from re import Pattern

from django.db import models
from django.db.models import When, Case, Value
from remote_resources.raw_items.admin import RawItemAdmin
from remote_resources.raw_items.models import RawItemInterface
from remote_resources.raw_items.querysets import RawItemQuerySet

from webclipper.abstracts import WebClipInterface
from webclipper.admin import WebClipAdmin
from webclipper.utils import simplify_regex_named_groups


class WebClipRawItemQuerySet(RawItemQuerySet):
    def _bulk_update_processed_item(self, processed_raw_items):
        return self.bulk_update(processed_raw_items, ('_pi_content_type', '_pi_object_id'))

    def annotate_is_processed(self):
        return self.annotate(is_processed=Case(
            When(_pi_object_id__isnull=False, then=Value(True)),
            default=Value(False),
            output_field=models.BooleanField()
        ))

    def filter_relevant(self):
        return self.filter(page_url__regex=self.model._get_url_regex_for_db())


class WebClipRawItemManager(models.Manager):
    def _get_queryset_class(self):
        return getattr(self.model, 'queryset_cls', WebClipRawItemQuerySet)

    def get_queryset(self):
        qs_cls = self._get_queryset_class()
        return qs_cls(self.model, self._db).filter_relevant()


class AbstractWebClipRawItem(WebClipInterface, RawItemInterface, models.Model):
    class Meta:
        abstract = True

    @property
    def raw(self):
        return self.html_content

    url_regex: Pattern[str]

    def is_valid(self):
        return bool(self.url_regex.match(self.page_url))

    @classmethod
    def _get_url_regex_for_db(cls):
        return simplify_regex_named_groups(cls.url_regex.pattern)

    objects = WebClipRawItemManager()


class WebClipRawItemAdmin(RawItemAdmin, WebClipAdmin):
    list_display = (*WebClipAdmin.list_display, 'is_processed')
    readonly_fields = (
        *RawItemAdmin.readonly_fields,
        *WebClipAdmin.readonly_fields,
    )
    fieldsets = (
        *WebClipAdmin.fieldsets[:2],
        ("Processing", {'fields': ('processed_item_display', 'is_processed')}),
        *WebClipAdmin.fieldsets[3:],
    )

    scraped_fields = None

    def get_readonly_fields(self, request, obj=None):
        readonly_fields = super().get_readonly_fields(request, obj)
        if self.scraped_fields is not None:
            readonly_fields = (
                *readonly_fields,
                *self.scraped_fields,
            )
        return readonly_fields

    def get_fieldsets(self, request, obj=None):
        fieldsets = super().get_fieldsets(request, obj)
        if fieldsets and self.scraped_fields is not None:
            fieldsets = (
                *fieldsets[:2],
                ("Scraped", {'fields': self.scraped_fields}),
                *fieldsets[2:],
            )
        return fieldsets


__all__ = (
    'WebClipRawItemQuerySet',
    'WebClipRawItemManager',
    'AbstractWebClipRawItem',
    'WebClipRawItemAdmin',
)