# -*- coding: utf-8 -*-
#
# Copyright (C) 2007, 2008, 2009 by Jan Dittberner.
#
# 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 Street, Fifth Floor, Boston, MA 02110-1301,
# USA.
#
# Version: $Id$

from sqlalchemy import MetaData, Table
from sqlalchemy.orm import mapper, relation
from sqlalchemy.exceptions import NoSuchTableError
import sys
import migrate.versioning.api
import logging
from gnuviechadmin.backend.BackendTo import Client, Sysuser, Domain, Record


def dbsetup(config):
    logger = logging.getLogger(__name__)
    required_version = int(config['migrate.required_version'])
    try:
        dbversion = migrate.versioning.api.db_version(
            config['sqlalchemy.uri'], config['database.repository'])
        if dbversion < required_version:
            logger.info("""Database version is %d but required version \
is %d. Trying automatic upgrade.""" % (dbversion, required_version))
            try:
                migrate.versioning.api.upgrade(
                    config['sqlalchemy.uri'], config['database.repository'],
                    required_version)
            except e:
                logger.error("Automatic upgrade failed.", e)
                raise
        elif dbversion > required_version:
            logger.error("""Database version is %d which is higher than \
the required version %d. I cannot handle this situation without possible \
data loss.""" % (dbversion, required_version))
            sys.exit(1)
    except NoSuchTableError, nste:
        logger.info("""The database is not versioned. \
Trying automatic versioning.""")
        try:
            migrate.versioning.api.version_control(
                config['sqlalchemy.uri'], config['database.repository'])
            migrate.versioning.api.upgrade(
                config['sqlalchemy.uri'], config['database.repository'],
                required_version)
        except:
            logger.error("Automatic setup failed.")
            raise

    meta = MetaData(config['sqlalchemy.uri'])
    meta.bind.engine.echo = config['sqlalchemy.echo']

    dbschema = None
    if 'database.schema' in config:
        dbschema = config['database.schema']
    
    (client_table, sysuser_table, domain_table, \
         record_table, supermaster_table, mailaccount_table, \
         mailaddress_table, mailtarget_table) = \
         [Table(tabname, meta, schema = dbschema,
                autoload = True) for tabname in \
              ('client', 'sysuser', 'domain', 'record',
               'supermaster', 'mailaccount', 'mailaddress', 'mailtarget')]

    client_mapper = mapper(Client, client_table, {
            'sysusers': relation(Sysuser, backref = 'client')})
    sysuser_mapper = mapper(Sysuser, sysuser_table, {
            'domains': relation(Domain, backref = 'sysuser')})
    domain_mapper = mapper(Domain, domain_table, {
            'records': relation(Record, cascade = 'all',
                                backref = 'domain')})
    record_mapper = mapper(Record, record_table)