from __future__ import unicode_literals

from django import forms
from django.db.models import Count

from dcim.models import Site, Device, Interface, Rack, VIRTUAL_IFACE_TYPES
from extras.forms import CustomFieldForm, CustomFieldBulkEditForm, CustomFieldFilterForm
from tenancy.forms import TenancyForm
from tenancy.models import Tenant
from utilities.forms import (
    APISelect, BootstrapMixin, ChainedFieldsMixin, ChainedModelChoiceField, CommentField, FilterChoiceField,
    SmallTextarea, SlugField,
)

from .models import Circuit, CircuitTermination, CircuitType, Provider


#
# Providers
#

class ProviderForm(BootstrapMixin, CustomFieldForm):
    slug = SlugField()
    comments = CommentField()

    class Meta:
        model = Provider
        fields = ['name', 'slug', 'asn', 'account', 'portal_url', 'noc_contact', 'admin_contact', 'comments']
        widgets = {
            'noc_contact': SmallTextarea(attrs={'rows': 5}),
            'admin_contact': SmallTextarea(attrs={'rows': 5}),
        }
        help_texts = {
            'name': "Full name of the provider",
            'asn': "BGP autonomous system number (if applicable)",
            'portal_url': "URL of the provider's customer support portal",
            'noc_contact': "NOC email address and phone number",
            'admin_contact': "Administrative contact email address and phone number",
        }


class ProviderCSVForm(forms.ModelForm):
    slug = SlugField()

    class Meta:
        model = Provider
        fields = ['name', 'slug', 'asn', 'account', 'portal_url', 'comments']
        help_texts = {
            'name': 'Provider name',
            'asn': '32-bit autonomous system number',
            'portal_url': 'Portal URL',
            'comments': 'Free-form comments',
        }


class ProviderBulkEditForm(BootstrapMixin, CustomFieldBulkEditForm):
    pk = forms.ModelMultipleChoiceField(queryset=Provider.objects.all(), widget=forms.MultipleHiddenInput)
    asn = forms.IntegerField(required=False, label='ASN')
    account = forms.CharField(max_length=30, required=False, label='Account number')
    portal_url = forms.URLField(required=False, label='Portal')
    noc_contact = forms.CharField(required=False, widget=SmallTextarea, label='NOC contact')
    admin_contact = forms.CharField(required=False, widget=SmallTextarea, label='Admin contact')
    comments = CommentField(widget=SmallTextarea)

    class Meta:
        nullable_fields = ['asn', 'account', 'portal_url', 'noc_contact', 'admin_contact', 'comments']


class ProviderFilterForm(BootstrapMixin, CustomFieldFilterForm):
    model = Provider
    q = forms.CharField(required=False, label='Search')
    site = FilterChoiceField(queryset=Site.objects.all(), to_field_name='slug')
    asn = forms.IntegerField(required=False, label='ASN')


#
# Circuit types
#

class CircuitTypeForm(BootstrapMixin, forms.ModelForm):
    slug = SlugField()

    class Meta:
        model = CircuitType
        fields = ['name', 'slug']


#
# Circuits
#

class CircuitForm(BootstrapMixin, TenancyForm, CustomFieldForm):
    comments = CommentField()

    class Meta:
        model = Circuit
        fields = [
            'cid', 'type', 'provider', 'install_date', 'commit_rate', 'description', 'tenant_group', 'tenant',
            'comments',
        ]
        help_texts = {
            'cid': "Unique circuit ID",
            'install_date': "Format: YYYY-MM-DD",
            'commit_rate': "Committed rate",
        }


class CircuitCSVForm(forms.ModelForm):
    provider = forms.ModelChoiceField(
        queryset=Provider.objects.all(),
        to_field_name='name',
        help_text='Name of parent provider',
        error_messages={
            'invalid_choice': 'Provider not found.'
        }
    )
    type = forms.ModelChoiceField(
        queryset=CircuitType.objects.all(),
        to_field_name='name',
        help_text='Name of circuit type',
        error_messages={
            'invalid_choice': 'Invalid circuit type.'
        }
    )
    tenant = forms.ModelChoiceField(
        queryset=Tenant.objects.all(),
        required=False,
        to_field_name='name',
        help_text='Name of assigned tenant',
        error_messages={
            'invalid_choice': 'Tenant not found.'
        }
    )

    class Meta:
        model = Circuit
        fields = ['cid', 'provider', 'type', 'tenant', 'install_date', 'commit_rate', 'description', 'comments']


class CircuitBulkEditForm(BootstrapMixin, CustomFieldBulkEditForm):
    pk = forms.ModelMultipleChoiceField(queryset=Circuit.objects.all(), widget=forms.MultipleHiddenInput)
    type = forms.ModelChoiceField(queryset=CircuitType.objects.all(), required=False)
    provider = forms.ModelChoiceField(queryset=Provider.objects.all(), required=False)
    tenant = forms.ModelChoiceField(queryset=Tenant.objects.all(), required=False)
    commit_rate = forms.IntegerField(required=False, label='Commit rate (Kbps)')
    description = forms.CharField(max_length=100, required=False)
    comments = CommentField(widget=SmallTextarea)

    class Meta:
        nullable_fields = ['tenant', 'commit_rate', 'description', 'comments']


class CircuitFilterForm(BootstrapMixin, CustomFieldFilterForm):
    model = Circuit
    q = forms.CharField(required=False, label='Search')
    type = FilterChoiceField(
        queryset=CircuitType.objects.annotate(filter_count=Count('circuits')),
        to_field_name='slug'
    )
    provider = FilterChoiceField(
        queryset=Provider.objects.annotate(filter_count=Count('circuits')),
        to_field_name='slug'
    )
    tenant = FilterChoiceField(
        queryset=Tenant.objects.annotate(filter_count=Count('circuits')),
        to_field_name='slug',
        null_option=(0, 'None')
    )
    site = FilterChoiceField(
        queryset=Site.objects.annotate(filter_count=Count('circuit_terminations')),
        to_field_name='slug'
    )


#
# Circuit terminations
#

class CircuitTerminationForm(BootstrapMixin, ChainedFieldsMixin, forms.ModelForm):
    site = forms.ModelChoiceField(
        queryset=Site.objects.all(),
        widget=forms.Select(
            attrs={'filter-for': 'rack'}
        )
    )
    rack = ChainedModelChoiceField(
        queryset=Rack.objects.all(),
        chains=(
            ('site', 'site'),
        ),
        required=False,
        label='Rack',
        widget=APISelect(
            api_url='/api/dcim/racks/?site_id={{site}}',
            attrs={'filter-for': 'device', 'nullable': 'true'}
        )
    )
    device = ChainedModelChoiceField(
        queryset=Device.objects.all(),
        chains=(
            ('site', 'site'),
            ('rack', 'rack'),
        ),
        required=False,
        label='Device',
        widget=APISelect(
            api_url='/api/dcim/devices/?site_id={{site}}&rack_id={{rack}}',
            display_field='display_name',
            attrs={'filter-for': 'interface'}
        )
    )
    interface = ChainedModelChoiceField(
        queryset=Interface.objects.exclude(form_factor__in=VIRTUAL_IFACE_TYPES).select_related(
            'circuit_termination', 'connected_as_a', 'connected_as_b'
        ),
        chains=(
            ('device', 'device'),
        ),
        required=False,
        label='Interface',
        widget=APISelect(
            api_url='/api/dcim/interfaces/?device_id={{device}}&type=physical',
            disabled_indicator='is_connected'
        )
    )

    class Meta:
        model = CircuitTermination
        fields = [
            'term_side', 'site', 'rack', 'device', 'interface', 'port_speed', 'upstream_speed', 'xconnect_id',
            'pp_info',
        ]
        help_texts = {
            'port_speed': "Physical circuit speed",
            'xconnect_id': "ID of the local cross-connect",
            'pp_info': "Patch panel ID and port number(s)"
        }
        widgets = {
            'term_side': forms.HiddenInput(),
        }

    def __init__(self, *args, **kwargs):

        # Initialize helper selectors
        instance = kwargs.get('instance')
        if instance and instance.interface is not None:
            initial = kwargs.get('initial', {})
            initial['rack'] = instance.interface.device.rack
            initial['device'] = instance.interface.device
            kwargs['initial'] = initial

        super(CircuitTerminationForm, self).__init__(*args, **kwargs)

        # Mark connected interfaces as disabled
        self.fields['interface'].choices = [
            (iface.id, {'label': iface.name, 'disabled': iface.is_connected}) for iface in self.fields['interface'].queryset
        ]