/* Get the directory for the root of the project tree.  It throws an
   exception if you are not in a project tree.

   Copyright (C) 2001, 2002 Tom Lord
   Copyright (C) 2002, 2003 Walter Landry and the Regents of the
                                  University of California

   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., 59 Temple Place, Suite 330, Boston, MA 02111-1307
   USA */

#include "boost/filesystem/operations.hpp"
#include "arx_error.hpp"

using namespace std;
using namespace boost;
namespace fs=boost::filesystem;
using fs::path;

path tree_root(const path &directory)
{
  if(!directory.empty() && !lexists(directory))
    {
      return tree_root(directory.branch_path());
    }

  path root(system_complete(directory));

  while(!lexists(root / "_arx"))
    {
      if(root.string()=="/")
        {
          throw arx_error("not a project tree\n\t"
                          + directory.native_file_string());
        }
      root=root.branch_path();
    }

  return system_complete(root);
}