from django import forms
from django.contrib import admin
from django.urls import reverse
from django.utils.translation import ugettext as _

from wagtail.contrib.modeladmin.forms import ParentChooserForm
from wagtail.contrib.modeladmin.helpers import PageButtonHelper
from wagtail.contrib.modeladmin.views import ChooseParentView
from wagtail.core.models import Page


class VerboseLabelModelChoiceField(forms.ModelChoiceField):
    def label_from_instance(str, obj):
        return '[{}] {}'.format(obj._meta.verbose_name, obj.title)


class FundChooserForm(ParentChooserForm):
    """Changes the default chooser to be fund orientated """
    parent_page = VerboseLabelModelChoiceField(
        label=_('Fund or RFP'),
        required=True,
        empty_label=None,
        queryset=Page.objects.none(),
        widget=forms.RadioSelect(),
    )


class RoundFundChooserView(ChooseParentView):
    def get_form(self, request):
        parents = self.permission_helper.get_valid_parent_pages(request.user).specific()
        return FundChooserForm(parents, request.POST or None)


class ButtonsWithPreview(PageButtonHelper):
    def preview_button(self, obj, classnames_add, classnames_exclude):
        classnames = self.copy_button_classnames + classnames_add
        cn = self.finalise_classname(classnames, classnames_exclude)
        return {
            'url': reverse('wagtailadmin_pages:view_draft', args=(obj.id,)),
            'label': 'Preview',
            'classname': cn,
            'title': 'Preview this %s' % self.verbose_name,
        }

    def get_buttons_for_obj(self, obj, exclude=list(), classnames_add=list(),
                            classnames_exclude=list()):
        btns = super().get_buttons_for_obj(obj, exclude, classnames_add, classnames_exclude)

        # Put preview before delete
        btns.insert(-1, self.preview_button(obj, classnames_add, classnames_exclude))

        return btns


class FormsFundRoundListFilter(admin.SimpleListFilter):
    title = 'useage'
    parameter_name = 'form-usage'

    def lookups(self, request, model_admin):
        return (
            ('applicationbase', _('Funds & RFP')),
            ('roundbase', _('Rounds and Sealed Rounds')),
            ('labbase', _('Labs')),
        )

    def queryset(self, request, queryset):
        value = self.value()
        if value:
            query = {f'{value}form__isnull': False}
            return queryset.filter(**query).distinct()
        return queryset