/*

Copyright (C) 2008-2012 David Bateman

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 <algorithm>

#include "defun.h"
#include "error.h"
#include "gripes.h"
#include "oct-obj.h"
#include "utils.h"

DEFUN (hex2num, args, ,
  "-*- texinfo -*-\n\
@deftypefn  {Built-in Function} {@var{n} =} hex2num (@var{s})\n\
@deftypefnx {Built-in Function} {@var{n} =} hex2num (@var{s}, @var{class})\n\
Typecast the 16 character hexadecimal character string to an IEEE 754\n\
double precision number.  If fewer than 16 characters are given the\n\
strings are right padded with '0' characters.\n\
\n\
Given a string matrix, @code{hex2num} treats each row as a separate\n\
number.\n\
\n\
@example\n\
@group\n\
hex2num ([\"4005bf0a8b145769\"; \"4024000000000000\"])\n\
   @result{} [2.7183; 10.000]\n\
@end group\n\
@end example\n\
\n\
The optional argument @var{class} can be passed as the string \"single\" to\n\
specify that the given string should be interpreted as a single precision\n\
number.  In this case, @var{s} should be an 8 character hexadecimal string.\n\
For example:\n\
@example\n\
@group\n\
hex2num ([\"402df854\"; \"41200000\"], \"single\")\n\
   @result{} [2.7183; 10.000]\n\
@end group\n\
@end example\n\
@seealso{num2hex, hex2dec, dec2hex}\n\
@end deftypefn")
{
  int nargin = args.length ();
  octave_value retval;

  if (nargin < 1 || nargin > 2)
    print_usage ();
  else if (nargin == 2 && ! args(1).is_string ())
    error ("hex2num: CLASS must be a string");
  else
    {
      const charMatrix cmat = args(0).char_matrix_value ();
      std::string prec = (nargin == 2) ? args(1).string_value () : "double";
      bool is_single = (prec == "single");
      octave_idx_type nchars = (is_single) ? 8 : 16;

      if (cmat.columns () > nchars)
        error ("hex2num: S must be no more than %d characters", nchars);
      else if (prec != "double" && prec != "single")
        error ("hex2num: CLASS must be either \"double\" or \"single\"");
      else if (! error_state)
        {
          octave_idx_type nr = cmat.rows ();
          octave_idx_type nc = cmat.columns ();

          if (is_single)
            {
              FloatColumnVector m (nr);

              for (octave_idx_type i = 0; i < nr; i++)
                {
                  union
                  {
                    uint32_t ival;
                    float dval;
                  } num;

                  num.ival = 0;

                  for (octave_idx_type j = 0; j < nc; j++)
                    {
                      unsigned char ch = cmat.elem (i, j);

                      if (isxdigit (ch))
                        {
                          num.ival <<= 4;
                          if (ch >= 'a')
                            num.ival += static_cast<uint32_t> (ch - 'a' + 10);
                          else if (ch >= 'A')
                            num.ival += static_cast<uint32_t> (ch - 'A' + 10);
                          else
                            num.ival += static_cast<uint32_t> (ch - '0');
                        }
                      else
                        {
                          error ("hex2num: illegal character found in string S");
                          break;
                        }
                    }

                  if (error_state)
                    break;
                  else
                    {
                      if (nc < nchars)
                        num.ival <<= (nchars - nc) * 4;

                      m(i) = num.dval;
                    }
                }

              if (! error_state)
                retval =  m;
            }
          else
            {
              ColumnVector m (nr);

              for (octave_idx_type i = 0; i < nr; i++)
                {
                  union
                  {
                    uint64_t ival;
                    double dval;
                  } num;

                  num.ival = 0;

                  for (octave_idx_type j = 0; j < nc; j++)
                    {
                      unsigned char ch = cmat.elem (i, j);

                      if (isxdigit (ch))
                        {
                          num.ival <<= 4;
                          if (ch >= 'a')
                            num.ival += static_cast<uint64_t> (ch - 'a' + 10);
                          else if (ch >= 'A')
                            num.ival += static_cast<uint64_t> (ch - 'A' + 10);
                          else
                            num.ival += static_cast<uint64_t> (ch - '0');
                        }
                      else
                        {
                          error ("hex2num: illegal character found in string S");
                          break;
                        }
                    }

                  if (error_state)
                    break;
                  else
                    {
                      if (nc < nchars)
                        num.ival <<= (nchars - nc) * 4;

                      m(i) = num.dval;
                    }
                }

              if (! error_state)
                retval =  m;
            }
        }
    }

  return retval;
}

/*
%!assert (hex2num (["c00";"bff";"000";"3ff";"400"]), [-2:2]')
%!assert (hex2num (["c00";"bf8";"000";"3f8";"400"], "single"), single([-2:2])')
*/

DEFUN (num2hex, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {@var{s} =} num2hex (@var{n})\n\
Typecast a double or single precision number or vector to a 8 or 16\n\
character hexadecimal string of the IEEE 754 representation of the number.\n\
For example:\n\
\n\
@example\n\
@group\n\
num2hex ([-1, 1, e, Inf])\n\
@result{} \"bff0000000000000\n\
    3ff0000000000000\n\
    4005bf0a8b145769\n\
    7ff0000000000000\"\n\
@end group\n\
@end example\n\
\n\
If the argument @var{n} is a single precision number or vector, the returned\n\
string has a length of 8.  For example:\n\
\n\
@example\n\
@group\n\
num2hex (single ([-1, 1, e, Inf]))\n\
@result{} \"bf800000\n\
    3f800000\n\
    402df854\n\
    7f800000\"\n\
@end group\n\
@end example\n\
@seealso{hex2num, hex2dec, dec2hex}\n\
@end deftypefn")
{
  int nargin = args.length ();
  octave_value retval;

  if (nargin != 1)
    print_usage ();
  else if (args(0).is_single_type ())
    {
      const FloatColumnVector v (args(0).float_vector_value ());

      if (! error_state)
        {
          octave_idx_type nchars = 8;
          octave_idx_type nr = v.length ();
          charMatrix m (nr, nchars);
          const float *pv = v.fortran_vec ();

          for (octave_idx_type i = 0; i < nr; i++)
            {
              union
              {
                uint32_t ival;
                float dval;
              } num;

              num.dval = *pv++;

              for (octave_idx_type j = 0; j < nchars; j++)
                {
                  unsigned char ch =
                    static_cast<char> (num.ival >> ((nchars - 1 - j) * 4) & 0xF);
                  if (ch >= 10)
                    ch += 'a' - 10;
                  else
                    ch += '0';

                  m.elem (i, j) = ch;
                }
            }

          retval = m;
        }
    }
  else
    {
      const ColumnVector v (args(0).vector_value ());

      if (! error_state)
        {
          octave_idx_type nchars = 16;
          octave_idx_type nr = v.length ();
          charMatrix m (nr, nchars);
          const double *pv = v.fortran_vec ();

          for (octave_idx_type i = 0; i < nr; i++)
            {
              union
              {
                uint64_t ival;
                double dval;
              } num;

              num.dval = *pv++;

              for (octave_idx_type j = 0; j < nchars; j++)
                {
                  unsigned char ch =
                    static_cast<char> (num.ival >> ((nchars - 1 - j) * 4) & 0xF);
                  if (ch >= 10)
                    ch += 'a' - 10;
                  else
                    ch += '0';

                  m.elem (i, j) = ch;
                }
            }

          retval = m;
        }
    }

  return retval;
}

/*
%!assert (num2hex (-2:2), ["c000000000000000";"bff0000000000000";"0000000000000000";"3ff0000000000000";"4000000000000000"])
%!assert (num2hex (single (-2:2)), ["c0000000";"bf800000";"00000000";"3f800000";"40000000"])
*/