from __future__ import absolute_import, unicode_literals

from django import forms
from django.forms.models import inlineformset_factory
from django.utils.translation import ugettext_lazy as _

from wagtail.contrib.wagtailsearchpromotions.models import SearchPromotion
from wagtail.wagtailadmin.widgets import AdminPageChooser
from wagtail.wagtailsearch.models import Query


class SearchPromotionForm(forms.ModelForm):
    sort_order = forms.IntegerField(required=False)

    def __init__(self, *args, **kwargs):
        super(SearchPromotionForm, self).__init__(*args, **kwargs)
        self.fields['page'].widget = AdminPageChooser()

    class Meta:
        model = SearchPromotion
        fields = ('query', 'page', 'description')

        widgets = {
            'description': forms.Textarea(attrs=dict(rows=3)),
        }


SearchPromotionsFormSetBase = inlineformset_factory(
    Query, SearchPromotion, form=SearchPromotionForm, can_order=True, can_delete=True, extra=0
)


class SearchPromotionsFormSet(SearchPromotionsFormSetBase):
    minimum_forms = 1
    minimum_forms_message = _("Please specify at least one recommendation for this search term.")

    def add_fields(self, form, *args, **kwargs):
        super(SearchPromotionsFormSet, self).add_fields(form, *args, **kwargs)

        # Hide delete and order fields
        form.fields['DELETE'].widget = forms.HiddenInput()
        form.fields['ORDER'].widget = forms.HiddenInput()

        # Remove query field
        del form.fields['query']

    def clean(self):
        # Search pick must have at least one recommended page to be valid
        # Check there is at least one non-deleted form.
        non_deleted_forms = self.total_form_count()
        non_empty_forms = 0
        for i in range(0, self.total_form_count()):
            form = self.forms[i]
            if self.can_delete and self._should_delete_form(form):
                non_deleted_forms -= 1
            if not (form.instance.id is None and not form.has_changed()):
                non_empty_forms += 1
        if (
            non_deleted_forms < self.minimum_forms or
            non_empty_forms < self.minimum_forms
        ):
            raise forms.ValidationError(self.minimum_forms_message)
