/*

Copyright (C) 1996, 1997 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 2, 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, write to the Free
Software Foundation, 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.

*/

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

#include <cerrno>
#include <climits>
#include <cstring>

#include <fstream>
#include <iostream>
#include <string>

#ifdef HAVE_UNISTD_H
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <unistd.h>
#endif

// Include setjmp.h, not csetjmp since the latter might only define
// the ANSI standard C interface.

#include <setjmp.h>

#include "dir-ops.h"
#include "file-ops.h"
#include "file-stat.h"
#include "lo-sstream.h"
#include "oct-cmplx.h"
#include "oct-env.h"
#include "pathsearch.h"
#include "str-vec.h"

#include <defaults.h>
#include "defun.h"
#include "dirfns.h"
#include "error.h"
#include "gripes.h"
#include "input.h"
#include "oct-hist.h"
#include "oct-obj.h"
#include "pager.h"
#include "sysdep.h"
#include "toplev.h"
#include "unwind-prot.h"
#include "utils.h"
#include "variables.h"

// Should expressions like ones (-1, 5) result in an empty matrix or
// an error?  A positive value means yes.  A negative value means
// yes, but print a warning message.  Zero means it should be
// considered an error.
static int Vtreat_neg_dim_as_zero;

// Return TRUE if S is a valid identifier.

bool
valid_identifier (const char *s)
{
  if (! s || ! (isalnum (*s) || *s == '_'))
     return false;

  while (*++s != '\0')
    if (! (isalnum (*s) || *s == '_'))
      return false;

  return true;
}

bool
valid_identifier (const std::string& s)
{
  return valid_identifier (s.c_str ());
}

int
almost_match (const std::string& std, const std::string& s, int min_match_len,
	      int case_sens)
{
  int stdlen = std.length ();
  int slen = s.length ();

  return (slen <= stdlen
	  && slen >= min_match_len
	  && (case_sens
	      ? (strncmp (std.c_str (), s.c_str (), slen) == 0)
	      : (octave_strncasecmp (std.c_str (), s.c_str (), slen) == 0)));
}

// Ugh.

int
keyword_almost_match (const char * const *std, int *min_len, const std::string& s,
		      int min_toks_to_match, int max_toks)
{
  int status = 0;
  int tok_count = 0;
  int toks_matched = 0;

  if (s.empty () || max_toks < 1)
    return status;

  char *kw = strsave (s.c_str ());

  char *t = kw;
  while (*t != '\0')
    {
      if (*t == '\t')
	*t = ' ';
      t++;
    }

  char *beg = kw;
  while (*beg == ' ')
    beg++;

  if (*beg == '\0')
    return status;


  const char **to_match = new const char * [max_toks + 1];
  const char * const *s1 = std;
  const char **s2 = to_match;

  if (! s1 || ! s2)
    goto done;

  s2[tok_count] = beg;
  char *end;
  while ((end = strchr (beg, ' ')) != 0)
    {
      *end = '\0';
      beg = end + 1;

      while (*beg == ' ')
	beg++;

      if (*beg == '\0')
	break;

      tok_count++;
      if (tok_count >= max_toks)
	goto done;

      s2[tok_count] = beg;
    }
  s2[tok_count+1] = 0;

  s2 = to_match;

  for (;;)
    {
      if (! almost_match (*s1, *s2, min_len[toks_matched], 0))
	goto done;

      toks_matched++;

      s1++;
      s2++;

      if (! *s2)
	{
	  status = (toks_matched >= min_toks_to_match);
	  goto done;
	}

      if (! *s1)
	goto done;
    }

 done:

  delete [] kw;
  delete [] to_match;

  return status;
}

// Return non-zero if either NR or NC is zero.  Return -1 if this
// should be considered fatal; return 1 if this is ok.

int
empty_arg (const char *name, int nr, int nc)
{
  int is_empty = 0;

  if (nr == 0 || nc == 0)
    {
      int flag = Vpropagate_empty_matrices;

      if (flag < 0)
	{
	  gripe_empty_arg (name, 0);
	  is_empty = 1;
	}
      else if (flag == 0)
	{
	  gripe_empty_arg (name, 1);
	  is_empty = -1;
	}
      else
	is_empty = 1;
    }

  return is_empty;
}

// See if the given file is in the path.

std::string
search_path_for_file (const std::string& path, const std::string& name)
{
  dir_path p (path);

  return octave_env::make_absolute (p.find (name), octave_env::getcwd ());
}

DEFUN (file_in_loadpath, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} file_in_loadpath (@var{name})\n\
\n\
Look up @var{name} in Octave's @code{LOADPATH}.\n\
@end deftypefn\n\
@seealso{file_in_path}")
{
  octave_value_list retval;

  int argc = args.length () + 1;

  string_vector argv = args.make_argv ("file_in_loadpath");

  if (error_state)
    return retval;

  if (argc == 2)
    retval = octave_env::make_absolute (Vload_path_dir_path.find (argv[1]),
					octave_env::getcwd ());
  else
    print_usage ("file_in_loadpath");

  return retval;
}

DEFUN (file_in_path, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} file_in_path (@var{path}, @var{file})\n\
Return the absolute name name of @var{file} if it can be found in\n\
@var{path}.  The value of @var{path} should be a colon-separated list of\n\
directories in the format described for the built-in variable\n\
@code{LOADPATH}.\n\
\n\
If the file cannot be found in the path, an empty matrix is returned.\n\
For example,\n\
\n\
@example\n\
file_in_path (LOADPATH, \"nargchk.m\")\n\
     @result{} \"@value{OCTAVEHOME}/share/octave/2.0/m/general/nargchk.m\"\n\
@end example\n\
@end deftypefn")
{
  octave_value_list retval;

  int argc = args.length () + 1;

  string_vector argv = args.make_argv ("file_in_path");

  if (error_state)
    return retval;

  if (argc == 3)
    {
      std::string fname = search_path_for_file (argv[1], argv[2]);

      if (fname.empty ())
	retval = Matrix ();
      else
	retval = fname;
    }
  else
    print_usage ("file_in_path");

  return retval;
}

std::string
file_in_path (const std::string& name, const std::string& suffix)
{
  std::string nm = name;

  if (! suffix.empty ())
    nm.append (suffix);

  return octave_env::make_absolute (Vload_path_dir_path.find (nm),
				    octave_env::getcwd ());
}

// See if there is an function file in the path.  If so, return the
// full path to the file.

std::string
fcn_file_in_path (const std::string& name)
{
  std::string retval;

  int len = name.length ();
  
  if (len > 0)
    {
      if (len > 2 && name [len - 2] == '.' && name [len - 1] == 'm')
	retval = file_in_path (name, "");
      else
	retval = file_in_path (name, ".m");
    }

  return retval;
}

// See if there is an octave file in the path.  If so, return the
// full path to the file.

std::string
oct_file_in_path (const std::string& name)
{
  std::string retval;

  int len = name.length ();
  
  if (len > 0)
    {
      if (len > 2 && name [len - 4] == '.' && name [len - 3] == 'o'
	  && name [len - 2] == 'c' && name [len - 1] == 't')
	retval = file_in_path (name, "");
      else
	retval = file_in_path (name, ".oct");
    }

  return retval;
}

// Replace backslash escapes in a string with the real values.

std::string
do_string_escapes (const std::string& s)
{
  std::string retval;

  size_t i = 0;
  size_t j = 0;
  size_t len = s.length ();

  retval.resize (len);

  while (j < len)
    {
      if (s[j] == '\\' && j+1 < len)
	{
	  switch (s[++j])
	    {
	    case '0':
	      retval[i] = '\0';
	      break;

	    case 'a':
	      retval[i] = '\a';
	      break;

	    case 'b': // backspace
	      retval[i] = '\b';
	      break;

	    case 'f': // formfeed
	      retval[i] = '\f';
	      break;

	    case 'n': // newline
	      retval[i] = '\n';
	      break;

	    case 'r': // carriage return
	      retval[i] = '\r';
	      break;

	    case 't': // horizontal tab
	      retval[i] = '\t';
	      break;

	    case 'v': // vertical tab
	      retval[i] = '\v';
	      break;

	    case '\\': // backslash
	      retval[i] = '\\';
	      break;

	    case '\'': // quote
	      retval[i] = '\'';
	      break;

	    case '"': // double quote
	      retval[i] = '"';
	      break;

	    default:
	      warning ("unrecognized escape sequence `\\%c' --\
 converting to `%c'", s[j], s[j]);
	      retval[i] = s[j];
	      break;
	    }
	}
      else
	{
	  retval[i] = s[j];
	}

      i++;
      j++;
    }

  retval.resize (i);

  return retval;
}

DEFUN (do_string_escapes, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} do_string_escapes (@var{string})\n\
Convert special characters in @var{string} to their escaped forms.\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 1)
    {
      if (args(0).is_string ())
	retval = do_string_escapes (args(0).string_value ());
      else
	error ("do_string_escapes: argument must be a string");
    }
  else
    print_usage ("do_string_escapes");

  return retval;
}

const char *
undo_string_escape (char c)
{
  if (! c)
    return "";

  switch (c)
    {
    case '\0':
      return "\\0";

    case '\a':
      return "\\a";

    case '\b': // backspace
      return "\\b";

    case '\f': // formfeed
      return "\\f";

    case '\n': // newline
      return "\\n";

    case '\r': // carriage return
      return "\\r";

    case '\t': // horizontal tab
      return "\\t";

    case '\v': // vertical tab
      return "\\v";

    case '\\': // backslash
      return "\\\\";

    case '"': // double quote
      return "\\\"";

    default:
      {
	static char retval[2];
	retval[0] = c;
	retval[1] = '\0';
	return retval;
      }
    }
}

std::string
undo_string_escapes (const std::string& s)
{
  std::string retval;

  for (size_t i = 0; i < s.length (); i++)
    retval.append (undo_string_escape (s[i]));

  return retval;
}

DEFUN (undo_string_escapes, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {} undo_string_escapes (@var{s})\n\
Converts special characters in strings back to their escaped forms.  For\n\
example, the expression\n\
\n\
@example\n\
bell = \"\\a\";\n\
@end example\n\
\n\
@noindent\n\
assigns the value of the alert character (control-g, ASCII code 7) to\n\
the string variable @code{bell}.  If this string is printed, the\n\
system will ring the terminal bell (if it is possible).  This is\n\
normally the desired outcome.  However, sometimes it is useful to be\n\
able to print the original representation of the string, with the\n\
special characters replaced by their escape sequences.  For example,\n\
\n\
@example\n\
octave:13> undo_string_escapes (bell)\n\
ans = \\a\n\
@end example\n\
\n\
@noindent\n\
replaces the unprintable alert character with its printable\n\
representation.\n\
@end deftypefn")
{
  octave_value retval;

  int nargin = args.length ();

  if (nargin == 1)
    {
      if (args(0).is_string ())
	retval = undo_string_escapes (args(0).string_value ());
      else
	error ("undo_string_escapes: argument must be a string");
    }
  else
    print_usage ("undo_string_escapes");

  return retval;
}

// #if 0

// Octave could use some way to access the value of ERRNO, but this is
// probably not the best interface, so don't depend on it...

DEFUN (ERRNO, args, ,
  "-*- texinfo -*-\n\
@deftypefn {Built-in Function} {@var{system_error_number}} errno ()\n\
Return the current value of the system-dependent variable errno.\n\
@end deftypefn")
{
  octave_value retval;

  if (args.length () == 0)
    retval = static_cast<double> (errno);
  else
    print_usage ("errno");

  return retval;
}

// #endif

static void
warn_old_style_preference (bool val, const std::string& sval)
{
  warning
    ("preference of \"%s\" is obsolete -- use numeric value of %d instead",
     sval.c_str (), (val ? 1 : 0));
}

// Check the value of a string variable to see if it it's ok to do
// something.
//
//   return of  1 => always ok.
//   return of  0 => never ok.
//   return of -1 => ok, but give me warning (default).

int
check_preference (const std::string& var)
{
  int pref = -1;

  std::string val = builtin_string_variable (var);

  if (val.empty ())
    {
      double dval = 0;
      if (builtin_real_scalar_variable (var, dval))
	pref = NINT (dval);
    }
  else
    {
      if (val == "yes" || val == "true")
	{
	  warn_old_style_preference (true, val);
	  pref = 1;
	}
      else if (val == "never" || val == "no" || val == "false")
	{
	  warn_old_style_preference (false, val);
	  pref = 0;
	}
    }

  return pref;
}

static void
check_dimensions (int& nr, int& nc, const char *warnfor)
{
  if (nr < 0 || nc < 0)
    {
      if (Vtreat_neg_dim_as_zero)
	{
	  nr = (nr < 0) ? 0 : nr;
	  nc = (nc < 0) ? 0 : nc;

	  if (Vtreat_neg_dim_as_zero < 0)
	    warning ("%s: converting negative dimension to zero",
		     warnfor);
	}
      else
	error ("%s: can't create a matrix with negative dimensions",
	       warnfor);
    }
}

void
get_dimensions (const octave_value& a, const char *warn_for,
		int& nr, int& nc)
{
  if (a.is_scalar_type ())
    {
      nr = nc = a.nint_value ();
    }
  else
    {
      nr = a.rows ();
      nc = a.columns ();

      if ((nr == 1 && nc == 2) || (nr == 2 && nc == 1))
	{
	  Array<double> v = a.vector_value ();

	  if (error_state)
	    return;

	  nr = NINT (v (0));
	  nc = NINT (v (1));
	}
      else
	warning ("%s (A): use %s (size (A)) instead", warn_for, warn_for);
    }

  check_dimensions (nr, nc, warn_for); // May set error_state.
}

void
get_dimensions (const octave_value& a, const octave_value& b,
		const char *warn_for, int& nr, int& nc)
{
  nr = a.is_empty () ? 0 : a.nint_value ();
  nc = b.is_empty () ? 0 : b.nint_value ();

  if (error_state)
    error ("%s: expecting two scalar arguments", warn_for);
  else
    check_dimensions (nr, nc, warn_for); // May set error_state.
}

extern int
octave_format (std::ostream& os, const char *fmt, ...)
{
  int retval = -1;

  va_list args;
  va_start (args, fmt);

  retval = octave_vformat (os, fmt, args);

  va_end (args);

  return retval;
}

extern int
octave_vformat (std::ostream& os, const char *fmt, va_list args)
{
  int retval = -1;

#if defined (__GNUG__) && !CXX_ISO_COMPLIANT_LIBRARY

  std::streambuf *sb = os.rdbuf ();

  if (sb)
    retval = sb->vform (fmt, args);

#else

  char *s = octave_vsnprintf (fmt, args);

  if (s)
    {
      os << s;

      retval = strlen (s);
    }

#endif

  return retval;
}

void
octave_sleep (double seconds)
{
  if (seconds > 0)
    {
      double t;

      unsigned int usec
	= static_cast <unsigned int> (modf (seconds, &t) * 1000000);

      unsigned int sec
	= (t > UINT_MAX) ? UINT_MAX : static_cast <unsigned int> (t);

      octave_sleep (sec);
      octave_usleep (usec);
    }
}

static int
treat_neg_dim_as_zero (void)
{
  Vtreat_neg_dim_as_zero = check_preference ("treat_neg_dim_as_zero");

  return 0;
}

void
symbols_of_utils (void)
{
  DEFVAR (treat_neg_dim_as_zero, 0.0, treat_neg_dim_as_zero,
    "-*- texinfo -*-\n\
@defvr {Built-in Variable} treat_neg_dim_as_zero\n\
If the value of @code{treat_neg_dim_as_zero} is nonzero, expressions\n\
like\n\
\n\
@example\n\
eye (-1)\n\
@end example\n\
\n\
@noindent\n\
produce an empty matrix (i.e., row and column dimensions are zero).\n\
Otherwise, an error message is printed and control is returned to the\n\
top level.  The default value is 0.\n\
@end defvr");
}

/*
;;; Local Variables: ***
;;; mode: C++ ***
;;; End: ***
*/