from django import forms

#from crispy_forms.helper import FormHelper
#from crispy_forms.layout import Submit, Layout
#from django.urls import reverse

from .models import Maintainer, Contact, InetNum

import re
import ipaddress


class WhoisObjectMixin(object):
	def __init__(self, user, *args, **kwargs):
		super(WhoisObjectMixin, self).__init__(*args, **kwargs)
		self._user = user

		instance = getattr(self, 'instance', None)
		if instance and instance.pk:
			self.fields['handle'].widget.attrs['readonly'] = True

	def clean_handle(self):
		instance = getattr(self, 'instance', None)
		if instance and instance.pk:
			return instance.handle
		else:
			return self.cleaned_data['handle']

	def clean(self):
		cleaned_data = super(WhoisObjectMixin, self).clean()
		if cleaned_data.get("handle") == "AUTO" and not self.errors:
			cleaned_data['handle'] = self._meta.model.genGenericHandle(cleaned_data.get("name"))

		return cleaned_data


class MntForm(forms.ModelForm):
	class Meta:
		model = Maintainer
		fields = ['handle', 'description', 'admin_c']

	def __init__(self, user, *args, **kwargs):
		super(MntForm, self).__init__(*args, **kwargs)
		self._user = user
		if 'admin_c' in self.fields:
			self.fields['admin_c'].queryset = Contact.objects.filter(mnt_by=user.maintainer_set.all())


class MntInitialForm(MntForm):
	class Meta:
		model = Maintainer
		fields = ['handle', 'description']


class ContactForm(WhoisObjectMixin, forms.ModelForm):
	class Meta:
		model = Contact
		fields = ['type', 'handle', 'name', 'mnt_by']

	def __init__(self, *args, **kwargs):
		super(ContactForm, self).__init__(*args, **kwargs)


class ContactInitialForm(ContactForm):
	class Meta:
		model = Contact
		fields = ['handle', 'name']


class InetNumForm(WhoisObjectMixin, forms.ModelForm):
	prefix = forms.CharField()
	protectedFields = ['handle', 'protocol', 'parent_range', 'mnt_by', 'prefix']

	class Meta:
		model = InetNum
		fields = ['handle', 'protocol', 'parent_range', 'prefix', 'name', 'description', 'mnt_by', 'mnt_lower']

	def __init__(self, lower=False, *args, **kwargs):
		super(InetNumForm, self).__init__(*args, **kwargs)
		print("args", args, kwargs)
		self._editLower = lower
		if 'admin_c' in self.fields:
			self.fields['admin_c'].queryset = Contact.objects.filter(mnt_by__in=self.user.maintainer_set.all())

		if self._editLower:
			for key in self.protectedFields:
				self.fields[key].disabled = True
				self.fields[key].widget.attrs['readonly'] = False

	def clean_prefix(self):
		# make sure this is a subnet we're getting
		print("HALLO")
		net = self.cleaned_data['prefix']
		if not re.match(r"[0-9:.]+/[0-9]+", net):
			raise forms.ValidationError("Address needs to be a subnet in the format of ip/cidr")
		try:
			net = ipaddress.ip_network(net)
		except ValueError as e:
			raise forms.ValidationError(str(e))

		return net

	def clean(self):
		# FIXME: Reset certain field sto instance:
		cleaned_data = super(InetNumForm, self).clean()
		if self._editLower:
			# reset some fields, just in case
			#for key in self.protectedFields:
			#	cleaned_data[key] = getattr(self.instance, key)
			pass
		else:
			if all(x in cleaned_data for x in ('prefix', 'parent_range', 'protocol')):
				prefix = cleaned_data['prefix']
				parent = cleaned_data['parent_range']
				parentNet = parent.getNetwork()

				if cleaned_data['protocol'] != parent.protocol:
					raise forms.ValidationError("Protocol type for prefix must be same as parent network")

				# check if in parent block
				if prefix.network_address not in parentNet or prefix.prefixlen < parentNet.prefixlen:
					raise forms.ValidationError("Prefix must be inside parent network range")

				# check if parent block has net that overlaps with us
				for otherNet in parent.inetnum_set.all():
					if self.instance and self.instance.pk == otherNet.pk:
						continue

					if otherNet.getNetwork().overlaps(prefix):
						raise forms.ValidationError("The given prefix overlaps with network %s" % otherNet.handle)

				self.instance.address = str(prefix.network_address)
				self.instance.netmask = prefix.prefixlen

		return cleaned_data