Update app.py

app.py

@@ -19,7 +19,14 @@ def download_video():
     try:
         # YouTube URLを作成
         youtube_url = f'https://www.youtube.com/watch?v={video_id}'
-        yt = YouTube(youtube_url, use_oauth=True, allow_oauth_cache=True)
+        
+        # OAuthを有効化してYouTubeオブジェクトを作成
+        try:
+            yt = YouTube(youtube_url, use_oauth=True, allow_oauth_cache=True)
+        except Exception as e:
+            if "device" in str(e).lower():
+                return jsonify({'error': 'OAuth authentication required. Please follow the instructions in the log to complete authentication.'}), 401
+            return jsonify({'error': str(e)}), 500
 
         # ファイル保存用ディレクトリ
         download_dir = "downloads"