# This file is part of dnmgmt, a number resource management system
# Licensed under GNU General Public License v3 or later
# Written by Sebastian Lohff (seba@someserver.de)

import whoisdb.models
import domains.models

from django.db.models import F, When, Max, Case, IntegerField

import ipaddress
import re

def _addFields(fields, obj, fieldNames):
	for fieldName in fieldNames:
		fields.append((fieldName.capitalize().replace("_", " "), getattr(obj, fieldName)))


def getWhoisObjectFields(obj, owner):
	fields = []

	if getattr(obj, "handle", None):
		_addFields(fields, obj, ["handle"])

	c = type(obj)
	if c == whoisdb.models.Maintainer:
		_addFields(fields, obj, ["description", "admin_c"])
		if owner:
			_addFields(fields, obj, ["auth"])
	elif c == whoisdb.models.Contact:
		_addFields(fields, obj, ["name", "mnt_by"])
	elif c == whoisdb.models.ASBlock:
		_addFields(fields, obj, ["name"])
		fields.append(("AS Range", "%s - %s" % (obj.asBegin, obj.asEnd)))
		_addFields(fields, obj, ["description", "parent_block", "mnt_by", "mnt_lower", "admin_c"])
	elif c == whoisdb.models.ASNumber:
		_addFields(fields, obj, ["name", "number", "description", "asblock", "volatile", "mnt_by", "mnt_lower", "admin_c"])
	elif c == whoisdb.models.InetNum:
		_addFields(fields, obj, ["name"])
		fields.append(("Address CIDR", obj.prefix()))
		_addFields(fields, obj, ["description", "parent_range", "origin_as", "mnt_by", "mnt_lower", "admin_c"])
	elif c == domains.models.Domain:
		_addFields(fields, obj, ["name", "nameservers", "mnt_by", "admin_c"])
	elif c == domains.models.Nameserver:
		_addFields(fields, obj, ["name", "glueIPv4", "glueIPv6", "mnt_by", "admin_c"])
	elif c == domains.models.ReverseZone:
		#_addFields(fields, obj, ["name"])
		fields.append(("Address CIDR", obj.prefix()))
		_addFields(fields, obj, ["parentNet", "nameservers"])

	_addFields(fields, obj, ["created", "last_modified"])

	return fields


def guessWhoisObject(self, handle):
	# is it a normal handle?
	pass

def findInDatabase(rawValue):
	# is this an ip address?
	rawValue = rawValue.strip().upper()
	value = None
	results = []

	# try subnetwork
	try:
		value = ipaddress.ip_network(rawValue, strict=False)
	except ValueError:
		pass

	if value:
		# ssubnet
		obj = whoisdb.models.InetNum.objects.filter(address=str(value.network_address), netmask=value.prefixlen)
		results.extend(obj)

	# single ip
	value = None
	try:
		value = ipaddress.ip_address(rawValue)
	except ValueError:
		pass

	if value:
		# NOTE: this is only for "small subnets", we could increase this...
		baseaddr = None
		if value.version == 4:
			basenet = ipaddress.ip_network("%s/24" % value, strict=False)
			baseaddr = ".".join(str(basenet).split(".")[0:3]) + "."
		else:
			basenet = ipaddress.ip_network("%s/56" % value.exploded, strict=False)
			baseaddr = ":".join(str(basenet).split(":")[0:4])[-2]

		nets = whoisdb.models.InetNum.objects.filter(address__startswith=baseaddr).order_by("-netmask")
		for net in nets:
			if value in net.getNetwork():
				results.append(net)
				break

	# asnumber?
	m = re.match("^(?:AS)?(\d+)$", rawValue)
	if m:
		# asnumber!
		num = int(m.group(1))
		obj = whoisdb.models.ASNumber.objects.filter(number=num)
		results.extend(obj)

		# find a matching block
		blocks = whoisdb.models.ASBlock.objects.filter(asBegin__lte=num, asEnd__gte=num).annotate(size=F('asEnd')-F('asBegin')).order_by('size')
		if blocks.count() > 0:
			results.append(blocks[0])

	# asblocks? smallest asblock containing the range
	# WHEN anotation foo... could also be done in asnumber match
	# also look for number - number queries?

	# domain?
	if rawValue.endswith("DN") or rawValue.endswith("DN."):
		value = rawValue.lower()
		if not value.endswith("."):
			value += "."

		obj = domains.models.Domain.objects.filter(name=value)
		results.extend(obj)

	# contact by name?

	# handlenames for Maintainer, Contact, InetNum, ASNumber, ASBlock
	handleObjs = [
		whoisdb.models.Contact,
		whoisdb.models.Maintainer,
		whoisdb.models.InetNum,
		whoisdb.models.ASBlock,
		whoisdb.models.ASNumber,
	]
	for handleObj in handleObjs:
		obj = handleObj.objects.filter(handle=rawValue)
		if not obj and len(rawValue) >= 3:
			obj = handleObj.objects.filter(handle__startswith=rawValue)
		results.extend(obj)

	return results

def findHandleFromStr(rawValue):
	handleObjs = [
		whoisdb.models.Contact,
		whoisdb.models.Maintainer,
		whoisdb.models.InetNum,
		whoisdb.models.ASBlock,
		whoisdb.models.ASNumber,
	]

	for handleObj in handleObjs:
		try:
			return handleObj.objects.get(handle=rawValue)
		except handleObj.DoesNotExist:
			pass

	return None


def orderQueryset(qs, userOwned, objOwned):
	# when for 
	whens = [When(userOwned, then=2)]
	if objOwned:
		# add existing
		whens.append(When(objOwned, then=1))

	qs = qs.annotate(card=Max(Case(*whens, default=0, output_field=IntegerField()))).order_by("-card")

	return qs