# Copyright 2015 Rackspace Australia
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.

import logging
import re
from collections import OrderedDict

import zuul.driver.zuul
import zuul.driver.gerrit
import zuul.driver.git
import zuul.driver.github
import zuul.driver.smtp
import zuul.driver.timer
import zuul.driver.sql
import zuul.driver.bubblewrap
import zuul.driver.nullwrap
from zuul.connection import BaseConnection
from zuul.driver import SourceInterface


class DefaultConnection(BaseConnection):
    pass


class ConnectionRegistry(object):
    """A registry of connections"""

    log = logging.getLogger("zuul.ConnectionRegistry")

    def __init__(self):
        self.connections = OrderedDict()
        self.drivers = {}

        self.registerDriver(zuul.driver.zuul.ZuulDriver())
        self.registerDriver(zuul.driver.gerrit.GerritDriver())
        self.registerDriver(zuul.driver.git.GitDriver())
        self.registerDriver(zuul.driver.github.GithubDriver())
        self.registerDriver(zuul.driver.smtp.SMTPDriver())
        self.registerDriver(zuul.driver.timer.TimerDriver())
        self.registerDriver(zuul.driver.sql.SQLDriver())
        self.registerDriver(zuul.driver.bubblewrap.BubblewrapDriver())
        self.registerDriver(zuul.driver.nullwrap.NullwrapDriver())

    def registerDriver(self, driver):
        if driver.name in self.drivers:
            raise Exception("Driver %s already registered" % driver.name)
        self.drivers[driver.name] = driver

    def registerScheduler(self, sched, load=True):
        for driver_name, driver in self.drivers.items():
            if hasattr(driver, 'registerScheduler'):
                driver.registerScheduler(sched)
        for connection_name, connection in self.connections.items():
            connection.registerScheduler(sched)
            if load:
                connection.onLoad()

    def reconfigureDrivers(self, tenant):
        for driver in self.drivers.values():
            if hasattr(driver, 'reconfigure'):
                driver.reconfigure(tenant)

    def stop(self):
        for connection_name, connection in self.connections.items():
            connection.onStop()
        for driver in self.drivers.values():
            driver.stop()

    def configure(self, config, source_only=False):
        # Register connections from the config
        connections = OrderedDict()

        for section_name in config.sections():
            con_match = re.match(r'^connection ([\'\"]?)(.*)(\1)$',
                                 section_name, re.I)
            if not con_match:
                continue
            con_name = con_match.group(2)
            con_config = dict(config.items(section_name))

            if 'driver' not in con_config:
                raise Exception("No driver specified for connection %s."
                                % con_name)

            con_driver = con_config['driver']
            if con_driver not in self.drivers:
                raise Exception("Unknown driver, %s, for connection %s"
                                % (con_config['driver'], con_name))

            driver = self.drivers[con_driver]

            # The merger and the reporter only needs source driver.
            # This makes sure Reporter like the SQLDriver are only created by
            # the scheduler process
            if source_only and not isinstance(driver, SourceInterface):
                continue

            connection = driver.getConnection(con_name, con_config)
            connections[con_name] = connection

        # If the [gerrit] or [smtp] sections still exist, load them in as a
        # connection named 'gerrit' or 'smtp' respectfully

        if 'gerrit' in config.sections():
            if 'gerrit' in connections:
                self.log.warning(
                    "The legacy [gerrit] section will be ignored in favour"
                    " of the [connection gerrit].")
            else:
                driver = self.drivers['gerrit']
                connections['gerrit'] = \
                    driver.getConnection(
                        'gerrit', dict(config.items('gerrit')))

        if 'smtp' in config.sections():
            if 'smtp' in connections:
                self.log.warning(
                    "The legacy [smtp] section will be ignored in favour"
                    " of the [connection smtp].")
            else:
                driver = self.drivers['smtp']
                connections['smtp'] = \
                    driver.getConnection(
                        'smtp', dict(config.items('smtp')))

        # Create default connections for drivers which need no
        # connection information (e.g., 'timer' or 'zuul').
        if not source_only:
            for driver in self.drivers.values():
                if not hasattr(driver, 'getConnection'):
                    connections[driver.name] = DefaultConnection(
                        driver, driver.name, {})

        self.connections = connections

    def getSource(self, connection_name):
        connection = self.connections[connection_name]
        return connection.driver.getSource(connection)

    def getSources(self):
        sources = []
        for connection in self.connections.values():
            if hasattr(connection.driver, 'getSource'):
                sources.append(connection.driver.getSource(connection))
        return sources

    def getReporter(self, connection_name, config=None):
        connection = self.connections[connection_name]
        return connection.driver.getReporter(connection, config)

    def getTrigger(self, connection_name, config=None):
        connection = self.connections[connection_name]
        return connection.driver.getTrigger(connection, config)

    def getSourceByHostname(self, hostname):
        for connection in self.connections.values():
            if hasattr(connection, 'canonical_hostname'):
                if connection.canonical_hostname == hostname:
                    return self.getSource(connection.connection_name)
            if hasattr(connection, 'server'):
                if connection.server == hostname:
                    return self.getSource(connection.connection_name)
        return None

    def getSourceByCanonicalHostname(self, canonical_hostname):
        for connection in self.connections.values():
            if hasattr(connection, 'canonical_hostname'):
                if connection.canonical_hostname == canonical_hostname:
                    return self.getSource(connection.connection_name)
        return None