from typing import Any

from django.core.paginator import EmptyPage
from django.core.paginator import Page as PaginatorPage
from django.core.paginator import Paginator
from django.db import models
from django.db.models.functions import TruncMonth
from django.http.request import HttpRequest
from django.http.response import Http404, HttpResponse, HttpResponseBadRequest
from django.utils import timezone
from django.utils.functional import cached_property
from modelcluster.fields import ParentalManyToManyField
from wagtail.admin.panels import FieldPanel
from wagtail.contrib.routable_page.models import RoutablePageMixin, route
from wagtail.query import PageQuerySet

from website.common.models import BaseContentPage
from website.common.serializers import PaginationSerializer
from website.common.utils import TocEntry


class BlogPostListPage(RoutablePageMixin, BaseContentPage):
    max_count = 1
    subpage_types = [
        "blog.BlogPostPage",
        "blog.BlogPostTagListPage",
        "blog.BlogPostCollectionListPage",
        "blog.BlogPostCollectionPage",
    ]

    @cached_property
    def show_reading_time(self) -> bool:
        return False

    @cached_property
    def table_of_contents(self) -> list[TocEntry]:
        post_months = sorted(
            {
                dt.strftime("%Y-%m")
                for dt in self.paginator_page.object_list.annotate(
                    post_month=TruncMonth("date", output_field=models.DateField())
                ).values_list("post_month", flat=True)
            }
        )

        return [TocEntry(post_month, post_month, 0, []) for post_month in post_months]

    def get_blog_posts(self) -> PageQuerySet:
        return BlogPostPage.objects.descendant_of(self).live()

    @cached_property
    def paginator_page(self) -> PaginatorPage:
        pages = (
            self.get_blog_posts()
            .select_related("hero_image")
            .select_related("hero_unsplash_photo")
            .prefetch_related("tags")
            .order_by("-date", "title")
        )
        paginator = Paginator(pages, per_page=1)
        try:
            return paginator.page(self.serializer.validated_data["page"])
        except EmptyPage:
            raise Http404

    def get_context(self, request: HttpRequest) -> dict:
        context = super().get_context(request)
        context["pages"] = self.paginator_page
        return context

    @route(r"^$")
    def index_route(self, request: HttpRequest) -> HttpResponse:
        self.serializer = PaginationSerializer(data=request.GET)
        if not self.serializer.is_valid():
            return HttpResponseBadRequest()
        return super().index_route(request)

    @route(r"^feed/$")
    def feed(self, request: HttpRequest) -> HttpResponse:
        from .views import BlogPostPageFeed

        return BlogPostPageFeed(
            self.get_blog_posts().order_by("-date"), self.get_url(), self.title
        )(request)


class BlogPostPage(BaseContentPage):
    subpage_types: list[Any] = []
    parent_page_types = [BlogPostListPage, "blog.BlogPostCollectionPage"]

    tags = ParentalManyToManyField("blog.BlogPostTagPage", blank=True)
    date = models.DateField(default=timezone.now)

    content_panels = BaseContentPage.content_panels + [
        FieldPanel("date"),
        FieldPanel("tags"),
    ]


class BlogPostTagListPage(BaseContentPage):
    max_count = 1
    parent_page_types = [BlogPostListPage]
    subpage_types = ["blog.BlogPostTagPage"]

    @cached_property
    def table_of_contents(self) -> list[TocEntry]:
        return [TocEntry(page.title, page.slug, 0, []) for page in self.get_tags()]

    def get_tags(self) -> PageQuerySet:
        return (
            self.get_children()
            .specific()
            .live()
            .order_by("title")
            .select_related("hero_image")
            .select_related("hero_unsplash_photo")
        )

    def get_context(self, request: HttpRequest) -> dict:
        context = super().get_context(request)
        context["tags"] = self.get_children().specific().live().order_by("title")
        return context


class BlogPostTagPage(RoutablePageMixin, BaseContentPage):
    subpage_types: list[Any] = []
    parent_page_types = [BlogPostTagListPage]

    @cached_property
    def table_of_contents(self) -> list[TocEntry]:
        return [
            TocEntry(page.title, page.slug, 0, []) for page in self.get_blog_posts()
        ]

    def get_blog_posts(self) -> PageQuerySet:
        blog_list_page = BlogPostListPage.objects.all().live().get()
        return (
            blog_list_page.get_blog_posts()
            .filter(tags=self)
            .order_by("-date")
            .select_related("hero_image")
            .select_related("hero_unsplash_photo")
        )

    def get_context(self, request: HttpRequest) -> dict:
        context = super().get_context(request)
        context["pages"] = self.get_blog_posts()
        return context

    @route(r"^feed/$")
    def feed(self, request: HttpRequest) -> HttpResponse:
        from .views import BlogPostPageFeed

        return BlogPostPageFeed(
            self.get_blog_posts().order_by("-date"), self.get_url(), self.title
        )(request)


class BlogPostCollectionListPage(BaseContentPage):
    subpage_types: list[Any] = []
    parent_page_types = [BlogPostListPage]
    max_count = 1

    @cached_property
    def table_of_contents(self) -> list[TocEntry]:
        return [
            TocEntry(page.title, page.slug, 0, []) for page in self.get_collections()
        ]

    def get_collections(self) -> PageQuerySet:
        blog_list_page = BlogPostListPage.objects.all().live().get()
        return BlogPostCollectionPage.objects.child_of(blog_list_page).live()

    def get_context(self, request: HttpRequest) -> dict:
        context = super().get_context(request)
        context["collections"] = self.get_collections()
        return context


class BlogPostCollectionPage(BaseContentPage):
    parent_page_types = [BlogPostListPage]
    subpage_types = [BlogPostPage]

    @cached_property
    def table_of_contents(self) -> list[TocEntry]:
        return [
            TocEntry(page.title, page.slug, 0, []) for page in self.get_blog_posts()
        ]

    def get_blog_posts(self) -> PageQuerySet:
        return (
            BlogPostPage.objects.child_of(self)
            .order_by("-date")
            .select_related("hero_image")
            .select_related("hero_unsplash_photo")
        )

    def get_context(self, request: HttpRequest) -> dict:
        context = super().get_context(request)
        context["pages"] = self.get_blog_posts()
        return context