# Copyright (C) 2010, 2011  SPARTA, Inc. dba Cobham Analytic Solutions
# Copyright (C) 2012  SPARTA, Inc. a Parsons Company
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND SPARTA DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS.  IN NO EVENT SHALL SPARTA BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

__version__ = '$Id$'


from django.contrib.auth.models import User
from django import forms
from rpki.resource_set import (resource_range_as, resource_range_ip)
from rpki.gui.app import models
from rpki.exceptions import BadIPResource
from rpki.POW import IPAddress


class AddConfForm(forms.Form):
    handle = forms.CharField(required=True,
            help_text='your handle for your rpki instance')
    run_rpkid = forms.BooleanField(required=False, initial=True,
            label='Run rpkid?',
            help_text='do you want to run your own instance of rpkid?')
    rpkid_server_host = forms.CharField(initial='rpkid.example.org',
            label='rpkid hostname',
            help_text='publicly visible hostname for your rpkid instance')
    rpkid_server_port = forms.IntegerField(initial=4404,
            label='rpkid port')
    run_pubd = forms.BooleanField(required=False, initial=False,
            label='Run pubd?',
            help_text='do you want to run your own instance of pubd?')
    pubd_server_host = forms.CharField(initial='pubd.example.org',
            label='pubd hostname',
            help_text='publicly visible hostname for your pubd instance')
    pubd_server_port = forms.IntegerField(initial=4402, label='pubd port')
    pubd_contact_info = forms.CharField(initial='repo-man@rpki.example.org',
            label='Pubd contact',
            help_text='email address for the operator of your pubd instance')


class GhostbusterRequestForm(forms.ModelForm):
    """
    Generate a ModelForm with the subset of parents for the current
    resource handle.
    """

    # override default form field
    parent = forms.ModelChoiceField(queryset=None, required=False,
            help_text='Specify specific parent, or none for all parents')

    #override
    issuer = forms.ModelChoiceField(queryset=None, widget=forms.HiddenInput)

    def __init__(self, *args, **kwargs):
        conf = kwargs.pop('conf')
        # override initial value for conf in case user tries to alter it
        initial = kwargs.setdefault('initial', {})
        initial['issuer'] = conf
        super(GhostbusterRequestForm, self).__init__(*args, **kwargs)
        self.fields['parent'].queryset = conf.parents.all()
        self.fields['issuer'].queryset = models.Conf.objects.filter(pk=conf.pk)

    class Meta:
        model = models.GhostbusterRequest
        exclude = ('vcard', 'given_name', 'family_name', 'additional_name',
                   'honorific_prefix', 'honorific_suffix')

    def clean(self):
        email = self.cleaned_data.get('email_address')
        postal = self.cleaned_data.get('postal_address')
        telephone = self.cleaned_data.get('telephone')
        if not any([email, postal, telephone]):
            raise forms.ValidationError(
                'One of telephone, email or postal address must be specified')

        return self.cleaned_data


class ImportForm(forms.Form):
    """Form used for uploading parent/child identity xml files."""

    handle = forms.CharField(required=False,
                             widget=forms.TextInput(attrs={'class': 'xlarge'}),
                             help_text='Optional.  Your name for this entity, or blank to accept name in XML')
    xml = forms.FileField(label='XML file')


class ImportRepositoryForm(forms.Form):
    handle = forms.CharField(max_length=30, required=False,
                             label='Parent Handle',
                             help_text='Optional.  Must be specified if you use a different name for this parent')
    xml = forms.FileField(label='XML file')


class ImportClientForm(forms.Form):
    """Form used for importing publication client requests."""

    xml = forms.FileField(label='XML file')


class ImportCSVForm(forms.Form):
    csv = forms.FileField(label='CSV file')


class UserCreateForm(forms.Form):
    username = forms.CharField(max_length=30)
    email = forms.CharField(max_length=30,
                            help_text='email address for new user')
    password = forms.CharField(widget=forms.PasswordInput)
    password2 = forms.CharField(widget=forms.PasswordInput,
                                label='Confirm Password')
    resource_holders = forms.ModelMultipleChoiceField(
        queryset=models.Conf.objects.all(),
        help_text='allowed to manage these resource holders'

    )

    def clean_username(self):
        username = self.cleaned_data.get('username')
        if User.objects.filter(username=username).exists():
            raise forms.ValidationError('user already exists')
        return username

    def clean(self):
        p1 = self.cleaned_data.get('password')
        p2 = self.cleaned_data.get('password2')
        if p1 != p2:
            raise forms.ValidationError('passwords do not match')
        return self.cleaned_data


class UserEditForm(forms.Form):
    """Form for editing a user."""

    email = forms.CharField()
    pw = forms.CharField(widget=forms.PasswordInput, label='Password',
                         required=False)
    pw2 = forms.CharField(widget=forms.PasswordInput, label='Confirm password',
                          required=False)
    resource_holders = forms.ModelMultipleChoiceField(
        queryset=models.Conf.objects.all(),
        help_text='allowed to manage these resource holders'
    )

    def clean(self):
        p1 = self.cleaned_data.get('pw')
        p2 = self.cleaned_data.get('pw2')
        if p1 != p2:
            raise forms.ValidationError('Passwords do not match')
        return self.cleaned_data


class ROARequest(forms.Form):
    """Form for entering a ROA request.

    Handles both IPv4 and IPv6."""

    prefix = forms.CharField(
        widget=forms.TextInput(attrs={
            'autofocus': 'true', 'placeholder': 'Prefix',
            'class': 'span4'
        })
    )
    max_prefixlen = forms.CharField(
        required=False,
        widget=forms.TextInput(attrs={
            'placeholder': 'Max len',
            'class': 'span1'
        })
    )
    asn = forms.IntegerField(
        widget=forms.TextInput(attrs={
            'placeholder': 'ASN',
            'class': 'span1'
        })
    )
    confirmed = forms.BooleanField(widget=forms.HiddenInput, required=False)

    def __init__(self, *args, **kwargs):
        """Takes an optional `conf` keyword argument specifying the user that
        is creating the ROAs.  It is used for validating that the prefix the
        user entered is currently allocated to that user.
        """

        conf = kwargs.pop('conf', None)
        kwargs['auto_id'] = False
        super(ROARequest, self).__init__(*args, **kwargs)
        self.conf = conf
        self.inline = True
        self.use_table = False

    def _as_resource_range(self):
        """Convert the prefix in the form to a
        rpki.resource_set.resource_range_ip object.

        If there is no mask provided, assume the closest classful mask.
        """

        prefix = self.cleaned_data.get('prefix')
        if '/' not in prefix:
            p = IPAddress(prefix)

            # determine the first nonzero bit starting from the lsb and
            # subtract from the address size to find the closest classful
            # mask that contains this single address
            prefixlen = 0
            while (p != 0) and (p & 1) == 0:
                prefixlen = prefixlen + 1
                p = p >> 1
            mask = p.bits - (8 * (prefixlen / 8))
            prefix = prefix + '/' + str(mask)

        return resource_range_ip.parse_str(prefix)

    def clean_asn(self):
        value = self.cleaned_data.get('asn')
        if value < 0:
            raise forms.ValidationError('AS must be a positive value or 0')
        return value

    def clean_prefix(self):
        try:
            r = self._as_resource_range()
        except:
            raise forms.ValidationError('invalid prefix')

        manager = models.ResourceRangeAddressV4 if r.version == 4 else models.ResourceRangeAddressV6
        if not manager.objects.filter(cert__conf=self.conf,
                                      prefix_min__lte=r.min,
                                      prefix_max__gte=r.max).exists():
            raise forms.ValidationError('prefix is not allocated to you')
        return str(r)

    def clean_max_prefixlen(self):
        v = self.cleaned_data.get('max_prefixlen')
        if v:
            if v[0] == '/':
                v = v[1:]  # allow user to specify /24
            try:
                if int(v) < 0:
                    raise forms.ValidationError('max prefix length must be positive or 0')
            except ValueError:
                raise forms.ValidationError('invalid integer value')
        return v

    def clean(self):
        if 'prefix' in self.cleaned_data:
            r = self._as_resource_range()
            max_prefixlen = self.cleaned_data.get('max_prefixlen')
            max_prefixlen = int(max_prefixlen) if max_prefixlen else r.prefixlen()
            if max_prefixlen < r.prefixlen():
                raise forms.ValidationError(
                    'max prefix length must be greater than or equal to the prefix length')
            if max_prefixlen > r.min.bits:
                raise forms.ValidationError(
                        'max prefix length (%d) is out of range for IP version (%d)' % (max_prefixlen, r.min.bits))
            self.cleaned_data['max_prefixlen'] = str(max_prefixlen)
        return self.cleaned_data


class ROARequestConfirm(forms.Form):
    asn = forms.IntegerField(widget=forms.HiddenInput)
    prefix = forms.CharField(widget=forms.HiddenInput)
    max_prefixlen = forms.IntegerField(widget=forms.HiddenInput)

    def clean_asn(self):
        value = self.cleaned_data.get('asn')
        if value < 0:
            raise forms.ValidationError('AS must be a positive value or 0')
        return value

    def clean_prefix(self):
        try:
            r = resource_range_ip.parse_str(self.cleaned_data.get('prefix'))
        except BadIPResource:
            raise forms.ValidationError('invalid prefix')
        return str(r)

    def clean(self):
        try:
            r = resource_range_ip.parse_str(self.cleaned_data.get('prefix'))
            if r.prefixlen() > self.cleaned_data.get('max_prefixlen'):
                raise forms.ValidationError('max length is smaller than mask')
        except BadIPResource:
            pass
        return self.cleaned_data


class AddASNForm(forms.Form):
    """
    Returns a forms.Form subclass which verifies that the entered ASN range
    does not overlap with a previous allocation to the specified child, and
    that the ASN range is within the range allocated to the parent.
    """

    asns = forms.CharField(
        label='ASNs',
        help_text='single ASN or range',
        widget=forms.TextInput(attrs={'autofocus': 'true'})
    )

    def __init__(self, *args, **kwargs):
        self.child = kwargs.pop('child')
        super(AddASNForm, self).__init__(*args, **kwargs)

    def clean_asns(self):
        try:
            r = resource_range_as.parse_str(self.cleaned_data.get('asns'))
        except:
            raise forms.ValidationError('invalid AS or range')

        if not models.ResourceRangeAS.objects.filter(
            cert__conf=self.child.issuer,
            min__lte=r.min,
            max__gte=r.max).exists():
            raise forms.ValidationError('AS or range is not delegated to you')

        # determine if the entered range overlaps with any AS already
        # allocated to this child
        if self.child.asns.filter(end_as__gte=r.min, start_as__lte=r.max).exists():
            raise forms.ValidationError(
                'Overlap with previous allocation to this child')

        return str(r)


class AddNetForm(forms.Form):
    """
    Returns a forms.Form subclass which validates that the entered address
    range is within the resources allocated to the parent, and does not overlap
    with what is already allocated to the specified child.
    """

    address_range = forms.CharField(
        help_text='CIDR or range',
        widget=forms.TextInput(attrs={'autofocus': 'true'})
    )

    def __init__(self, *args, **kwargs):
        self.child = kwargs.pop('child')
        super(AddNetForm, self).__init__(*args, **kwargs)

    def clean_address_range(self):
        address_range = self.cleaned_data.get('address_range')
        try:
            r = resource_range_ip.parse_str(address_range)
            if r.version == 6:
                qs = models.ResourceRangeAddressV6
                version = 'IPv6'
            else:
                qs = models.ResourceRangeAddressV4
                version = 'IPv4'
        except BadIPResource:
            raise forms.ValidationError('invalid IP address range')

        if not qs.objects.filter(cert__conf=self.child.issuer,
                                 prefix_min__lte=r.min,
                                 prefix_max__gte=r.max).exists():
            raise forms.ValidationError(
                'IP address range is not delegated to you')

        # determine if the entered range overlaps with any prefix
        # already allocated to this child
        for n in self.child.address_ranges.filter(version=version):
            rng = n.as_resource_range()
            if r.max >= rng.min and r.min <= rng.max:
                raise forms.ValidationError(
                    'Overlap with previous allocation to this child')

        return str(r)


def ChildForm(instance):
    """
    Form for editing a Child model.

    This is roughly based on the equivalent ModelForm, but uses Form as a base
    class so that selection boxes for the AS and Prefixes can be edited in a
    single form.
    """

    class _wrapped(forms.Form):
        valid_until = forms.DateTimeField(initial=instance.valid_until)
        as_ranges = forms.ModelMultipleChoiceField(queryset=models.ChildASN.objects.filter(child=instance),
                                                   required=False,
                                                   label='AS Ranges',
                                                   help_text='deselect to remove delegation')
        address_ranges = forms.ModelMultipleChoiceField(queryset=models.ChildNet.objects.filter(child=instance),
                                                        required=False,
                                                        help_text='deselect to remove delegation')

    return _wrapped


class Empty(forms.Form):
    """Stub form for views requiring confirmation."""

    pass


class ResourceHolderForm(forms.Form):
    """form for editing ACL on Conf objects."""

    users = forms.ModelMultipleChoiceField(
        queryset=User.objects.all(),
        help_text='users allowed to mange this resource holder'
    )


class ResourceHolderCreateForm(forms.Form):
    """form for creating new resource holders."""

    handle = forms.CharField(max_length=30)
    parent = forms.ModelChoiceField(
        required=False,
        queryset=models.Conf.objects.all(),
        help_text='optionally make the new resource holder a child of this resource holder'
    )
    users = forms.ModelMultipleChoiceField(
        required=False,
        queryset=User.objects.all(),
        help_text='users allowed to mange this resource holder'
    )

    def clean_handle(self):
        handle = self.cleaned_data.get('handle')
        if models.Conf.objects.filter(handle=handle).exists():
            raise forms.ValidationError(
                'a resource holder with that handle already exists'
            )
        return handle

    def clean(self):
        handle = self.cleaned_data.get('handle')
        parent = self.cleaned_data.get('parent')
        if handle and parent and parent.children.filter(handle=handle).exists():
            raise forms.ValidationError('parent already has a child by that name')
        return self.cleaned_data


class RouterCertificateRequestForm(forms.Form):
    """form for uploading router cert request"""
    xml = forms.FileField(label='XML file')