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

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

from django.utils import timezone
from django.db.models import Q

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


def getOrCreateAS(crawl, number):
	currAS = None
	try:
		currAS = AS.objects.get(crawl=crawl, number=number)
	except AS.DoesNotExist:
		currAS = AS(crawl=crawl, number=number)
		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():
		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)

		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 = None
			try:
				neighAS = AS.objects.get(crawl=crawl, number=int(peer["BGP"]["neighbor_as"]))
			except AS.DoesNotExist:
				neighAS = AS(crawl=crawl, number=int(peer["BGP"]["neighbor_as"]))
				neighAS.save()

			# 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=currAS, 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
				ip, prefix = route["prefix"].split("/")
				a = Announcement(router=currRouter, ip=ip, prefix=prefix,
									ASPath=" ".join(route["path"]), nextHop=route["nexthop"],
									originAS=currAS)
				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

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

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

if __name__ == '__main__':
	main()