website/website/blog/models.py

from typing import Any, Type

from django.db import models
from django.db.models.functions import TruncMonth
from django.utils import timezone
from django.utils.functional import cached_property
from modelcluster.fields import ParentalManyToManyField
from wagtail.admin.panels import FieldPanel

from website.common.models import BaseContentPage, BaseListingPage
from website.common.utils import TocEntry
from website.common.views import ContentPageFeed


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

    @cached_property
    def table_of_contents(self) -> list[TocEntry]:
        post_months = sorted(
            {
                dt.strftime("%Y-%m")
                for dt in self.get_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_listing_pages(self) -> models.QuerySet:
        return (
            BlogPostPage.objects.descendant_of(self)
            .live()
            .select_related("hero_image")
            .select_related("hero_unsplash_photo")
            .prefetch_related("tags")
            .order_by("-date", "title")
        )

    @property
    def feed_class(self) -> Type[ContentPageFeed]:
        from .views import BlogPostPageFeed

        return BlogPostPageFeed


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(BaseListingPage):
    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_listing_pages()
        ]


class BlogPostTagPage(BaseListingPage):
    subpage_types: list[Any] = []
    parent_page_types = [BlogPostTagListPage]

    def get_listing_pages(self) -> models.QuerySet:
        blog_list_page = BlogPostListPage.objects.all().live().get()
        return blog_list_page.get_listing_pages().filter(tags=self)

    @property
    def feed_class(self) -> Type[ContentPageFeed]:
        from .views import BlogPostPageFeed

        return BlogPostPageFeed


class BlogPostCollectionListPage(BaseListingPage):
    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_listing_pages()
        ]

    def get_listing_pages(self) -> models.QuerySet:
        blog_list_page = BlogPostListPage.objects.all().live().get()
        return BlogPostCollectionPage.objects.child_of(blog_list_page).live()


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

    def get_listing_pages(self) -> models.QuerySet:
        return super().get_listing_pages().order_by("-date")

    @property
    def feed_class(self) -> Type[ContentPageFeed]:
        from .views import BlogPostPageFeed

        return BlogPostPageFeed