/*
    Copyright (C) 2007 by Robert Knight <robertknight@gmail.com>

    Rewritten for QT4 by e_k <e_k at users.sourceforge.net>, Copyright (C)2008

    This program 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 of the License, or
    (at your option) any later version.

    This program 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 this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
    02110-1301  USA.
*/

// Own
#include "ShellCommand.h"

//some versions of gcc(4.3) require explicit include
#include <cstdlib>

// expands environment variables in 'text'
// function copied from kdelibs/kio/kio/kurlcompletion.cpp
static bool expandEnv (QString & text);

ShellCommand::ShellCommand (const QString & fullCommand)
{
  bool inQuotes = false;

  QString builder;

  for (int i = 0; i < fullCommand.count (); i++)
    {
      QChar ch = fullCommand[i];

      const bool isLastChar = (i == fullCommand.count () - 1);
      const bool isQuote = (ch == '\'' || ch == '\"');

      if (!isLastChar && isQuote)
	inQuotes = !inQuotes;
      else
	{
	  if ((!ch.isSpace () || inQuotes) && !isQuote)
	    builder.append (ch);

	  if ((ch.isSpace () && !inQuotes) || (i == fullCommand.count () - 1))
	    {
	      _arguments << builder;
	      builder.clear ();
	    }
	}
    }
}

ShellCommand::ShellCommand (const QString & command,
			    const QStringList & arguments)
{
  _arguments = arguments;

  if (!_arguments.isEmpty ())
    _arguments[0] == command;
}

QString
ShellCommand::fullCommand () const
{
  return _arguments.join (QChar (' '));
}

QString
ShellCommand::command () const
{
  if (!_arguments.isEmpty ())
    return _arguments[0];
  else
    return QString ();
}

QStringList
ShellCommand::arguments () const
{
  return _arguments;
}

bool
ShellCommand::isRootCommand () const
{
  Q_ASSERT (0);			// not implemented yet
  return false;
}

bool
ShellCommand::isAvailable () const
{
  Q_ASSERT (0);			// not implemented yet
  return false;
}

QStringList
ShellCommand::expand (const QStringList & items)
{
  QStringList result;

  foreach (QString item, items) result << expand (item);

  return result;
}

QString
ShellCommand::expand (const QString & text)
{
  QString result = text;
  expandEnv (result);
  return result;
}

/*
 * expandEnv
 *
 * Expand environment variables in text. Escaped '$' characters are ignored.
 * Return true if any variables were expanded
 */
static bool
expandEnv (QString & text)
{
  // Find all environment variables beginning with '$'
  //
  int pos = 0;

  bool expanded = false;

  while ((pos = text.indexOf (QLatin1Char ('$'), pos)) != -1)
    {

      // Skip escaped '$'
      //
      if (pos > 0 && text.at (pos - 1) == QLatin1Char ('\\'))
	{
	  pos++;
	}
      // Variable found => expand
      //
      else
	{
	  // Find the end of the variable = next '/' or ' '
	  //
	  int pos2 = text.indexOf (QLatin1Char (' '), pos + 1);
	  int pos_tmp = text.indexOf (QLatin1Char ('/'), pos + 1);

	  if (pos2 == -1 || (pos_tmp != -1 && pos_tmp < pos2))
	    pos2 = pos_tmp;

	  if (pos2 == -1)
	    pos2 = text.length ();

	  // Replace if the variable is terminated by '/' or ' '
	  // and defined
	  //
	  if (pos2 >= 0)
	    {
	      int len = pos2 - pos;
	      QString key = text.mid (pos + 1, len - 1);
	      QString value =
		QString::fromLocal8Bit (::getenv (key.toLocal8Bit ()));

	      if (!value.isEmpty ())
		{
		  expanded = true;
		  text.replace (pos, len, value);
		  pos = pos + value.length ();
		}
	      else
		{
		  pos = pos2;
		}
	    }
	}
    }

  return expanded;
}