Add a /commitfests.ics feed

pgcommitfest/commitfest/feeds.py

@@ -1,5 +1,18 @@
+from __future__ import annotations
+
 from django.contrib.syndication.views import Feed
 
+from collections.abc import Iterable
+from datetime import timedelta
+from typing import TYPE_CHECKING
+
+from icalendar import Calendar, Event
+
+if TYPE_CHECKING:
+    from collections.abc import Iterable
+
+    from .models import CommitFest
+
 
 class ActivityFeed(Feed):
     title = description = "Commitfest Activity Log"
@@ -34,3 +47,31 @@ def item_link(self, item):
 
     def item_pubdate(self, item):
         return item["date"]
+
+
+def calendar(commitfests: Iterable[CommitFest]) -> Calendar:
+    """
+    Build an RFC 5545 iCalendar document with one all-day VEVENT per
+    commitfest, covering its start and end date.
+    """
+    calendar = Calendar.new(
+        prodid="-//PostgreSQL Commitfest//commitfest.postgresql.org//EN",
+        name="PostgreSQL Commitfests",
+        description="Start and end dates of PostgreSQL Commitfests",
+        method="PUBLISH",
+    )
+
+    for cf in commitfests:
+        event = Event.new(
+            uid=f"commitfest-{cf.name}@commitfest.postgresql.org",
+            summary=cf.title,
+            start=cf.startdate,
+            # DTEND is exclusive for all-day events, so add a day to make the
+            # last day of the commitfest show up as included on the calendar.
+            end=cf.enddate + timedelta(days=1),
+            description=f"Status: {cf.statusstring}",
+            url=f"https://commitfest.postgresql.org/{cf.id}/",
+        )
+        calendar.add_component(event)
+
+    return calendar

pgcommitfest/commitfest/templates/all_commitfests.html

@@ -1,10 +1,10 @@
 {%extends "base.html"%}
 {%block contents%}
+ <p><a href="/commitfests.ics">Subscribe to Commitfest dates (ICS)</a></p>
  <ul>
   {%for c in commitfests%}
    <li><a href="/{{c.id}}/">{{c}}</a> ({{c.statusstring}} - {{c.periodstring}})</li>
   {%endfor%}
  </ul>
  <br/>
 {%endblock%}
-

pgcommitfest/commitfest/templates/archive.html

@@ -1,9 +1,9 @@
 {%extends "base.html"%}
 {%block contents%}
+ <p><a href="/commitfests.ics">Subscribe to Commitfest dates (ICS)</a></p>
  <ul>
   {%for c in commitfests%}
    <li><a href="/{{c.id}}/">{{c}}</a> ({{c.statusstring}}{%if c.startdate%} - {{c.periodstring}}{%endif%})</li>
   {%endfor%}
  </ul>
 {%endblock%}
-

pgcommitfest/commitfest/tests/test_ics_feed.py

@@ -0,0 +1,57 @@
+"""
+Tests for the /commitfests.ics calendar feed.
+"""
+
+from __future__ import annotations
+
+from datetime import timedelta
+from typing import TYPE_CHECKING, cast
+
+import pytest
+from icalendar import Calendar, Event
+
+if TYPE_CHECKING:
+    from pgcommitfest.commitfest.models import CommitFest
+
+pytestmark = pytest.mark.django_db
+
+
+def _get_calendar(client) -> Calendar:
+    response = client.get("/commitfests.ics")
+    assert response.status_code == 200
+    assert response["Content-Type"] == "text/calendar; charset=utf-8"
+    return Calendar.from_ical(response.content)
+
+
+def _get_events(calendar: Calendar) -> list[Event]:
+    return cast("list[Event]", calendar.walk("VEVENT"))
+
+
+def test_commitfests_ics_empty(client):
+    """
+    With no commitfests, we still get a valid, empty calendar.
+    """
+    calendar = _get_calendar(client)
+
+    assert len(_get_events(calendar)) == 0
+
+
+def test_commitfests_ics_contains_all_commitfests(client, commitfests: dict[str, CommitFest]):
+    """
+    Every commitfest, regardless of status, shows up as a VEVENT with the right
+    dates, DTEND being the day after enddate (exclusive).
+    """
+    calendar = _get_calendar(client)
+
+    events = _get_events(calendar)
+    assert len(events) == len(commitfests)
+
+    events_by_uid = {cast("str", event.uid): event for event in events}
+
+    for cf in commitfests.values():
+        event = events_by_uid[f"commitfest-{cf.name}@commitfest.postgresql.org"]
+        assert event.summary == f"Commitfest {cf.name}"
+        assert event.url == f"https://commitfest.postgresql.org/{cf.pk}/"
+        assert event.description == f"Status: {cf.statusstring}"
+        assert event.start == cf.startdate
+        assert event.end == cf.enddate + timedelta(days=1)

pgcommitfest/commitfest/views.py

@@ -6,6 +6,7 @@
 from django.db.models import Count, Q
 from django.http import (
     Http404,
+    HttpRequest,
     HttpResponse,
     HttpResponseForbidden,
     HttpResponseRedirect,
@@ -27,7 +28,7 @@
 from pgcommitfest.userprofile.util import UserWrapper
 
 from .ajax import _archivesAPI, doAttachThread, refresh_single_thread
-from .feeds import ActivityFeed
+from .feeds import ActivityFeed, calendar
 from .forms import (
     BulkEmailForm,
     CommentForm,
@@ -195,6 +196,20 @@ def archive(request):
     )
 
 
+def commitfests_ics(_: HttpRequest) -> HttpResponse:
+    """
+    Calendar feed of all commitfests in iCalendar format (RFC 5545).
+    """
+    commitfests = CommitFest.objects.order_by("startdate")
+
+    response = HttpResponse(
+        calendar(commitfests).to_ical(),
+        content_type="text/calendar; charset=utf-8"
+    )
+    response["Content-Disposition"] = 'inline; filename="commitfests.ics"'
+    return response
+
+
 def activity(request, cfid=None, rss=None):
     # Number of notes to fetch
     if rss:

pgcommitfest/urls.py

@@ -24,6 +24,7 @@
     re_path(r"^commitfest_history/$", views.commitfest_history),
     re_path(r"^me/$", views.me_legacy_redirect),
     re_path(r"^archive/$", views.archive),
+    re_path(r"^commitfests\.ics$", views.commitfests_ics),
     re_path(r"^activity(?P<rss>\.rss)?/", views.activity),
     re_path(r"^(\d+)/$", views.commitfest),
     re_path(r"^(open|inprogress|current|draft)/(.*)$", views.redir),

pyproject.toml

@@ -6,6 +6,7 @@ readme = "README.md"
 license = "PostgreSQL"
 dependencies = [
     "django>=5.2,<6.0",
+    "icalendar",
     "psycopg2",
     "simplejson",
     "requests",