import json
import logging
import socket
import time

from django.utils import timezone
import networkx as nx

from backend import gobgp, cmk_parser
from backend.exceptions import RouterParserException
from bgpdata.models import ConfigHost, ASLastSeen, ASLastSeenNeighbor, CrawlRun

log = logging.getLogger(__name__)
FORMAT = '%(asctime)-15s %(message)s'
logging.basicConfig(level=logging.INFO, format=FORMAT)
log.setLevel(logging.INFO)


def crawl():
    net = get_current_network()
    crawl = make_crawl_from_net(net)
    crawl.save()

    # handle last seen ASNs
    log.info("Updating last seen info")
    last_seen = {}
    for asls in ASLastSeen.objects.all():
        last_seen[asls.asn] = asls

    for asn, node in net.nodes(data=True):
        if asn not in last_seen:
            last_seen[asn] = ASLastSeen(asn=asn)
        asls = last_seen[asn]
        asls.online = node['online']
        if node['online']:
            asls.directlyCrawled = node['directly_crawled']
            asls.lastSeen = timezone.now()
            asls.crawlLastSeen = crawl
        else:
            asls.directlyCrawled = False
        asls.save()

        if asls.online:
            neighs = net.neighbors(asn)
            db_neighs = set()
            for db_neigh in asls.aslastseenneighbor_set.all():
                if db_neigh.asn in neighs:
                    db_neighs.add(asls.asn)
                else:
                    db_neigh.delete()
            for neigh in neighs:
                if neigh not in db_neighs:
                    asneigh = ASLastSeenNeighbor(asn=neigh, neighbor=asls)
                    asneigh.save()
                    db_neighs.add(neigh)

    crawl.endTime = timezone.now()
    crawl.save()

    log.info("Automated crawl done")


def make_crawl_from_net(net):
    """Create a CrawlRun, but don't save it"""
    asCount = asOnlineCount = asOfflineCount = 0
    for asn, node in net.nodes(data=True):
        asCount += 1
        if node['online']:
            asOnlineCount += 1
        else:
            asOfflineCount += 1

    crawl = CrawlRun()
    crawl.startTime = timezone.now()
    crawl.graph = net_to_json(net)
    crawl.asCount = asCount
    crawl.asOnlineCount = asOnlineCount
    crawl.asOfflineCount = asOfflineCount
    crawl.peeringCount = len(net.edges)

    return crawl


def get_current_network():
    net = nx.Graph()

    crawl_start = time.time()
    log.info("Crawl run started")
    for host in ConfigHost.objects.all():
        try:
            if host.checkMethod == 'CMK':
                data = cmk_parser.getBGPData(host.ip, host.number)
                _add_data_to_net(net, data)
            elif host.checkMethod == 'GOBGP':
                for entry in gobgp.get_bgp_data(host.ip):
                    _add_data_to_net(net, entry)
        except (RouterParserException, socket.error):
            log.exception("Could not get data from host %s method %s", host, host.checkMethod)
            continue

    log.info("Adding last seen neighbor info")
    for asls in ASLastSeen.objects.all():
        if asls.asn not in net.nodes:
            if any(neigh.asn in net.nodes for neigh in asls.aslastseenneighbor_set.all()):
                _populate_node(net, asls.asn)
                net.nodes[asls.asn]['online'] = False
                for neigh in asls.aslastseenneighbor_set.all():
                    if neigh.asn not in net.nodes:
                        _populate_node(net, neigh.asn)
                        net.nodes[asls.asn]['online'] = False

    # add neighbor count
    for node, data in net.nodes(data=True):
        data["neighbors"] = len(list(net.neighbors(node)))

    log.info("Crawl done in %.2fs", time.time() - crawl_start)

    # add id to edges
    for n, (_, _, data) in enumerate(net.edges(data=True)):
        data['id'] = n

    # import IPython
    # IPython.embed()

    return net


def net_to_json(net):
    """Dum net to json, will replace all sets from the graph"""
    # replace all sets with lists for better dumpability
    for node in net.nodes.values():
        for key, val in node.items():
            if isinstance(val, set):
                node[key] = list(val)

    return json.dumps(nx.readwrite.json_graph.node_link_data(net))


def _populate_node(net, asn):
    net.add_node(asn)
    node = net.nodes[asn]
    node.setdefault("prefixes", set())
    node.setdefault("router_ids", set())
    node.setdefault("routing_table", set())
    node.setdefault("directly_crawled", False)
    node.setdefault("online", True)
    node.setdefault("stub", True)
    return node


def _add_data_to_net(net, data):
    asn = data['local_as']
    as_node = _populate_node(net, asn)
    as_node['router_ids'].add(data['local_id'])
    as_node['directly_crawled'] = True

    for peer in data['peers']:
        pass

    for route in data['routes']:
        as_node['routing_table'].add((route['prefix'], tuple(route['path'])))

        as_path = route['path']
        if not as_path:
            continue

        orig_node = _populate_node(net, as_path[-1])
        orig_node['prefixes'].add(route['prefix'])

        for n in range(len(as_path) - 1):
            if as_path[n] != as_path[n + 1]:
                if as_path[n + 1] not in net.nodes:
                    _populate_node(net, as_path[n + 1])
                if as_path[n + 1] not in (as_path[-1], as_path[0]):
                    net.nodes[as_path[n + 1]]['stub'] = False
                net.add_edge(as_path[n], as_path[n + 1])


def convert_crawl(crawl):
    net = nx.Graph()

    for asn in crawl.as_set.all():
        if asn.number not in net.nodes:
            _populate_node(net, asn.number)
            d = net.nodes[asn.number]
            d['online'] = asn.online
            d['directly_crawled'] = asn.directlyCrawled
            for br in asn.borderrouter_set.all():
                d['router_ids'].add(br.routerID)

    for asn in crawl.as_set.all():
        for peering in asn.getPeerings():
            net.add_edge(peering.as1.number, peering.as2.number)

        for ann in asn.announcement_set.all():
            prefix = "{}/{}".format(ann.ip, ann.prefix)
            path = list(map(int, ann.ASPath.split()))
            net.nodes[asn.number]['routing_table'].add((prefix, tuple(path)))
            if path:
                net.nodes[path[-1]]['prefixes'].add(prefix)
                for path_asn in path:
                    if path_asn not in (path[-1], path[0]):
                        net.nodes[path_asn]['stub'] = False

    # add neighbor count
    for node, data in net.nodes(data=True):
        data["neighbors"] = len(list(net.neighbors(node)))

    return net