Handle VATUSA outages on login

apps/vatsim/oauth.py

@@ -1,4 +1,5 @@
 import os
+from typing import Optional
 
 import requests
 from django.conf import settings
@@ -34,13 +35,6 @@ def process_oauth(code: str) -> User:
         .get("data")
     )
 
-    # Get user's home division. If they are in VATUSA get their home facility.
-    division = f"VAT{data.get('vatsim').get('division').get('id')}"
-    if division == "VATUSA":
-        req = requests.get(f"https://api.vatusa.net/v2/user/{data.get('cid')}")
-        if req.status_code == 200:
-            division = req.json().get("data").get("facility")
-
     user_query = User.objects.filter(cid=data.get("cid"))
     if not user_query.exists():
         user = User.objects.create_user(
@@ -49,15 +43,38 @@ def process_oauth(code: str) -> User:
             first_name=data.get("personal").get("name_first"),
             last_name=data.get("personal").get("name_last"),
             rating=data.get("vatsim").get("rating").get("short"),
-            home_facility=division,
+            home_facility=get_home_facility(
+                data.get("cid"),
+                data.get('vatsim').get('division').get('id'),
+            ),
         )
     else:
         user = user_query.first()
-        user.home_facility = division
+        user.home_facility = get_home_facility(
+            user.cid,
+            data.get('vatsim').get('division').get('id'),
+            user.home_facility,
+        )
         user.rating = data.get("vatsim").get("rating").get("short")
         user.save()
 
-    if division == "ZHU":
+    if user.home_facility == "ZHU":
         user.set_membership("HC")
 
     return user
+
+# Get the user's home facility.
+# Fallback to existing facility if VATUSA API is down.
+def get_home_facility(cid: int, division: str, existing_facility: Optional[str] = None) -> str:
+    if division != "USA":
+        return f"VAT{division}"
+
+    req = requests.get(f"https://api.vatusa.net/v2/user/{cid}")
+
+    if req.status_code == 404:
+        return "VATUSA"
+
+    if req.status_code != 200:
+        return existing_facility or "VATUSA"
+
+    return req.json().get("data").get("facility")