");

      retval = range.base ();
    }
  else
    gripe_invalid_conversion ("range", "real scalar");

  return retval;
}

charNDArray
octave_range::char_array_value (bool) const
{
  const Matrix matrix = range.matrix_value ();
  charNDArray retval (dims ());

  octave_idx_type nel = numel ();

  for (octave_idx_type i = 0; i < nel; i++)
    retval.elem (i) = static_cast<char>(matrix.elem (i));

  return retval;
}

octave_value
octave_range::all (int dim) const
{
  // FIXME: this is a potential waste of memory.

  Matrix m = range.matrix_value ();

  return m.all (dim);
}

octave_value
octave_range::any (int dim) const
{
  // FIXME: this is a potential waste of memory.

  Matrix m = range.matrix_value ();

  return m.any (dim);
}

octave_value
octave_range::diag (octave_idx_type k) const
{
  return
    (k == 0
       ? octave_value (DiagMatrix (DiagArray2<double> (range.matrix_value ())))
       : octave_value (range.diag (k)));
}

octave_value
octave_range::diag (octave_idx_type m, octave_idx_type n) const
{
  Matrix mat = range.matrix_value ();

  return mat.diag (m, n);
}

bool
octave_range::is_true (void) const
{
  bool retval = false;

  if (range.nelem () != 0)
    {
      // FIXME: this is a potential waste of memory.

      Matrix m ((range.matrix_value () . all ()) . all ());

      retval = (m.rows () == 1 && m.columns () == 1 && m (0, 0) != 0.0);
    }

  return retval;
}

Complex
octave_range::complex_value (bool) const
{
  double tmp = lo_ieee_nan_value ();

  Complex retval (tmp, tmp);

  octave_idx_type nel = range.nelem ();

  if (nel > 0)
    {
      gripe_implicit_conversion ("Octave:array-to-scalar",
                                 "range", "complex scalar");

      retval = range.base ();
    }
  else
    gripe_invalid_conversion ("range", "complex scalar");

  return retval;
}

FloatComplex
octave_range::float_complex_value (bool) const
{
  float tmp = lo_ieee_float_nan_value ();

  FloatComplex retval (tmp, tmp);

  octave_idx_type nel = range.nelem ();

  if (nel > 0)
    {
      gripe_implicit_conversion ("Octave:array-to-scalar",
                                 "range", "complex scalar");

      retval = range.base ();
    }
  else
    gripe_invalid_conversion ("range", "complex scalar");

  return retval;
}

boolNDArray
octave_range::bool_array_value (bool warn) const
{
  Matrix m = range.matrix_value ();

  if (m.any_element_is_nan ())
    gripe_nan_to_logical_conversion ();
  else if (warn && m.any_element_not_one_or_zero ())
    gripe_logical_conversion ();

  return boolNDArray (m);
}

octave_value
octave_range::resize (const dim_vector& dv, bool fill) const
{
  NDArray retval = array_value ();
  if (fill)
    retval.resize (dv, 0);
  else
    retval.resize (dv);
  return retval;
}

octave_value
octave_range::convert_to_str_internal (bool pad, bool force, char type) const
{
  octave_value tmp (range.matrix_value ());
  return tmp.convert_to_str (pad, force, type);
}

void
octave_range::print (std::ostream& os, bool pr_as_read_syntax)
{
  print_raw (os, pr_as_read_syntax);
  newline (os);
}

void
octave_range::print_raw (std::ostream& os, bool pr_as_read_syntax) const
{
  octave_print_internal (os, range, pr_as_read_syntax,
                         current_print_indent_level ());
}

bool
octave_range::print_name_tag (std::ostream& os, const std::string& name) const
{
  bool retval = false;

  octave_idx_type n = range.nelem ();

  indent (os);

  if (n == 0 || n == 1)
    os << name << " = ";
  else
    {
      os << name << " =";
      newline (os);
      if (! Vcompact_format)
        newline (os);

      retval = true;
    }

  return retval;
}

void
octave_range::short_disp (std::ostream& os) const
{
  octave_idx_type len = range.nelem ();

  if (len == 0)
    os << "[]";
  else
    {
      os << range.base () << ":";

      if (len > 1)
        {
          if (range.inc () != 1)
            os << range.inc () << ":";

          os << range.limit ();
        }
    }
}

// Skip white space and comments on stream IS.

static void
skip_comments (std::istream& is)
{
  char c = '\0';
  while (is.get (c))
    {
      if (c == ' ' || c == '\t' || c == '\n')
        ; // Skip whitespace on way to beginning of next line.
      else
        break;
    }

  skip_until_newline (is, false);
}

bool
octave_range::save_ascii (std::ostream& os)
{
  Range r = range_value ();
  double base = r.base ();
  double limit = r.limit ();
  double inc = r.inc ();
  octave_idx_type len = r.nelem ();

  if (inc != 0)
    os << "# base, limit, increment\n";
  else
    os << "# base, length, increment\n";

  octave_write_double (os, base);
  os << " ";
  if (inc != 0)
    octave_write_double (os, limit);
  else
    os << len;
  os << " ";
  octave_write_double (os, inc);
  os << "\n";

  return true;
}

bool
octave_range::load_ascii (std::istream& is)
{
  // # base, limit, range comment added by save ().
  skip_comments (is);

  double base, limit, inc;
  is >> base >> limit >> inc;

  if (!is)
    {
      error ("load: failed to load range constant");
      return false;
    }

  if (inc != 0)
    range = Range (base, limit, inc);
  else
    range = Range (base, inc, static_cast<octave_idx_type> (limit));

  return true;
}

bool
octave_range::save_binary (std::ostream& os, bool& /* save_as_floats */)
{
  char tmp = LS_DOUBLE;
  os.write (reinterpret_cast<char *> (&tmp), 1);
  Range r = range_value ();
  double bas = r.base ();
  double lim = r.limit ();
  double inc = r.inc ();
  if (inc == 0)
    lim = r.nelem ();

  os.write (reinterpret_cast<char *> (&bas), 8);
  os.write (reinterpret_cast<char *> (&lim), 8);
  os.write (reinterpret_cast<char *> (&inc), 8);

  return true;
}

bool
octave_range::load_binary (std::istream& is, bool swap,
                           oct_mach_info::float_format /* fmt */)
{
  char tmp;
  if (! is.read (reinterpret_cast<char *> (&tmp), 1))
    return false;
  double bas, lim, inc;
  if (! is.read (reinterpret_cast<char *> (&bas), 8))
    return false;
  if (swap)
    swap_bytes<8> (&bas);
  if (! is.read (reinterpret_cast<char *> (&lim), 8))
    return false;
  if (swap)
    swap_bytes<8> (&lim);
  if (! is.read (reinterpret_cast<char *> (&inc), 8))
    return false;
  if (swap)
    swap_bytes<8> (&inc);
  if (inc != 0)
    range = Range (bas, lim, inc);
  else
    range = Range (bas, inc, static_cast<octave_idx_type> (lim));

  return true;
}

#if defined (HAVE_HDF5)

// The following subroutines creates an HDF5 representation of the way
// we will store Octave range types (triplets of floating-point numbers).
// NUM_TYPE is the HDF5 numeric type to use for storage (e.g.
// H5T_NATIVE_DOUBLE to save as 'double'). Note that any necessary
// conversions are handled automatically by HDF5.

static hid_t
hdf5_make_range_type (hid_t num_type)
{
  hid_t type_id = H5Tcreate (H5T_COMPOUND, sizeof (double) * 3);

  H5Tinsert (type_id, "base", 0 * sizeof (double), num_type);
  H5Tinsert (type_id, "limit", 1 * sizeof (double), num_type);
  H5Tinsert (type_id, "increment", 2 * sizeof (double), num_type);

  return type_id;
}

bool
octave_range::save_hdf5 (hid_t loc_id, const char *name,
                         bool /* save_as_floats */)
{
  hsize_t dimens[3];
  hid_t space_hid, type_hid, data_hid;
  space_hid = type_hid = data_hid = -1;
  bool retval = true;

  space_hid = H5Screate_simple (0, dimens, 0);
  if (space_hid < 0) return false;

  type_hid = hdf5_make_range_type (H5T_NATIVE_DOUBLE);
  if (type_hid < 0)
    {
      H5Sclose (space_hid);
      return false;
    }
#if HAVE_HDF5_18
  data_hid = H5Dcreate (loc_id, name, type_hid, space_hid,
                        H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT);
#else
  data_hid = H5Dcreate (loc_id, name, type_hid, space_hid, H5P_DEFAULT);
#endif
  if (data_hid < 0)
    {
      H5Sclose (space_hid);
      H5Tclose (type_hid);
      return false;
    }

  Range r = range_value ();
  double range_vals[3];
  range_vals[0] = r.base ();
  range_vals[1] = r.inc () != 0 ? r.limit () : r.nelem ();
  range_vals[2] = r.inc ();

  if (H5Dwrite (data_hid, type_hid, H5S_ALL, H5S_ALL, H5P_DEFAULT,
                range_vals) >= 0)
    {
      octave_idx_type nel = r.nelem ();
      retval = hdf5_add_scalar_attr (data_hid, H5T_NATIVE_IDX,
                                     "OCTAVE_RANGE_NELEM", &nel) >= 0;
    }
  else
    retval = false;

  H5Dclose (data_hid);
  H5Tclose (type_hid);
  H5Sclose (space_hid);

  return retval;
}

bool
octave_range::load_hdf5 (hid_t loc_id, const char *name)
{
  bool retval = false;

#if HAVE_HDF5_18
  hid_t data_hid = H5Dopen (loc_id, name, H5P_DEFAULT);
#else
  hid_t data_hid = H5Dopen (loc_id, name);
#endif
  hid_t type_hid = H5Dget_type (data_hid);

  hid_t range_type = hdf5_make_range_type (H5T_NATIVE_DOUBLE);

  if (! hdf5_types_compatible (type_hid, range_type))
    {
      H5Tclose (range_type);
      H5Dclose (data_hid);
      return false;
    }

  hid_t space_hid = H5Dget_space (data_hid);
  hsize_t rank = H5Sget_simple_extent_ndims (space_hid);

  if (rank != 0)
    {
      H5Tclose (range_type);
      H5Sclose (space_hid);
      H5Dclose (data_hid);
      return false;
    }

  double rangevals[3];
  if (H5Dread (data_hid, range_type, H5S_ALL, H5S_ALL, H5P_DEFAULT,
               rangevals) >= 0)
    {
      retval = true;
      octave_idx_type nel;
      if (hdf5_get_scalar_attr (data_hid, H5T_NATIVE_IDX,
                                "OCTAVE_RANGE_NELEM", &nel))
        range = Range (rangevals[0], rangevals[2], nel);
      else
        {
          if (rangevals[2] != 0)
            range = Range (rangevals[0], rangevals[1], rangevals[2]);
          else
            range = Range (rangevals[0], rangevals[2],
                           static_cast<octave_idx_type> (rangevals[1]));
        }
    }

  H5Tclose (range_type);
  H5Sclose (space_hid);
  H5Dclose (data_hid);

  return retval;
}

#endif

mxArray *
octave_range::as_mxArray (void) const
{
  mxArray *retval = new mxArray (mxDOUBLE_CLASS, dims (), mxREAL);

  double *pr = static_cast<double *> (retval->get_data ());

  mwSize nel = numel ();

  Matrix m = matrix_value ();

  const double *p = m.data ();

  for (mwSize i = 0; i < nel; i++)
    pr[i] = p[i];

  return retval;
}

octave_value
octave_range::fast_elem_extract (octave_idx_type n) const
{
  return (n < range.nelem ()) ? octave_value (range.elem (n))
                              : octave_value ();
}

DEFUN (allow_noninteger_range_as_index, args, nargout,
       "-*- texinfo -*-\n\
@deftypefn  {Built-in Function} {@var{val} =} allow_noninteger_range_as_index ()\n\
@deftypefnx {Built-in Function} {@var{old_val} =} allow_noninteger_range_as_index (@var{new_val})\n\
@deftypefnx {Built-in Function} {} allow_noninteger_range_as_index (@var{new_val}, \"local\")\n\
Query or set the internal variable that controls whether non-integer\n\
ranges are allowed as indices.  This might be useful for @sc{matlab}\n\
compatibility; however, it is still not entirely compatible because\n\
@sc{matlab} treats the range expression differently in different contexts.\n\
\n\
When called from inside a function with the @qcode{\"local\"} option, the\n\
variable is changed locally for the function and any subroutines it calls.  \n\
The original variable value is restored when exiting the function.\n\
@end deftypefn")
{
  static bool warned = false;
  if (! warned)
    {
      warned = true;
      warning_with_id ("Octave:deprecated-function",
                       "allow_noninteger_range_as_index is obsolete and will be removed from a future version of Octave");
    }

  return SET_INTERNAL_VARIABLE (allow_noninteger_range_as_index);
}

/*
%!test
%! x = 0:10;
%! save = allow_noninteger_range_as_index ();
%! warn_state = warning ("query", "Octave:noninteger-range-as-index");
%! unwind_protect
%!   allow_noninteger_range_as_index (false);
%!   fail ("x(2.1:5)");
%!   assert (x(2:5), 1:4);
%!   allow_noninteger_range_as_index (true);
%!   warning ("off", "Octave:noninteger-range-as-index");
%!   assert (x(2.49:5), 1:3);
%!   assert (x(2.5:5), 2:4);
%!   assert (x(2.51:5), 2:4);
%! unwind_protect_cleanup
%!   allow_noninteger_range_as_index (save);
%!   warning (warn_state.state, warn_state.identifier);
%! end_unwind_protect
*/