website/website/blog/models.py

from typing import Any

from django.db import models
from django.db.models.functions import TruncMonth
from django.http.request import HttpRequest
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.query import PageQuerySet

from website.common.models import BaseContentMixin, BasePage
from website.common.utils import TocEntry


class BlogListPage(BaseContentMixin, BasePage):  # type: ignore[misc]
    max_count = 1
    subpage_types = [
        "blog.BlogPostPage",
        "blog.BlogPostTagListPage",
        "blog.BlogCollectionListPage",
        "blog.BlogCollectionPage",
    ]
    content_panels = BasePage.content_panels + BaseContentMixin.content_panels

    @cached_property
    def reading_time(self) -> int:
        """
        How does one read a list page?
        """
        return 0

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

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

    def get_blog_posts(self) -> PageQuerySet:
        return BlogPostPage.objects.descendant_of(  # type:ignore[attr-defined]
            self
        ).live()

    def get_context(self, request: HttpRequest) -> dict:
        context = super().get_context(request)
        context["child_pages"] = (
            self.get_blog_posts()
            .select_related("hero_image")
            .select_related("hero_unsplash_photo")
            .prefetch_related("tags")
            .order_by("-date")
        )
        return context


class BlogPostPage(BaseContentMixin, BasePage):  # type: ignore[misc]
    subpage_types: list[Any] = []
    parent_page_types = [BlogListPage, "blog.BlogCollectionPage"]

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

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


class BlogPostTagListPage(BaseContentMixin, BasePage):  # type: ignore[misc]
    max_count = 1
    parent_page_types = [BlogListPage]
    subpage_types = ["blog.BlogPostTagPage"]

    content_panels = BasePage.content_panels + BaseContentMixin.content_panels

    @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")

    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(BaseContentMixin, BasePage):  # type: ignore[misc]
    subpage_types: list[Any] = []
    parent_page_types = [BlogPostTagListPage]

    content_panels = BasePage.content_panels + BaseContentMixin.content_panels

    @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 = (
            BlogListPage.objects.all().live().get()  # type:ignore[attr-defined]
        )
        return blog_list_page.get_blog_posts().filter(tags=self).order_by("-date")

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


class BlogCollectionListPage(BaseContentMixin, BasePage):  # type: ignore[misc]
    subpage_types: list[Any] = []
    parent_page_types = [BlogListPage]
    max_count = 1

    content_panels = BasePage.content_panels + BaseContentMixin.content_panels

    @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 = (
            BlogListPage.objects.all().live().get()  # type:ignore[attr-defined]
        )
        return BlogCollectionPage.objects.child_of(  # type:ignore[attr-defined]
            blog_list_page
        ).live()

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


class BlogCollectionPage(BaseContentMixin, BasePage):  # type: ignore[misc]
    parent_page_types = [BlogListPage]
    subpage_types = [BlogPostPage]

    content_panels = BasePage.content_panels + BaseContentMixin.content_panels

    @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(  # type:ignore[attr-defined]
            self
        ).order_by("-date")

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