# Authors:
#   Rob Crittenden <rcritten@redhat.com>
#   Pavel Zuna <pzuna@redhat.com>
#
# Copyright (C) 2009  Red Hat
# see file 'COPYING' for use and warranty information
#
# 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; version 2 only
#
# 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
"""
Groups of users

Manage groups of users. By default new groups are not Posix groups.
You can mark it as Posix at creation time with the --posix flag and
can promose a non-Posix group using the --posix flag in group-mod.
Once a group is a Posix group there is no way to undo this.

Every group must have a description.

Posix groups must have a group id number (gid). Changing a gid is
supported but can have impact on your file permissions.

EXAMPLES:

 Add a new group:
   ipa group-add --desc='local administrators' localadmins

 Add a new posix group:
   ipa group-add --posix --desc='remote administrators' remoteadmins

 Promote a non-posix group to posix:
   ipa group-mod --posix localadmins

 Create a group with a specific group ID number"
   ipa group-add --posix --gid=500 --desc='unix admins' unixadmins

 Remove a group:
   ipa group-del unixadmins

 Manage group membership, nested groups:
   ipa group-add-member --groups=remoteadmins localadmins

 Manage group membership, users:
   ipa group-add-member --users=test1,test2 localadmins

 Manage group membership, users:
   ipa group-remove-member --users=test2 localadmins

 Show a group:
   ipa group-show localadmins
"""

from ipalib import api
from ipalib import Int, Str
from ipalib.plugins.baseldap import *
from ipalib import _, ngettext


class group(LDAPObject):
    """
    Group object.
    """
    container_dn = api.env.container_group
    object_name = 'group'
    object_name_plural = 'groups'
    object_class = ['ipausergroup']
    object_class_config = 'ipagroupobjectclasses'
    search_attributes_config = 'ipagroupsearchfields'
    default_attributes = [
        'cn', 'description', 'gidnumber', 'member', 'memberof'
    ]
    uuid_attribute = 'ipauniqueid'
    attribute_members = {
        'member': ['user', 'group'],
        'memberof': ['group', 'netgroup', 'rolegroup', 'taskgroup'],
    }

    label = _('User Groups')

    takes_params = (
        Str('cn',
            pattern='^[a-zA-Z0-9_.][a-zA-Z0-9_.-]{0,30}[a-zA-Z0-9_.$-]?$',
            pattern_errmsg='may only include letters, numbers, _, -, . and $',
            maxlength=33,
            cli_name='name',
            label=_('Group name'),
            primary_key=True,
            normalizer=lambda value: value.lower(),
        ),
        Str('description',
            cli_name='desc',
            label=_('Description'),
            doc=_('Group description'),
        ),
        Int('gidnumber?',
            cli_name='gid',
            label=_('GID'),
            doc=_('GID (use this option to set it manually)'),
        ),
        Str('member_group?',
            label=_('Member groups'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
        Str('member_user?',
            label=_('Member users'),
            flags=['no_create', 'no_update', 'no_search'],
        ),
    )

api.register(group)


class group_add(LDAPCreate):
    """
    Create new group.
    """

    msg_summary = _('Added group "%(value)s"')

    takes_options = LDAPCreate.takes_options + (
        Flag('posix',
             cli_name='posix',
             doc=_('Create as posix group?'),
        ),
    )

    def pre_callback(self, ldap, dn, entry_attrs, attrs_list, *keys, **options):
        if options['posix'] or 'gidnumber' in options:
            entry_attrs['objectclass'].append('posixgroup')
            if not 'gidnumber' in options:
                entry_attrs['gidnumber'] = 999
        return dn


api.register(group_add)


class group_del(LDAPDelete):
    """
    Delete group.
    """

    msg_summary = _('Deleted group "%(value)s"')

    def pre_callback(self, ldap, dn, *keys, **options):
        config = ldap.get_ipa_config()[1]
        def_primary_group = config.get('ipadefaultprimarygroup', '')
        def_primary_group_dn = group_dn = self.obj.get_dn(def_primary_group)
        if dn == def_primary_group_dn:
            raise errors.DefaultGroup()
        (group_dn, group_attrs) = ldap.get_entry(dn)
        if 'mepmanagedby' in group_attrs:
            raise errors.ManagedGroupError()
        return dn

    def post_callback(self, ldap, dn, *keys, **options):
        try:
            api.Command['pwpolicy_del'](keys[-1])
        except errors.NotFound:
            pass

        return True

api.register(group_del)


class group_mod(LDAPUpdate):
    """
    Modify group.
    """

    msg_summary = _('Modified group "%(value)s"')

    takes_options = LDAPUpdate.takes_options + (
        Flag('posix',
             cli_name='posix',
             doc=_('change to posix group'),
        ),
    )

    def pre_callback(self, ldap, dn, entry_attrs, *keys, **options):
        if options['posix'] or 'gidnumber' in options:
            (dn, old_entry_attrs) = ldap.get_entry(dn, ['objectclass'])
            if 'posixgroup' in old_entry_attrs['objectclass']:
                if options['posix']:
                    raise errors.AlreadyPosixGroup()
            else:
                old_entry_attrs['objectclass'].append('posixgroup')
                entry_attrs['objectclass'] = old_entry_attrs['objectclass']
                if not 'gidnumber' in options:
                    entry_attrs['gidnumber'] = 999
        return dn

api.register(group_mod)


class group_find(LDAPSearch):
    """
    Search for groups.
    """

    msg_summary = ngettext(
        '%(count)d group matched', '%(count)d groups matched', 0
    )

api.register(group_find)


class group_show(LDAPRetrieve):
    """
    Display group.
    """

api.register(group_show)


class group_add_member(LDAPAddMember):
    """
    Add members to group.
    """

api.register(group_add_member)


class group_remove_member(LDAPRemoveMember):
    """
    Remove members from group.
    """

api.register(group_remove_member)


class group_detach(LDAPRemoveMember):
    """
    Detach a managed group from a user
    """
    has_output = output.standard_value
    msg_summary = _('Detached group "%(value)s" from user "%(value)s"')

    def execute(self, *keys, **options):
        """
        This requires updating both the user and the group. We first need to
        verify that both the user and group can be updated, then we go
        about our work. We don't want a situation where only the user or
        group can be modified and we're left in a bad state.
        """
        ldap = self.obj.backend

        group_dn = self.obj.get_dn(*keys, **options)
        user_dn = self.api.Object['user'].get_dn(*keys)

        if (not ldap.can_write(user_dn, "objectclass") or
            not ldap.can_write(user_dn, "mepManagedEntry")):
            raise errors.ACIError(info=_('not allowed to modify user entries'))

        if (not ldap.can_write(group_dn, "objectclass") or
            not ldap.can_write(group_dn, "mepManagedBy")):
            raise errors.ACIError(info=_('not allowed to modify group entries'))

        (user_dn, user_attrs) = ldap.get_entry(user_dn)
        objectclasses = user_attrs['objectclass']
        try:
            i = objectclasses.index('mepOriginEntry')
        except ValueError:
            raise NotFound(reason=_('Not a managed group'))
        del objectclasses[i]
        update_attrs = {'objectclass': objectclasses, 'mepManagedEntry': None}
        ldap.update_entry(user_dn, update_attrs)

        (group_dn, group_attrs) = ldap.get_entry(group_dn)
        objectclasses = group_attrs['objectclass']
        try:
            i = objectclasses.index('mepManagedEntry')
        except ValueError:
            # this should never happen
            raise NotFound(reason=_('Not a managed group'))
        del objectclasses[i]
        update_attrs = {'objectclass': objectclasses, 'mepManagedBy': None}
        ldap.update_entry(group_dn, update_attrs)

        return dict(
            result=True,
            value=keys[0],
        )

api.register(group_detach)