[FastAPI] add /rss and /rss/modified

There are slight differences in that, with `python-feedgen`,
an empty description field completely omits the description,
but includes the description when there is one.

Signed-off-by: Kevin Morris <kevr@0cost.org>

aurweb/asgi.py

@@ -18,7 +18,7 @@ from aurweb.auth import BasicAuthBackend
 from aurweb.db import get_engine, query
 from aurweb.models.accepted_term import AcceptedTerm
 from aurweb.models.term import Term
-from aurweb.routers import accounts, auth, errors, html, sso, trusted_user
+from aurweb.routers import accounts, auth, errors, html, rss, sso, trusted_user
 
 # Setup the FastAPI app.
 app = FastAPI(exception_handlers=errors.exceptions)
@@ -50,6 +50,7 @@ async def app_startup():
     app.include_router(auth.router)
     app.include_router(accounts.router)
     app.include_router(trusted_user.router)
+    app.include_router(rss.router)
 
     # Initialize the database engine and ORM.
     get_engine()

aurweb/routers/rss.py

@@ -0,0 +1,84 @@
+from datetime import datetime
+
+from fastapi import APIRouter, Request
+from fastapi.responses import Response
+from feedgen.feed import FeedGenerator
+
+from aurweb import db, util
+from aurweb.models.package import Package
+from aurweb.models.package_base import PackageBase
+
+router = APIRouter()
+
+
+def make_rss_feed(request: Request, packages: list,
+                  date_attr: str):
+    """ Create an RSS Feed string for some packages.
+
+    :param request: A FastAPI request
+    :param packages: A list of packages to add to the RSS feed
+    :param date_attr: The date attribute (DB column) to use
+    :return: RSS Feed string
+    """
+
+    feed = FeedGenerator()
+    feed.title("AUR Newest Packages")
+    feed.description("The latest and greatest packages in the AUR")
+    base = f"{request.url.scheme}://{request.url.netloc}"
+    feed.link(href=base, rel="alternate")
+    feed.link(href=f"{base}/rss", rel="self")
+    feed.image(title="AUR Newest Packages",
+               url=f"{base}/css/archnavbar/aurlogo.png",
+               link=base,
+               description="AUR Newest Packages Feed")
+
+    for pkg in packages:
+        entry = feed.add_entry(order="append")
+        entry.title(pkg.Name)
+        entry.link(href=f"{base}/packages/{pkg.Name}", rel="alternate")
+        entry.link(href=f"{base}/rss", rel="self", type="application/rss+xml")
+        entry.description(pkg.Description or str())
+
+        attr = getattr(pkg.PackageBase, date_attr)
+        dt = util.timestamp_to_datetime(attr)
+        dt = util.as_timezone(dt, request.user.Timezone)
+        entry.pubDate(dt.strftime("%Y-%m-%d %H:%M:%S%z"))
+
+        entry.source(f"{base}")
+        if pkg.PackageBase.Maintainer:
+            entry.author(author={"name": pkg.PackageBase.Maintainer.Username})
+        entry.guid(f"{pkg.Name} - {attr}")
+
+    return feed.rss_str()
+
+
+@router.get("/rss/")
+async def rss(request: Request):
+    packages = db.query(Package).join(PackageBase).order_by(
+        PackageBase.SubmittedTS.desc()).limit(100)
+    feed = make_rss_feed(request, packages, "SubmittedTS")
+
+    response = Response(feed, media_type="application/rss+xml")
+    package = packages.first()
+    if package:
+        dt = datetime.utcfromtimestamp(package.PackageBase.SubmittedTS)
+        modified = dt.strftime("%a, %d %m %Y %H:%M:%S GMT")
+        response.headers["Last-Modified"] = modified
+
+    return response
+
+
+@router.get("/rss/modified")
+async def rss_modified(request: Request):
+    packages = db.query(Package).join(PackageBase).order_by(
+        PackageBase.ModifiedTS.desc()).limit(100)
+    feed = make_rss_feed(request, packages, "ModifiedTS")
+
+    response = Response(feed, media_type="application/rss+xml")
+    package = packages.first()
+    if package:
+        dt = datetime.utcfromtimestamp(package.PackageBase.ModifiedTS)
+        modified = dt.strftime("%a, %d %m %Y %H:%M:%S GMT")
+        response.headers["Last-Modified"] = modified
+
+    return response