# Copyright 2019 Canonical Ltd
#
# 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.

from charms import reactive
import charmhelpers.contrib.network.ip as ch_net_ip


class MySQLRouterProvides(reactive.Endpoint):

    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.ingress_address = ch_net_ip.get_relation_ip(self.endpoint_name)

    def relation_ids(self):
        return [x.relation_id for x in self.relations]

    def set_ingress_address(self):
        for relation in self.relations:
            relation.to_publish_raw["ingress-address"] = self.ingress_address
            relation.to_publish_raw["private-address"] = self.ingress_address

    def available(self):
        for unit in self.all_joined_units:
            # Check for prefixed username
            for key in unit.received.keys():
                if "_username" in key:
                    return True
        return False

    def set_or_clear_available(self):
        if self.available():
            reactive.set_flag(self.expand_name('{endpoint_name}.available'))
        else:
            reactive.clear_flag(self.expand_name('{endpoint_name}.available'))

    @reactive.when('endpoint.{endpoint_name}.joined')
    def joined(self):
        reactive.set_flag(self.expand_name('{endpoint_name}.connected'))
        self.set_ingress_address()
        self.set_or_clear_available()

    @reactive.when('endpoint.{endpoint_name}.changed')
    def changed(self):
        flags = (
            self.expand_name(
                'endpoint.{endpoint_name}.changed.database'),
            self.expand_name(
                'endpoint.{endpoint_name}.changed.username'),
            self.expand_name(
                'endpoint.{endpoint_name}.changed.hostname'),
        )
        if reactive.all_flags_set(*flags):
            for flag in flags:
                reactive.clear_flag(flag)

        self.set_or_clear_available()

    def remove(self):
        flags = (
            self.expand_name('{endpoint_name}.connected'),
            self.expand_name('{endpoint_name}.available'),
        )
        for flag in flags:
            reactive.clear_flag(flag)

    @reactive.when('endpoint.{endpoint_name}.broken')
    def broken(self):
        self.remove()

    @reactive.when('endpoint.{endpoint_name}.departed')
    def departed(self):
        self.remove()

    def set_db_connection_info(
            self, relation_id, db_host, password,
            allowed_units=None, prefix=None, wait_timeout=None,
            ssl_ca=None):
        """Send database connection information to the client.

        :param relation_id: Relation ID to set connection information on
        :type relation_id: str
        :param db_host: Host IP or hostname for connecting to the DB
        :type db_host: str
        :param wait_timeout: Non-interactive wait timeout in seconds
        :type wait_timeout: int
        :param password: Password for connecting to the DB
        :type password: str
        :param allowed_units: Space delimited unit names allowed to connect to
                              the DB.
        :type allowed_units: str
        :param prefix: Prefix to use for responses.
        :type prefix: str
        :side effect: Data is set on the relation
        :returns: None, this function is called for its side effect
        :rtype: None
        """
        self._set_db_connection_info(
            getattr(self.relations[relation_id], 'to_publish_app'),
            db_host, password, allowed_units, prefix, wait_timeout, ssl_ca)
        # NOTE(ganso): Deprecated non-app-bag data for backwards compatibility
        self._set_db_connection_info(
            getattr(self.relations[relation_id], 'to_publish'),
            db_host, password, allowed_units, prefix, wait_timeout, ssl_ca)

    def _set_db_connection_info(
            self, publish_prop, db_host, password,
            allowed_units=None, prefix=None, wait_timeout=None,
            ssl_ca=None):
        # No prefix for db_host or wait_timeout
        publish_prop["db_host"] = db_host
        if wait_timeout:
            publish_prop["wait_timeout"] = wait_timeout
        if ssl_ca:
            publish_prop["ssl_ca"] = ssl_ca
        if not prefix:
            publish_prop["password"] = password
            publish_prop["allowed_units"] = allowed_units
        else:
            publish_prop["{}_password".format(prefix)] = password
            publish_prop["{}_allowed_units".format(prefix)] = allowed_units