/*

Copyright (C) 1994-2015 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 <cerrno>
#include <cstdio>
#include <cstddef>
#include <cstdlib>
#include <cstring>

#include <sstream>
#include <string>

#include <sys/types.h>
#include <unistd.h>

#include "file-ops.h"
#include "file-stat.h"
#include "glob-match.h"
#include "oct-env.h"
#include "pathsearch.h"
#include "str-vec.h"

#include "Cell.h"
#include "defun.h"
#include "dir-ops.h"
#include "dirfns.h"
#include "error.h"
#include "errwarn.h"
#include "input.h"
#include "load-path.h"
#include "octave-link.h"
#include "ovl.h"
#include "pager.h"
#include "procstream.h"
#include "sysdep.h"
#include "toplev.h"
#include "unwind-prot.h"
#include "utils.h"
#include "variables.h"

// TRUE means we ask for confirmation before recursively removing a
// directory tree.
static bool Vconfirm_recursive_rmdir = true;

// The time we last time we changed directories.
octave_time Vlast_chdir_time = 0.0;

static int
octave_change_to_directory (const std::string& newdir)
{
  std::string xdir = file_ops::tilde_expand (newdir);

  int cd_ok = octave_env::chdir (xdir);

  if (! cd_ok)
    error ("%s: %s", newdir.c_str (), gnulib::strerror (errno));

  Vlast_chdir_time.stamp ();

  // FIXME: should these actions be handled as a list of functions
  // to call so users can add their own chdir handlers?

  load_path::update ();

  octave_link::change_directory (octave_env::get_current_directory ());

  return cd_ok;
}

DEFUN (cd, args, nargout,
       "-*- texinfo -*-\n\
@deftypefn  {} {} cd @var{dir}\n\
@deftypefnx {} {} cd\n\
@deftypefnx {} {@var{old_dir} =} cd (@var{dir})\n\
@deftypefnx {} {} chdir @dots{}\n\
Change the current working directory to @var{dir}.\n\
\n\
If @var{dir} is omitted, the current directory is changed to the user's home\n\
directory (@qcode{\"~\"}).\n\
\n\
For example,\n\
\n\
@example\n\
cd ~/octave\n\
@end example\n\
\n\
@noindent\n\
changes the current working directory to @file{~/octave}.  If the\n\
directory does not exist, an error message is printed and the working\n\
directory is not changed.\n\
\n\
@code{chdir} is an alias for @code{cd} and can be used in all of the same\n\
calling formats.\n\
\n\
Compatibility Note: When called with no arguments, @sc{matlab} prints the\n\
present working directory rather than changing to the user's home directory.\n\
@seealso{pwd, mkdir, rmdir, dir, ls}\n\
@end deftypefn")
{
  int nargin = args.length ();

  if (nargin > 1)
    print_usage ();

  octave_value_list retval;

  if (nargout > 0)
    retval = octave_value (octave_env::get_current_directory ());

  if (nargin == 1)
    {
      std::string dirname = args(0).xstring_value ("cd: DIR must be a string");

      if (! dirname.empty ())
        octave_change_to_directory (dirname);
    }
  else
    {
      std::string home_dir = octave_env::get_home_directory ();

      if (! home_dir.empty ())
        octave_change_to_directory (home_dir);
    }

  return retval;
}

DEFALIAS (chdir, cd);

DEFUN (pwd, , ,
       "-*- texinfo -*-\n\
@deftypefn  {} {} pwd ()\n\
@deftypefnx {} {@var{dir} =} pwd ()\n\
Return the current working directory.\n\
@seealso{cd, dir, ls, mkdir, rmdir}\n\
@end deftypefn")
{
  return ovl (octave_env::get_current_directory ());
}

DEFUN (readdir, args, ,
       "-*- texinfo -*-\n\
@deftypefn  {} {@var{files} =} readdir (@var{dir})\n\
@deftypefnx {} {[@var{files}, @var{err}, @var{msg}] =} readdir (@var{dir})\n\
Return the names of files in the directory @var{dir} as a cell array of\n\
strings.\n\
\n\
If an error occurs, return an empty cell array in @var{files}.\n\
If successful, @var{err} is 0 and @var{msg} is an empty string.\n\
Otherwise, @var{err} is nonzero and @var{msg} contains a system-dependent\n\
error message.\n\
@seealso{ls, dir, glob, what}\n\
@end deftypefn")
{
  if (args.length () != 1)
    print_usage ();

  std::string dirname = args(0).xstring_value ("readdir: DIR must be a string");

  octave_value_list retval = ovl (Cell (), -1.0, "");

  dir_entry dir (dirname);

  if (dir)
    {
      string_vector dirlist = dir.read ();
      retval(0) = Cell (dirlist.sort ());
      retval(1) = 0.0;
    }
  else
    retval(2) = dir.error ();

  return retval;
}

// FIXME: should maybe also allow second arg to specify mode?
//        OTOH, that might cause trouble with compatibility later...

DEFUNX ("mkdir", Fmkdir, args, ,
        "-*- texinfo -*-\n\
@deftypefn  {} {} mkdir @var{dir}\n\
@deftypefnx {} {} mkdir (@var{parent}, @var{dir})\n\
@deftypefnx {} {[@var{status}, @var{msg}, @var{msgid}] =} mkdir (@dots{})\n\
Create a directory named @var{dir} in the directory @var{parent}.\n\
\n\
If no @var{parent} directory is specified the present working directory is\n\
used.\n\
\n\
If successful, @var{status} is 1, and @var{msg}, @var{msgid} are empty\n\
character strings ("").  Otherwise, @var{status} is 0, @var{msg} contains a\n\
system-dependent error message, and @var{msgid} contains a unique message\n\
identifier.\n\
\n\
When creating a directory permissions will be set to\n\
@code{0777 - @var{umask}}.\n\
@seealso{rmdir, pwd, cd, umask}\n\
@end deftypefn")
{
  int nargin = args.length ();

  if (nargin < 1 || nargin > 2)
    print_usage ();

  std::string dirname;

  if (nargin == 2)
    {
      std::string parent = args(0).xstring_value ("mkdir: PARENT must be a string");
      std::string dir = args(1).xstring_value ("mkdir: DIR must be a string");

      dirname = file_ops::concat (parent, dir);
    }
  else if (nargin == 1)
    dirname = args(0).xstring_value ("mkdir: DIR must be a string");

  dirname = file_ops::tilde_expand (dirname);

  file_stat fs (dirname);

  if (fs && fs.is_dir ())
    {
      // For Matlab compatibility, return true when directory already exists.
      return ovl (true, "directory exists", "mkdir");
    }
  else
    {
      std::string msg;

      int status = octave_mkdir (dirname, 0777, msg);

      if (status < 0)
        return ovl (false, msg, "mkdir");
      else
        return ovl (true, "", "");
    }
}

DEFUNX ("rmdir", Frmdir, args, ,
        "-*- texinfo -*-\n\
@deftypefn  {} {} rmdir @var{dir}\n\
@deftypefnx {} {} rmdir (@var{dir}, \"s\")\n\
@deftypefnx {} {[@var{status}, @var{msg}, @var{msgid}] =} rmdir (@dots{})\n\
Remove the directory named @var{dir}.\n\
\n\
If the optional second parameter is supplied with value @qcode{\"s\"},\n\
recursively remove all subdirectories as well.\n\
\n\
If successful, @var{status} is 1, and @var{msg}, @var{msgid} are empty\n\
character strings ("").  Otherwise, @var{status} is 0, @var{msg} contains a\n\
system-dependent error message, and @var{msgid} contains a unique message\n\
identifier.\n\
\n\
@seealso{mkdir, confirm_recursive_rmdir, pwd}\n\
@end deftypefn")
{
  int nargin = args.length ();

  if (nargin < 1 || nargin > 2)
    print_usage ();

  std::string dirname = args(0).xstring_value ("rmdir: DIR must be a string");

  std::string fulldir = file_ops::tilde_expand (dirname);
  int status = -1;
  std::string msg;

  if (nargin == 2)
    {
      if (args(1).string_value () != "s")
        error ("rmdir: second argument must be \"s\" for recursive removal");

      bool doit = true;

      if (interactive && ! forced_interactive && Vconfirm_recursive_rmdir)
        {
          std::string prompt = "remove entire contents of " + fulldir + "? ";

          doit = octave_yes_or_no (prompt);
        }

      if (doit)
        status = octave_recursive_rmdir (fulldir, msg);
    }
  else
    status = octave_rmdir (fulldir, msg);

  if (status < 0)
    return ovl (false, msg, "rmdir");
  else
    return ovl (true, "", "");
}

DEFUNX ("link", Flink, args, ,
        "-*- texinfo -*-\n\
@deftypefn  {} {} link @var{old} @var{new}\n\
@deftypefnx {} {[@var{err}, @var{msg}] =} link (@var{old}, @var{new})\n\
Create a new link (also known as a hard link) to an existing file.\n\
\n\
If successful, @var{err} is 0 and @var{msg} is an empty string.\n\
Otherwise, @var{err} is nonzero and @var{msg} contains a system-dependent\n\
error message.\n\
@seealso{symlink, unlink, readlink, lstat}\n\
@end deftypefn")
{
  if (args.length () != 2)
    print_usage ();

  std::string from = args(0).xstring_value ("link: OLD must be a string");
  std::string to = args(1).xstring_value ("link: NEW must be a string");

  std::string msg;

  int status = octave_link (from, to, msg);

  if (status < 0)
    return ovl (-1.0, msg);
  else
    return ovl (status, "");
}

DEFUNX ("symlink", Fsymlink, args, ,
        "-*- texinfo -*-\n\
@deftypefn  {} {} symlink @var{old} @var{new}\n\
@deftypefnx {} {[@var{err}, @var{msg}] =} symlink (@var{old}, @var{new})\n\
Create a symbolic link @var{new} which contains the string @var{old}.\n\
\n\
If successful, @var{err} is 0 and @var{msg} is an empty string.\n\
Otherwise, @var{err} is nonzero and @var{msg} contains a system-dependent\n\
error message.\n\
@seealso{link, unlink, readlink, lstat}\n\
@end deftypefn")
{
  if (args.length () != 2)
    print_usage ();

  std::string from = args(0).xstring_value ("symlink: OLD must be a string");
  std::string to = args(1).xstring_value ("symlink: NEW must be a string");

  std::string msg;

  int status = octave_symlink (from, to, msg);

  if (status < 0)
    return ovl (-1.0, msg);
  else
    return ovl (status, "");
}

DEFUNX ("readlink", Freadlink, args, ,
        "-*- texinfo -*-\n\
@deftypefn  {} {} readlink @var{symlink}\n\
@deftypefnx {} {[@var{result}, @var{err}, @var{msg}] =} readlink (@var{symlink})\n\
Read the value of the symbolic link @var{symlink}.\n\
\n\
If successful, @var{result} contains the contents of the symbolic link\n\
@var{symlink}, @var{err} is 0, and @var{msg} is an empty string.\n\
Otherwise, @var{err} is nonzero and @var{msg} contains a system-dependent\n\
error message.\n\
@seealso{lstat, symlink, link, unlink, delete}\n\
@end deftypefn")
{
  if (args.length () != 1)
    print_usage ();

  std::string symlink = args(0).xstring_value ("readlink: SYMLINK must be a string");

  std::string result, msg;

  int status = octave_readlink (symlink, result, msg);

  if (status < 0)
    return ovl ("", -1.0, msg);
  else
    return ovl (result, status, "");
}

DEFUNX ("rename", Frename, args, ,
        "-*- texinfo -*-\n\
@deftypefn  {} {} rename @var{old} @var{new}\n\
@deftypefnx {} {[@var{err}, @var{msg}] =} rename (@var{old}, @var{new})\n\
Change the name of file @var{old} to @var{new}.\n\
\n\
If successful, @var{err} is 0 and @var{msg} is an empty string.\n\
Otherwise, @var{err} is nonzero and @var{msg} contains a system-dependent\n\
error message.\n\
@seealso{movefile, copyfile, ls, dir}\n\
@end deftypefn")
{
  if (args.length () != 2)
    print_usage ();

  std::string from = args(0).xstring_value ("rename: OLD must be a string");
  std::string to = args(1).xstring_value ("rename: NEW must be a string");

  std::string msg;

  int status = octave_rename (from, to, msg);

  if (status < 0)
    return ovl (-1.0, msg);
  else
    return ovl (status, "");
}

DEFUN (glob, args, ,
       "-*- texinfo -*-\n\
@deftypefn {} {} glob (@var{pattern})\n\
Given an array of pattern strings (as a char array or a cell array) in\n\
@var{pattern}, return a cell array of filenames that match any of\n\
them, or an empty cell array if no patterns match.\n\
\n\
The pattern strings are interpreted as filename globbing patterns (as they\n\
are used by Unix shells).\n\
\n\
Within a pattern\n\
\n\
@table @code\n\
@item *\n\
matches any string, including the null string,\n\
\n\
@item ?\n\
matches any single character, and\n\
\n\
@item [@dots{}]\n\
matches any of the enclosed characters.\n\
@end table\n\
\n\
Tilde expansion is performed on each of the patterns before looking for\n\
matching filenames.  For example:\n\
\n\
@example\n\
ls\n\
   @result{}\n\
      file1  file2  file3  myfile1 myfile1b\n\
glob (\"*file1\")\n\
   @result{}\n\
      @{\n\
        [1,1] = file1\n\
        [2,1] = myfile1\n\
      @}\n\
glob (\"myfile?\")\n\
   @result{}\n\
      @{\n\
        [1,1] = myfile1\n\
      @}\n\
glob (\"file[12]\")\n\
   @result{}\n\
      @{\n\
        [1,1] = file1\n\
        [2,1] = file2\n\
      @}\n\
@end example\n\
@seealso{ls, dir, readdir, what}\n\
@end deftypefn")
{
  if (args.length () != 1)
    print_usage ();

  string_vector pat = args(0).xstring_vector_value ("glob: PATTERN must be a string");

  glob_match pattern (file_ops::tilde_expand (pat));

  return ovl (Cell (pattern.glob ()));
}

/*
%!test
%! tmpdir = tempname;
%! filename = {"file1", "file2", "file3", "myfile1", "myfile1b"};
%! if (mkdir (tmpdir))
%!   cwd = pwd;
%!   cd (tmpdir);
%!   if (strcmp (canonicalize_file_name (pwd), canonicalize_file_name (tmpdir)))
%!     a = 0;
%!     for n = 1:5
%!       save (filename{n}, "a");
%!     endfor
%!   else
%!     rmdir (tmpdir);
%!     error ("Couldn't change to temporary dir");
%!   endif
%! else
%!   error ("Couldn't create temporary directory");
%! endif
%! result1 = glob ("*file1");
%! result2 = glob ("myfile?");
%! result3 = glob ("file[12]");
%! for n = 1:5
%!   delete (filename{n});
%! endfor
%! cd (cwd);
%! rmdir (tmpdir);
%! assert (result1, {"file1"; "myfile1"});
%! assert (result2, {"myfile1"});
%! assert (result3, {"file1"; "file2"});
*/

DEFUN (__fnmatch__, args, ,
       "-*- texinfo -*-\n\
@deftypefn {} {} fnmatch (@var{pattern}, @var{string})\n\
Return true or false for each element of @var{string} that matches any of\n\
the elements of the string array @var{pattern}, using the rules of\n\
filename pattern matching.\n\
\n\
For example:\n\
\n\
@example\n\
@group\n\
fnmatch (\"a*b\", @{\"ab\"; \"axyzb\"; \"xyzab\"@})\n\
     @result{} [ 1; 1; 0 ]\n\
@end group\n\
@end example\n\
@seealso{glob, regexp}\n\
@end deftypefn")
{
  if (args.length () != 2)
    print_usage ();

  string_vector pat = args(0).string_vector_value ();
  string_vector str = args(1).string_vector_value ();

  glob_match pattern (file_ops::tilde_expand (pat));

  return ovl (pattern.match (str));
}

DEFUN (filesep, args, ,
       "-*- texinfo -*-\n\
@deftypefn  {} {} filesep ()\n\
@deftypefnx {} {} filesep (\"all\")\n\
Return the system-dependent character used to separate directory names.\n\
\n\
If @qcode{\"all\"} is given, the function returns all valid file separators\n\
in the form of a string.  The list of file separators is system-dependent.\n\
It is @samp{/} (forward slash) under UNIX or @w{Mac OS X}, @samp{/} and\n\
@samp{\\} (forward and backward slashes) under Windows.\n\
@seealso{pathsep}\n\
@end deftypefn")
{
  int nargin = args.length ();

  if (nargin > 1)
    print_usage ();

  octave_value retval;

  if (nargin == 0)
    retval = file_ops::dir_sep_str ();
  else
    {
      std::string s = args(0).xstring_value ("filesep: argument must be a string");
      if (s != "all")
        error ("filesep: argument must be \"all\"");

      retval = file_ops::dir_sep_chars ();
    }

  return retval;
}

DEFUN (pathsep, args, nargout,
       "-*- texinfo -*-\n\
@deftypefn  {} {@var{val} =} pathsep ()\n\
@deftypefnx {} {@var{old_val} =} pathsep (@var{new_val})\n\
Query or set the character used to separate directories in a path.\n\
@seealso{filesep}\n\
@end deftypefn")
{
  int nargin = args.length ();

  if (nargin > 1)
    print_usage ();

  octave_value retval;

  if (nargout > 0 || nargin == 0)
    retval = dir_path::path_sep_str ();

  if (nargin == 1)
    {
      std::string sval = args(0).xstring_value ("pathsep: argument must be a single character");

      switch (sval.length ())
        {
        case 1:
          dir_path::path_sep_char (sval[0]);
          break;

        case 0:
          dir_path::path_sep_char ('\0');
          break;

        default:
          error ("pathsep: argument must be a single character");
          break;
        }
    }

  return retval;
}

DEFUN (confirm_recursive_rmdir, args, nargout,
       "-*- texinfo -*-\n\
@deftypefn  {} {@var{val} =} confirm_recursive_rmdir ()\n\
@deftypefnx {} {@var{old_val} =} confirm_recursive_rmdir (@var{new_val})\n\
@deftypefnx {} {} confirm_recursive_rmdir (@var{new_val}, \"local\")\n\
Query or set the internal variable that controls whether Octave\n\
will ask for confirmation before recursively removing a directory tree.\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\
@seealso{rmdir}\n\
@end deftypefn")
{
  return SET_INTERNAL_VARIABLE (confirm_recursive_rmdir);
}