/* Copyright © 2003,2006-2008  Roger Leigh <rleigh@debian.org>
 *
 * schroot 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.
 *
 * schroot 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, see
 * <http://www.gnu.org/licenses/>.
 *
 *********************************************************************/

#include <config.h>

#include "sbuild-mntstream.h"

#include <cerrno>
#include <cstring>

using namespace sbuild;

namespace
{

  typedef std::pair<mntstream::error_code,const char *> emap;

  /**
   * This is a list of the supported error codes.  It's used to
   * construct the real error codes map.
   */
  emap init_errors[] =
    {
      // TRANSLATORS: %1% = mount file name
      emap(mntstream::MNT_OPEN,    N_("Failed to open mount file '%1%'")),
      // TRANSLATORS: %1% = mount file name
      emap(mntstream::MNT_READ,    N_("Failed to read mount file '%1%'"))
    };

}

template<>
error<mntstream::error_code>::map_type
error<mntstream::error_code>::error_strings
(init_errors,
 init_errors + (sizeof(init_errors) / sizeof(init_errors[0])));


mntstream::mntentry::mntentry (struct mntent const&  entry):
  filesystem_name(entry.mnt_fsname),
  directory(entry.mnt_dir),
  type(entry.mnt_type),
  options(entry.mnt_opts),
  dump_frequency(entry.mnt_freq),
  fsck_pass(entry.mnt_passno)
{
}


mntstream::mntstream(std::string const& file):
  file(),
  mntfile(0),
  data(),
  error_status(true),
  eof_status(true)
{
  open(file);
}


mntstream::~mntstream()
{
  close();
}

void
mntstream::open(std::string const& file)
{
  this->mntfile = setmntent(file.c_str(), "r");
  if (this->mntfile == 0)
    {
      this->file.clear();
      this->error_status = true;
      this->eof_status = true;
      throw error(file, MNT_OPEN, strerror(errno));
    }
  this->file = file;
  this->error_status = false;
  this->eof_status = false;
  read();
}

void
mntstream::read(int quantity)
{
  int i;

  if (this->mntfile == 0)
    return;

  for (i = 0; i < quantity; ++i)
    {
      struct mntent* entry;
      errno = 0;
      entry = getmntent(mntfile);

      if (entry == 0) // EOF or error
	{
	  //std::cerr << "Mount file read error: ";
	  if (errno) // error
	    {
	      this->error_status = true;
	      throw error(this->file, MNT_READ, strerror(errno));
	    }
	  return;
	}

      mntentry newentry(*entry); // make a mntentry
      this->data.push_back(newentry); // push onto the end of the list
    }
}

void
mntstream::close()
{
  if (this->mntfile)
    endmntent(this->mntfile); // don't throw an exception on failure
			      // -- it could be called in the
			      // destructor
  this->mntfile = 0;
  this->data.clear();    // clear all data
  this->file.clear();
  this->error_status = true;
  this->eof_status = true;
}


bool
mntstream::eof() const
{
  return this->eof_status;
}

bool
mntstream::bad() const
{
  return this->error_status;
}

mntstream::operator bool ()
{
  return !(bad() || eof());
}

bool
mntstream::operator ! ()
{
  return bad() || eof();
}


mntstream&
sbuild::operator >> (mntstream&            stream,
		     mntstream::mntentry&  entry)
{
  stream.read(); // read a new entry
  if (stream && !stream.data.empty()) // not at end of file or bad.
    {
      entry = stream.data.front(); // assign next mntentry to entry
      stream.data.pop_front(); // remove the entry
    }
  else // blank the mntentry and set EOF status
    {
      entry = mntstream::mntentry();
      stream.eof_status = true;
    }

  return stream;
}