#!/usr/bin/env python2
from __future__ import print_function

# config
LAST_SEEN_DAYS = 7

# prepare environment
import sys
sys.path.append("..")
import os
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "dnmapper.settings")
import django
django.setup()

import datetime
from django.utils import timezone
from django.db.models import Q, Max

from bgpdata.models import ConfigHost, CrawlRun, CrawlLog, AS, BorderRouter, Announcement, Peering, BorderRouterPair
from routerparsers import getBGPData, RouterParserException


def getOrCreateAS(crawl, number, online=True):
	currAS = None
	try:
		currAS = AS.objects.get(crawl=crawl, number=number)
		if online:
			currAS.setOnline()
	except AS.DoesNotExist:
		currAS = AS(crawl=crawl, number=number, online=online)
		currAS.save()

	return currAS

def main():
	# 1. create crawl run
	crawl = CrawlRun()
	crawl.startTime = timezone.now()
	crawl.save()

	CrawlLog.log(crawl, "Starting crawl run!", severity=CrawlLog.INFO)

	# 2. get data from all hosts, put it in the database
	for host in ConfigHost.objects.all():
		crawl.hostsCrawled.add(host)
		data = None
		print(" -- Getting data for host %s" % host)
		try:
			if host.checkMethod == 'CMK':
				data = getBGPData(host.ip, host.number)
			else:
				CrawlLog.log(crawl, "Method %s is not currently supported, skipping host" % host.checkMethod, host=host, severity=CrawlLog.ERROR)
				continue
		except RouterParserException as e:
			msg = "Could not parse data for host: %s" % str(e)
			print("%s: %s" % (host, msg))
			CrawlLog.log(crawl, msg, host=host, severity=CrawlLog.ERROR)
			continue

		print(" -- parsing...")

		currASno = int(data["local_as"])
		currAS = getOrCreateAS(crawl, currASno)

		currAS.directlyCrawled = True
		currAS.save()

		currRouter = None
		try:
			currRouter = BorderRouter.objects.get(AS=currAS, routerID=data["local_id"])
			currRouter.pingable = True
			currRouter.reachable = True
			currRouter.save()
		except BorderRouter.DoesNotExist:
			currRouter = BorderRouter(AS=currAS, routerID=data["local_id"], pingable=True, reachable=True)
			currRouter.save()

		print(" --> peers")
		for peer in data["peers"]:
			# peerings
			# data: BGP{state, neighbor_id, neighbor_as}, description

			# a) find/create neighbor
			print(" ----> Peer:", int(peer["BGP"]["neighbor_as"]))
			neighAS = getOrCreateAS(crawl, int(peer["BGP"]["neighbor_as"]), online=peer["BGP"]["online"])

			# b) find out if a peering already exists (maybe where we only need to add our router id?)
			peering = None
			try:
				peering = Peering.getPeering(currAS, neighAS)
			except Peering.DoesNotExist:
				peering = Peering(as1=currAS, as2=neighAS, origin=Peering.DIRECT)
				peering.save()

			# c) look for router/peering pairs
			if peer["BGP"]["neighbor_id"]:
				try:
					neighRouter = BorderRouter.objects.get(AS=neighAS, routerID=peer["BGP"]["neighbor_id"])
				except BorderRouter.DoesNotExist:
					neighRouter = BorderRouter(AS=neighAS, routerID=peer["BGP"]["neighbor_id"], pingable=False, reachable=False)
					neighRouter.save()
				try:
					BorderRouterPair.getPairing(peering, currRouter, neighRouter)
				except BorderRouterPair.DoesNotExist:
					pairs = BorderRouterPair.objects.filter(Q(peering=peering) & (Q(router1=neighRouter, router2=None)|Q(router1=None, router2=neighRouter)))
					if pairs.count() > 0:
						pair = pairs[0]
						if pair.router1 == None:
							pair.router1 = currRouter
						else:
							pair.router2 = currRouter
						pair.save()
					else:
						pair = BorderRouterPair(peering=peering, router1=currRouter, router2=neighRouter)
						pair.save()

		print(" --> Announcements")
		if "routes" in data and data["routes"]:
			for route in data["routes"]:
				print(" ---->", route["prefix"])
				if "/" not in route["prefix"]:
					continue

				originAS = currAS
				if len(route["path"]) > 0:
					originAS = getOrCreateAS(crawl, route["path"][0])
				ip, prefix = route["prefix"].split("/")
				a = Announcement(router=currRouter, ip=ip, prefix=prefix,
									ASPath=" ".join(route["path"]), nextHop=route["nexthop"],
									originAS=originAS)
				a.save()
		else:
			print(" !! No routes found in host output")
			CrawlLog.log(crawl, "No routes found in host output (no bgp feed included?)", host=host, severity=CrawlLog.WARN)

	# 3. calculate missing data
	print(" -- Adding extra data from announcements...")
	# 3.1. use announcement data to find hidden peerings
	for announcement in Announcement.objects.filter(router__AS__crawl=crawl):
		path = announcement.ASPath.split(" ")
		if len(path) > 1:
			firstASno = path.pop(0)
			firstAS = getOrCreateAS(crawl, firstASno)
			while len(path) > 0:
				secondASno = path.pop(0)
				secondAS = getOrCreateAS(crawl, secondASno)

				try:
					Peering.getPeering(firstAS, secondAS)
				except Peering.DoesNotExist:
					peering = Peering(as1=firstAS, as2=secondAS, origin=Peering.PATH)
					peering.save()

				firstAS = secondAS

	# 3.2 add ASses, routers and peerings from old crawlruns (last should suffice)
	# find 
	print(" --> copy old ASses")
	timerangeStart = crawl.startTime - datetime.timedelta(LAST_SEEN_DAYS)
	oldASses = AS.objects.filter(online=True, crawl__startTime__gte=timerangeStart).values("number").annotate(lastSeen=Max('crawl_id')).filter(~Q(lastSeen=crawl.pk))

	# 3.2.1. copy old asses
	print(" ----> create ASses")
	for oldASdata in oldASses:
		print(" ------> AS", oldASdata["number"])
		oldAS = AS.objects.get(number=oldASdata["number"], crawl=oldASdata["lastSeen"])

		try:
			newAS = AS.objects.get(number=oldAS.number, crawl=crawl)
			if not newAS.online and not newAS.lastSeen:
				newAS.lastSeen = oldAS.crawl
				newAS.save()
		except:
			newAS = AS(number=oldAS.number, crawl=crawl, lastSeen=oldAS.crawl, directlyCrawled=False, online=False)
			newAS.save()

	# 3.2.2 copy peerings between old asses
	print(" ----> copy peerings")
	for oldASdata in oldASses:
		print(" ------> AS", oldASdata["number"])
		oldAS = AS.objects.get(number=oldASdata["number"], crawl=oldASdata["lastSeen"])
		for peering in oldAS.getPeerings():
			print(" --------> Peering %s <--> %s" % (peering.as1.number, peering.as2.number))
			peering = Peering(
						as1=AS.objects.get(number=peering.as1.number, crawl=crawl), 
						as2=AS.objects.get(number=peering.as2.number, crawl=crawl),
						origin=peering.origin)
			peering.save()

	# 3.3 FIXME: do we also want to have old peerings which do not exist anymore?

	# 4. end crawl run
	crawl.endTime = timezone.now()
	crawl.save()

	print(" !! Done")
	CrawlLog.log(crawl, "Crawl completed", severity=CrawlLog.INFO)

if __name__ == '__main__':
	main()