from django.db import models
from django.db.models import Q


# Create your models here.
class ConfigHost(models.Model):
	CHECK_CHOICES = (
		('CMK', "Check MK"),
		('PLAIN', "Plain"),
	)

	# asno, ip, check method,
	name = models.CharField(max_length=50)
	number = models.IntegerField()
	ip = models.GenericIPAddressField()
	checkMethod = models.CharField(max_length=4, choices=CHECK_CHOICES)

	def __unicode__(self):
		return u"%s (%s / %s)" % (self.name, self.number, self.ip)

class CrawlRun(models.Model):
	# time start, time end, 
	startTime = models.DateTimeField()
	endTime = models.DateTimeField(null=True, blank=True)

	def __unicode__(self):
		return u"Run %d - %s to %s" % (self.pk, self.startTime, self.endTime if self.endTime else "?")

class CrawlLog(models.Model):
	INFO = 'INFO'
	ERROR = 'ERROR'
	DEBUG = 'DEBUG'
	WARN = 'WARN'
	SEVERITY = (
		(INFO, 'info'),
		(ERROR, 'error'),
		(DEBUG, 'debug'),
		(WARN, 'warning'),
	)

	crawl = models.ForeignKey(CrawlRun)
	host = models.ForeignKey(ConfigHost, null=True, blank=True, on_delete=models.SET_NULL)
	logtime = models.DateTimeField(auto_now_add=True)
	severity = models.CharField(max_length=10, choices=SEVERITY)
	message = models.TextField()

	@staticmethod
	def log(crawl, msg, severity=None, host=None):
		if not severity:
			severity = CrawlLog.ERROR

		log = CrawlLog()
		log.crawl = crawl
		log.message = msg
		log.severity = severity
		log.host = host
		log.save()

	def __unicode__(self):
		host = "host %s - " % self.host.name if self.host else ""
		return u"Log %s %s: %s%s" % (self.get_severity_display(), self.logtime, host, self.message)

class AS(models.Model):
	# asno
	crawl = models.ForeignKey(CrawlRun)
	number = models.IntegerField()

	directlyCrawled = models.BooleanField(default=False)
	online = models.BooleanField(default=True)
	lastSeen = models.ForeignKey(CrawlRun, blank=True, null=True, default=None, related_name='as_lastseen')

	def __unicode__(self):
		return u"AS %s (crawl %d)" % (self.number, self.crawl.pk)

	def getPeerings(self):
		return Peering.objects.filter(Q(as1=self)|Q(as2=self))

class BorderRouter(models.Model):
	# as id, ip, check method, pingable, reachable
	# unique: (crawl_id, asno, as id)
	AS = models.ForeignKey(AS)
	routerID = models.GenericIPAddressField()
	
	pingable = models.BooleanField(default=False)
	reachable = models.BooleanField(default=False)

	def __unicode__(self):
		p = "p" if self.pingable else "!p"
		r = "r" if self.reachable else "!r"
		return u"Router %s (AS %s, %s%s)" % (self.routerID, self.AS.number, p, r)

class Announcement(models.Model):
	router = models.ForeignKey(BorderRouter)

	ip = models.GenericIPAddressField()
	prefix = models.IntegerField()

	# NOTE: increase length for longer pathes (currently supports a length of ~85)
	ASPath = models.CharField(max_length=512)
	nextHop = models.GenericIPAddressField()
	originAS = models.ForeignKey(AS)

	def __unicode__(self):
		return u"%s/%s via %s (crawl %s)" % (self.ip, self.prefix, self.ASPath, self.router.AS.crawl.pk)

class Peering(models.Model):
	DIRECT = 'direct'
	PATH = 'path'

	ORIGIN = (
		(PATH, 'BGP Path'),
		(DIRECT, 'Direct Connection'),
	)

	as1 =  models.ForeignKey(AS, related_name='peering1')
	as2 = models.ForeignKey(AS, related_name='peering2')
	origin = models.CharField(max_length=10, choices=ORIGIN)

	def __unicode__(self):
		return u"AS %s <--> AS %s (%s, crawl %s)" % (self.as1.number, self.as2.number, self.get_origin_display(), self.as1.crawl.pk)

	def containsAS(self, AS):
		return AS in (self.as1, self.as2)

	@staticmethod
	def getPeering(as1, as2):
		""" Find matching peering """
		try:
			return Peering.objects.get(as1=as1, as2=as2)
		except Peering.DoesNotExist:
			return Peering.objects.get(as1=as2, as2=as1)

class BorderRouterPair(models.Model):
	peering = models.ForeignKey(Peering)
	router1 = models.ForeignKey(BorderRouter, default=None, blank=True, null=True, related_name='routerpair1')
	router2 = models.ForeignKey(BorderRouter, default=None, blank=True, null=True, related_name='routerpair2')

	def __unicode__(self):
		return u"%s <--> %s (crawl %d)" % (self.router1, self.router2, self.router1.AS.crawl.pk)

	@staticmethod
	def getPairing(peering, router1, router2):
		try:
			return BorderRouterPair.objects.get(peering=peering, router1=router1, router2=router2)
		except BorderRouterPair.DoesNotExist:
			return BorderRouterPair.objects.get(peering=peering, router1=router2, router2=router1)