"""
Copyright (c) 2015 SONATA-NFV and Paderborn University
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.

Neither the name of the SONATA-NFV [, ANY ADDITIONAL AFFILIATION]
nor the names of its contributors may be used to endorse or promote
products derived from this software without specific prior written
permission.

This work has been performed in the framework of the SONATA project,
funded by the European Commission under Grant number 671517 through
the Horizon 2020 and 5G-PPP programmes. The authors would like to
acknowledge the contributions of their colleagues of the SONATA
partner consortium (www.sonata-nfv.eu).
"""
from mininet.node import Docker
from mininet.link import Link
from emuvim.dcemulator.resourcemodel import NotEnoughResourcesAvailable
import logging
import time
import json

LOG = logging.getLogger("dcemulator.node")
LOG.setLevel(logging.DEBUG)


DCDPID_BASE = 1000  # start of switch dpid's used for data center switches

class EmulatorCompute(Docker):
    """
    Emulator specific compute node class.
    Inherits from Containernet's Docker host class.
    Represents a single container connected to a (logical)
    data center.
    We can add emulator specific helper functions to it.
    """

    def __init__(
            self, name, dimage, **kwargs):
        self.datacenter = kwargs.get("datacenter")  # pointer to current DC
        self.flavor_name = kwargs.get("flavor_name")
        LOG.debug("Starting compute instance %r in data center %r" % (name, str(self.datacenter)))
        # call original Docker.__init__
        Docker.__init__(self, name, dimage, **kwargs)

    def getNetworkStatus(self):
        """
        Helper method to receive information about the virtual networks
        this compute instance is connected to.
        """
        # get all links and find dc switch interface
        networkStatusList = []
        for i in self.intfList():
            vnf_name = self.name
            vnf_interface = str(i)
            dc_port_name = self.datacenter.net.find_connected_dc_interface(vnf_name, vnf_interface)
            # format list of tuples (name, Ip, MAC, isUp, status, dc_portname)
            intf_dict = {'intf_name': str(i), 'ip': i.IP(), 'mac': i.MAC(), 'up': i.isUp(), 'status': i.status(), 'dc_portname': dc_port_name}
            networkStatusList.append(intf_dict)

        return networkStatusList

    def getStatus(self):
        """
        Helper method to receive information about this compute instance.
        """
        status = {}
        status["name"] = self.name
        status["network"] = self.getNetworkStatus()
        status["docker_network"] = self.dcinfo['NetworkSettings']['IPAddress']
        status["image"] = self.dimage
        status["flavor_name"] = self.flavor_name
        status["cpu_quota"] = self.resources.get('cpu_quota')
        status["cpu_period"] = self.resources.get('cpu_period')
        status["cpu_shares"] = self.resources.get('cpu_shares')
        status["cpuset"] = self.resources.get('cpuset_cpus')
        status["mem_limit"] = self.resources.get('mem_limit')
        status["memswap_limit"] = self.resources.get('memswap_limit')
        status["state"] = self.dcli.inspect_container(self.dc)["State"]
        status["id"] = self.dcli.inspect_container(self.dc)["Id"]
        status["short_id"] = self.dcli.inspect_container(self.dc)["Id"][:12]
        status["datacenter"] = (None if self.datacenter is None
                                else self.datacenter.label)
        return status


class Datacenter(object):
    """
    Represents a logical data center to which compute resources
    (Docker containers) can be added at runtime.

    Will also implement resource bookkeeping in later versions.
    """

    DC_COUNTER = 1

    def __init__(self, label, metadata={}, resource_log_path=None):
        self.net = None  # DCNetwork to which we belong
        # each node (DC) has a short internal name used by Mininet
        # this is caused by Mininets naming limitations for swtiches etc.
        self.name = "dc%d" % Datacenter.DC_COUNTER
        Datacenter.DC_COUNTER += 1
        # use this for user defined names that can be longer than self.name
        self.label = label
        # dict to store arbitrary metadata (e.g. latitude and longitude)
        self.metadata = metadata
        # path to which resource information should be logged (e.g. for experiments). None = no logging
        self.resource_log_path = resource_log_path
        # first prototype assumes one "bigswitch" per DC
        self.switch = None
        # keep track of running containers
        self.containers = {}
        # pointer to assigned resource model
        self._resource_model = None

    def __repr__(self):
        return self.label

    def _get_next_dc_dpid(self):
        global DCDPID_BASE
        DCDPID_BASE += 1
        return DCDPID_BASE

    def create(self):
        """
        Each data center is represented by a single switch to which
        compute resources can be connected at run time.

        TODO: This will be changed in the future to support multiple networks
        per data center
        """
        self.switch = self.net.addSwitch(
            "%s.s1" % self.name, dpid=hex(self._get_next_dc_dpid())[2:])
        LOG.debug("created data center switch: %s" % str(self.switch))

    def start(self):
        pass

    def startCompute(self, name, image=None, command=None, network=None, flavor_name="tiny", **params):
        """
        Create a new container as compute resource and connect it to this
        data center.
        :param name: name (string)
        :param image: image name (string)
        :param command: command (string)
        :param network: networks list({"ip": "10.0.0.254/8"}, {"ip": "11.0.0.254/24"})
        :param flavor_name: name of the flavor for this compute container
        :return:
        """
        assert name is not None
        # no duplications
        if name in [c.name for c in self.net.getAllContainers()]:
            raise Exception("Container with name %s already exists." % name)
        # set default parameter
        if image is None:
            image = "ubuntu:trusty"
        if network is None:
            network = {}  # {"ip": "10.0.0.254/8"}
        if isinstance(network, dict):
            network = [network]  # if we have only one network, put it in a list
        if isinstance(network, list):
            if len(network) < 1:
                network.append({})

        # apply hard-set resource limits=0
        cpu_percentage = params.get('cpu_percent')
        if cpu_percentage:
            params['cpu_period'] = self.net.cpu_period
            params['cpu_quota'] = self.net.cpu_period * float(cpu_percentage)

        # create the container
        d = self.net.addDocker(
            "%s" % (name),
            dimage=image,
            dcmd=command,
            datacenter=self,
            flavor_name=flavor_name,
            environment = {'VNF_NAME':name},
            **params
        )



        # apply resource limits to container if a resource model is defined
        if self._resource_model is not None:
            try:
                self._resource_model.allocate(d)
                self._resource_model.write_allocation_log(d, self.resource_log_path)
            except NotEnoughResourcesAvailable as ex:
                LOG.warning("Allocation of container %r was blocked by resource model." % name)
                LOG.info(ex.message)
                # ensure that we remove the container
                self.net.removeDocker(name)
                return None

        # connect all given networks
        # if no --net option is given, network = [{}], so 1 empty dict in the list
        # this results in 1 default interface with a default ip address
        for nw in network:
            # clean up network configuration (e.g. RTNETLINK does not allow ':' in intf names
            if nw.get("id") is not None:
                nw["id"] = self._clean_ifname(nw["id"])
            # TODO we cannot use TCLink here (see: https://github.com/mpeuster/containernet/issues/3)
            self.net.addLink(d, self.switch, params1=nw, cls=Link, intfName1=nw.get('id'))
        # do bookkeeping
        self.containers[name] = d
        return d  # we might use UUIDs for naming later on

    def stopCompute(self, name):
        """
        Stop and remove a container from this data center.
        """
        assert name is not None
        if name not in self.containers:
            raise Exception("Container with name %s not found." % name)
        LOG.debug("Stopping compute instance %r in data center %r" % (name, str(self)))

        #  stop the monitored metrics
        if self.net.monitor_agent is not None:
            self.net.monitor_agent.stop_metric(name)

        # call resource model and free resources
        if self._resource_model is not None:
            self._resource_model.free(self.containers[name])
            self._resource_model.write_free_log(self.containers[name], self.resource_log_path)

        # remove links
        self.net.removeLink(
            link=None, node1=self.containers[name], node2=self.switch)

        # remove container
        self.net.removeDocker("%s" % (name))
        del self.containers[name]

        return True

    def listCompute(self):
        """
        Return a list of all running containers assigned to this
        data center.
        """
        return list(self.containers.itervalues())

    def getStatus(self):
        """
        Return a dict with status information about this DC.
        """
        return {
            "label": self.label,
            "internalname": self.name,
            "switch": self.switch.name,
            "n_running_containers": len(self.containers),
            "metadata": self.metadata
        }

    def assignResourceModel(self, rm):
        """
        Assign a resource model to this DC.
        :param rm: a BaseResourceModel object
        :return:
        """
        if self._resource_model is not None:
            raise Exception("There is already an resource model assigned to this DC.")
        self._resource_model = rm
        self.net.rm_registrar.register(self, rm)
        LOG.info("Assigned RM: %r to DC: %r" % (rm, self))

    @staticmethod
    def _clean_ifname(name):
        """
        Cleans up given string to be a
        RTNETLINK compatible interface name.
        :param name: string
        :return: string
        """
        if name is None:
            return "if0"
        name = name.replace(":", "-")
        name = name.replace(" ", "-")
        name = name.replace(".", "-")
        name = name.replace("_", "-")
        return name

