#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

from django import forms
from django.utils.translation import ugettext_lazy as _
import netaddr


def fieldset(self, *args, **kwargs):
    """A helper function for grouping fields based on their names."""

    prefix = kwargs.pop('prefix', None)
    names = args or self.fields.keys()
    for name in names:
        if prefix is None or name.startswith(prefix):
            yield forms.forms.BoundField(self, self.fields[name], name)


class NumberInput(forms.widgets.TextInput):
    input_type = 'number'


class NumberPickerInput(NumberInput):
    def __init__(self, attrs=None):
        default_attrs = {'hr-number-picker': '', 'ng-cloak': '', }
        if attrs:
            default_attrs.update(attrs)
        super(NumberPickerInput, self).__init__(default_attrs)


class MACField(forms.fields.Field):
    def clean(self, value):
        class mac_dialect(netaddr.mac_eui48):
            """Same validation as Nova uses."""
            word_fmt = '%.02x'
            word_sep = ':'
        try:
            return str(netaddr.EUI(
                value.strip(), version=48, dialect=mac_dialect)).upper()
        except (netaddr.AddrFormatError, TypeError):
            raise forms.ValidationError(_(u'Enter a valid MAC address.'))


class NetworkField(forms.fields.Field):
    def clean(self, value):
        try:
            return str(netaddr.IPNetwork(value, version=4))
        except netaddr.AddrFormatError:
            raise forms.ValidationError(_("Enter valid IPv4 network address."))