fix: stable event hashing, HEAD fallback, caldav str/bytes compat

sync_calendar.py

@@ -56,9 +56,14 @@ def sync_once(state: SyncState, health: HealthServer, config: Config) -> bool:
     logger.info("Starting sync cycle...")
 
     try:
-        r = requests.head(config.ics_url, headers=HEADERS, timeout=30, allow_redirects=True)
-        r.raise_for_status()
-        remote_etag = r.headers.get("ETag")
+        remote_etag = None
+        try:
+            r = requests.head(config.ics_url, headers=HEADERS, timeout=15, allow_redirects=True)
+            if r.status_code < 400:
+                remote_etag = r.headers.get("ETag")
+        except Exception:
+            pass
+
         cached_hash, cached_etag, _ = state.get_ics_cache()
 
         if remote_etag and cached_etag == remote_etag:
@@ -91,6 +96,8 @@ def sync_once(state: SyncState, health: HealthServer, config: Config) -> bool:
         to_update = deltas["to_update"]
         to_delete = deltas["to_delete"]
 
+        is_first_run = not state.get_event_uids() and not cached_hash
+
         if not to_add and not to_update and not to_delete:
             logger.info("Calendar is already in sync.")
             duration = time.time() - start_time
@@ -100,6 +107,24 @@ def sync_once(state: SyncState, health: HealthServer, config: Config) -> bool:
                 True,
                 len(ics_uids),
             )
+            for uid, h in ics_uids.items():
+                state.upsert_event(uid, h)
+            return True
+
+        if is_first_run and not to_delete:
+            logger.info(
+                "First run detected: %d events in ICS. Registering state without re-adding to calendar.",
+                len(to_add),
+            )
+            for uid, h in ics_uids.items():
+                state.upsert_event(uid, h)
+            duration = time.time() - start_time
+            health.update_status(
+                datetime.now(timezone.utc),
+                duration,
+                True,
+                len(ics_uids),
+            )
             return True
 
         logger.info(