feat: master feed card (#15)

* feat: master feed card

* fix: adjust tests

backend/app/services/feed_generator.py

@@ -3,7 +3,7 @@ from feedgen.feed import FeedGenerator
 from sqlalchemy.orm import Session
 
 from app.core.config import settings
-from app.crud.entries import get_entries_by_newsletter
+from app.crud.entries import get_all_entries, get_entries_by_newsletter
 from app.crud.newsletters import get_newsletter_by_identifier
 
 
@@ -41,3 +41,34 @@ def generate_feed(db: Session, feed_identifier: str):
             fe.published(entry.received_at)
 
     return fg.atom_str(pretty=True)
+
+
+def generate_master_feed(db: Session):
+    """Generate a master Atom feed for all newsletters."""
+    entries = get_all_entries(db)
+
+    feed_url = f"{settings.app_base_url}/feeds/all"
+    logo_url = f"{settings.app_base_url}/logo.png"
+    icon_url = f"{settings.app_base_url}/favicon.ico"
+
+    fg = FeedGenerator()
+    fg.id("urn:letterfeed:master")
+    fg.title("LetterFeed: All Newsletters")
+    fg.logo(logo_url)
+    fg.icon(icon_url)
+    fg.link(href=feed_url, rel="self")
+    fg.link(href=f"{settings.app_base_url}/", rel="alternate")
+    fg.description("A master feed of all your newsletters.")
+
+    for entry in entries:
+        fe = fg.add_entry()
+        fe.id(f"urn:letterfeed:entry:{entry.id}")
+        fe.title(f"[{entry.newsletter.name}] {entry.subject}")
+        fe.content(entry.body, type="html")
+        if entry.received_at.tzinfo is None:
+            timezone_aware_received_at = entry.received_at.replace(tzinfo=tz.tzutc())
+            fe.published(timezone_aware_received_at)
+        else:
+            fe.published(entry.received_at)
+
+    return fg.atom_str(pretty=True)