Fall back to OMDb demo on rate limits

tools/content/imdb.py

@@ -1,6 +1,7 @@
 import json
 import os
 import re
+import urllib.error
 import urllib.parse
 import urllib.request
 
@@ -8,6 +9,9 @@ from jsonfile import PROJECT_ROOT
 
 IMDB_ID_PATTERN = re.compile(r"tt\d{7,9}")
 ENV_FILE = PROJECT_ROOT / ".env"
+OMDB_URL = "https://www.omdbapi.com/"
+OMDB_DEMO_URL = "http://www.omdbapi.com/demo.aspx/"
+RATE_LIMITED_STATUS = 401
 
 
 def imdb_id(text: str) -> str | None:
@@ -31,14 +35,22 @@ def omdb_api_key() -> str | None:
     return None
 
 
+def request_json(url: str, parameters: dict) -> dict:
+    with urllib.request.urlopen(f"{url}?{urllib.parse.urlencode(parameters)}", timeout=10) as response:
+        return json.load(response)
+
+
 def lookup(identifier: str) -> dict | None:
     api_key = omdb_api_key()
     if not api_key:
         return None
-    query = urllib.parse.urlencode({"apikey": api_key, "i": identifier})
     try:
-        with urllib.request.urlopen(f"https://www.omdbapi.com/?{query}", timeout=10) as response:
-            result = json.load(response)
+        try:
+            result = request_json(OMDB_URL, {"apikey": api_key, "i": identifier})
+        except urllib.error.HTTPError as error:
+            if error.code != RATE_LIMITED_STATUS:
+                raise
+            result = request_json(OMDB_DEMO_URL, {"i": identifier, "token": "demo"})
     except (OSError, ValueError):
         return None
     return result if result.get("Response") == "True" else None