# Copyright 2013: Mirantis Inc.
# All Rights Reserved.
#
#    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 os

import netaddr
import six

from rally.common.i18n import _
from rally.common import log as logging
from rally.common import objects
from rally.common import utils
from rally.deployment import engine
from rally.deployment.serverprovider import provider
from rally.deployment.serverprovider.providers import lxc
from rally import exceptions

LOG = logging.getLogger(__name__)
START_SCRIPT = "start.sh"


def get_script_path(name):
    return os.path.join(os.path.abspath(os.path.dirname(__file__)),
                        "lxc", name)


@engine.configure(name="LxcEngine")
class LxcEngine(engine.Engine):
    """Deploy with other engines in lxc containers.

    Sample configuration:

        {
            "type": "LxcEngine",
            "provider": {
                "type": "DummyProvider",
                "credentials": [{"user": "root", "host": "example.net"}]
            },
            "distribution": "ubuntu",
            "release": "raring",
            "tunnel_to": ["10.10.10.10", "10.10.10.11"],
            "start_lxc_network": "10.1.1.0/24",
            "container_name_prefix": "devstack-node",
            "containers_per_host": 16,
            "start_script": "~/start.sh",
            "engine": { ... }
        }
    """

    CONFIG_SCHEMA = {
        "type": "object",
        "properties": {
            "type": {"type": "string"},
            "distribution": {"type": "string"},
            "release": {"type": "string"},
            "start_lxc_network": {"type": "string",
                                  "pattern": "^(\d+\.){3}\d+\/\d+$"},
            "containers_per_host": {"type": "integer"},
            "tunnel_to": {"type": "array",
                          "elements": {"type": "string",
                                       "pattern": "^(\d+\.){3}\d+$"}},
            "container_name": {"type": "string"},
            "provider": {"type": "object",
                         "properties": {"type": {"type": "string"}}},
        },
        "required": ["type", "containers_per_host", "container_name",
                     "provider"]
    }

    def validate(self):
        super(LxcEngine, self).validate()
        if "start_lxc_network" not in self.config:
            return
        lxc_net = netaddr.IPNetwork(self.config["start_lxc_network"])
        num_containers = self.config["containers_per_host"]
        if lxc_net.size - 3 < num_containers:
            message = _("Network size is not enough for %d hosts.")
            raise exceptions.InvalidConfigException(message % num_containers)

    def _deploy_first(self, lxc_host, name, distribution, release):
        lxc_host.prepare()
        lxc_host.create_container(name, distribution, release)
        lxc_host.start_containers()
        items = six.iteritems(
            lxc_host.get_server_object(name).get_credentials())
        # filter out all keys where value is None
        credentials = dict(filter(lambda x: x[1] is not None, items))
        engine_config = self.config["engine"].copy()
        engine_config["provider"] = {"type": "DummyProvider",
                                     "credentials": [credentials]}
        deployment = objects.Deployment(config=engine_config,
                                        parent_uuid=self.deployment["uuid"])
        deployer = engine.Engine.get_engine(engine_config["name"],
                                            deployment)
        deployer.deploy()
        lxc_host.stop_containers()

    def _get_provider(self):
        return provider.ProviderFactory.get_provider(self.config["provider"],
                                                     self.deployment)

    @utils.log_deploy_wrapper(LOG.info, _("Create containers on host"))
    def deploy(self):
        name = self.config["container_name"]
        start_script = self.config.get("start_script",
                                       get_script_path(START_SCRIPT))
        distribution = self.config["distribution"]
        release = self.config.get("release", None)
        network = self.config.get("start_lxc_network")
        if network:
            network = netaddr.IPNetwork(network)
        else:
            ip = "0"

        self.provider = self._get_provider()

        for server in self.provider.create_servers():
            config = {"tunnel_to": self.config.get("tunnel_to", [])}
            if network:
                config["network"] = str(network)
                ip = str(network.ip).replace(".", "-")
            else:
                ip = "0"
            name_prefix = "%s-%s" % (name, ip)
            first_name = name_prefix + "-000"
            lxc_host = lxc.LxcHost(server, config)
            self._deploy_first(lxc_host, first_name, distribution, release)
            for i in range(1, self.config["containers_per_host"]):
                clone_name = "%s-%03d" % (name_prefix, i)
                lxc_host.create_clone(clone_name, first_name)
            lxc_host.start_containers()
            info = {"host": server.get_credentials(),
                    "containers": lxc_host.containers,
                    "forwarded_ports": lxc_host._port_cache.items(),
                    "config": config}
            self.deployment.add_resource(provider_name="LxcEngine", info=info)
            for container in lxc_host.get_server_objects():
                container.ssh.run("/bin/sh -e", stdin=open(start_script, "rb"))
            if network:
                network += 1
        return {"admin": objects.Endpoint("", "", "", "")}

    def cleanup(self):
        resources = self.deployment.get_resources()
        for resource in resources:
            server = provider.Server.from_credentials(resource.info["host"])
            lxc_host = lxc.LxcHost(server, resource.info["config"])
            lxc_host.containers = resource.info["containers"]
            lxc_host.destroy_containers()
            lxc_host.destroy_ports(resource.info["forwarded_ports"])
            lxc_host.delete_tunnels()
            self.deployment.delete_resource(resource.id)
        self._get_provider().destroy_servers()
