import logging
import os
# Facility to determine GPTs for user
from samba.gpclass import check_safe_path, check_refresh_gpo_list

from .applier_backend import applier_backend
from storage import cache_factory, registry_factory
from gpt import gpt, get_local_gpt
import util
import util.preg

class samba_backend(applier_backend):
    __default_policy_path = '/usr/share/local-policy/default'

    def __init__(self, sambacreds, username, domain):
        self.storage = registry_factory('registry')
        self.storage.set_info('domain', domain)
        self.storage.set_info('machine_name', util.get_machine_name())
        self.storage.set_info('machine_sid', util.get_sid(domain, self.storage.get_info('machine_name')))

        # User SID to work with HKCU hive
        self.username = username
        self._is_machine_username = util.is_machine_name(self.username)
        self.sid = util.get_sid(self.storage.get_info('domain'), self.username)

        self.cache = cache_factory('regpol_cache')
        self.gpo_names = cache_factory('gpo_names')

        # Samba objects - LoadParm() and CredentialsOptions()
        self.sambacreds = sambacreds

        self.cache_dir = self.sambacreds.get_cache_dir()
        logging.debug('Cache directory is: {}'.format(self.cache_dir))

    def retrieve_and_store(self):
        '''
        Retrieve settings and strore it in a database
        '''
        # Get policies for machine at first.
        machine_gpts = self._get_gpts(util.get_machine_name(), self.storage.get_info('machine_sid'))
        self.storage.wipe_hklm()
        self.storage.wipe_user(self.storage.get_info('machine_sid'))
        for gptobj in machine_gpts:
            gptobj.merge()

        # Load user GPT values in case user's name specified
        # This is a buggy implementation and should be tested more
        if not self._is_machine_username:
            user_gpts = self._get_gpts(self.username, self.sid)
            self.storage.wipe_user(self.sid)
            for gptobj in user_gpts:
                gptobj.merge()

    def _check_sysvol_present(self, gpo):
        '''
        Check if there is SYSVOL path for GPO assigned
        '''
        if not gpo.file_sys_path:
            # GPO named "Local Policy" has no entry by its nature so
            # no reason to print warning.
            if 'Local Policy' != gpo.name:
                logging.warning('No SYSVOL entry assigned to GPO {}'.format(gpo.name))
            return False
        return True

    def _get_gpts(self, username, sid):
        gpts = list()

        gpos = self.sambacreds.update_gpos(username)
        for gpo in gpos:
            if self._check_sysvol_present(gpo):
                logging.debug('Found SYSVOL entry "{}" for GPO "{}"'.format(gpo.file_sys_path, gpo.display_name))
                path = check_safe_path(gpo.file_sys_path).upper()
                logging.debug('Path: {}'.format(path))
                gpt_abspath = os.path.join(self.cache_dir, 'gpo_cache', path)
                obj = gpt(gpt_abspath, sid)
                obj.set_name(gpo.display_name)
                gpts.append(obj)
            else:
                if 'Local Policy' == gpo.name:
                    gpts.append(get_local_gpt(sid))

        logging.debug('GPTs found:')
        for gptobj in gpts:
            logging.debug(gptobj)
        logging.debug('---')

        return gpts