# -*- coding: utf-8; Mode: Python; indent-tabs-mode: nil; tab-width: 4 -*-

# Copyright (C) 2006, 2007, 2008 Canonical Ltd.
# Written by Colin Watson <cjwatson@ubuntu.com>.
#
# 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 St, Fifth Floor, Boston, MA  02110-1301  USA

# All these functions check whether gconftool-2 exists, so you may safely
# call them even if gconftool-2 is not guaranteed to be available.

import os
import subprocess

from ubiquity import osextras
from ubiquity import misc

# I think it's clearer to keep our 'set' method, and it doesn't cause a
# builtin-shadowing problem in practice unless you use 'from
# ubiquity.gconftool import set' (so don't do that).
__pychecker__ = 'no-shadowbuiltin'

_cached_gconftool_exists = None
def _gconftool_exists():
    global _cached_gconftool_exists
    if _cached_gconftool_exists is not None:
        return _cached_gconftool_exists

    _cached_gconftool_exists = osextras.find_on_path('gconftool-2')
    return _cached_gconftool_exists

def _gconf_dir():
    if 'SUDO_USER' in os.environ:
        d = os.path.expanduser('~%s/.gconf' % os.environ['SUDO_USER'])
    else:
        d = os.path.expanduser('~/.gconf')
    return 'xml:readwrite:%s' % d

def get(key):
    if not _gconftool_exists():
        return

    subp = subprocess.Popen(['gconftool-2', '--config-source', _gconf_dir(),
                             '--get', key],
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                            preexec_fn=misc.drop_all_privileges)
    return subp.communicate()[0].rstrip('\n')

def get_list(key):
    if not _gconftool_exists():
        return

    gconf_dir = _gconf_dir()
    subp = subprocess.Popen(['gconftool-2', '--config-source', gconf_dir,
                             '--get-list-size', key],
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                            preexec_fn=misc.drop_all_privileges)
    size = subp.communicate()[0].rstrip('\n')
    try:
        size = int(size)
    except ValueError:
        size = 0

    elements = []
    for i in range(size):
        subp = subprocess.Popen(['gconftool-2', '--config-source', gconf_dir,
                                 '--get-list-element', key, str(i)],
                                stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                                preexec_fn=misc.drop_all_privileges)
        elements.append(subp.communicate()[0].rstrip('\n'))

    return elements

def set(key, keytype, value):
    if not _gconftool_exists():
        return

    gconf_dir = _gconf_dir()
    subprocess.call(['gconftool-2', '--config-source', gconf_dir, '--set', key,
                     '--type', keytype, value],
                    preexec_fn=misc.drop_all_privileges)

def unset(key):
    if not _gconftool_exists():
        return

    subprocess.call(['gconftool-2', '--unset', key],
                    preexec_fn=misc.drop_all_privileges)

def _dir_exists(key):
    if not _gconftool_exists():
        return False

    subp = subprocess.Popen(['gconftool-2', '--config-source', _gconf_dir(),
                             '--dir-exists=%s' % key],
                            stdout=subprocess.PIPE, stderr=subprocess.PIPE,
                            preexec_fn=misc.drop_all_privileges)
    subp.communicate()
    if subp.returncode != 0:
        return False
    else:
        return True

def dump(key, f):
    '''Dump the contents of a gconf tree to a file.'''
    # This is fairly specific to the network configuration copying.  If we ever
    # need to do something with the data in Python or need to write the file as
    # root, this function should be modified.

    if not _dir_exists(key):
        return False
    with open(f, 'w') as fp:
        subp = subprocess.Popen(['gconftool-2', '--config-source', _gconf_dir(),
                                 '--dump', key],
                                stdout=fp, stderr=subprocess.PIPE,
                                preexec_fn=misc.drop_all_privileges)
        subp.communicate()
    return True
