From 546128fd2301eb63a3582d51956d314ed8f2fa5d Mon Sep 17 00:00:00 2001
From: Simon <simobilleter@gmail.com>
Date: Mon, 26 Jan 2026 18:15:05 +0700
Subject: [PATCH] fix nested dict merging for ytobs

---
 backend/common/src/helper.py        | 13 +++++++++++++
 backend/download/src/yt_dlp_base.py | 13 ++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/backend/common/src/helper.py b/backend/common/src/helper.py
index a29da9a2..0bb43aca 100644
--- a/backend/common/src/helper.py
+++ b/backend/common/src/helper.py
@@ -133,6 +133,19 @@ def time_parser(timestamp: str) -> float:
     return int(hours) * 60 * 60 + int(minutes) * 60 + float(seconds)
 
 
+def deep_merge(target: dict, source: dict) -> None:
+    """inplace nested dict merge, recursive"""
+    for key, value in source.items():
+        if (
+            key in target
+            and isinstance(target[key], dict)
+            and isinstance(value, dict)
+        ):
+            deep_merge(target[key], value)
+        else:
+            target[key] = value
+
+
 def clear_dl_cache(cache_dir: str) -> int:
     """clear leftover files from dl cache"""
     print("clear download cache")
diff --git a/backend/download/src/yt_dlp_base.py b/backend/download/src/yt_dlp_base.py
index 9fc0be6a..212401d2 100644
--- a/backend/download/src/yt_dlp_base.py
+++ b/backend/download/src/yt_dlp_base.py
@@ -12,6 +12,7 @@ from os import path
 import yt_dlp
 from appsettings.src.config import AppConfig
 from common.src.env_settings import EnvironmentSettings
+from common.src.helper import deep_merge
 from common.src.ta_redis import RedisArchivist
 from django.conf import settings
 
@@ -38,7 +39,7 @@ class YtWrap:
     def build_obs(self):
         """build yt-dlp obs"""
         self.obs = self.OBS_BASE.copy()
-        self.obs.update(self.obs_request)
+        deep_merge(self.obs, self.obs_request)
         if self.config:
             self._add_cookie()
             self._add_potoken()
@@ -61,7 +62,8 @@ class YtWrap:
         """add potoken if enabled"""
         if self.config["downloads"].get("potoken"):
             potoken = POTokenHandler(self.config).get()
-            self.obs.update(
+            deep_merge(
+                self.obs,
                 {
                     "extractor_args": {
                         "youtube": {
@@ -69,7 +71,7 @@ class YtWrap:
                             "player-client": ["mweb", "default"],
                         },
                     }
-                }
+                },
             )
 
     def _add_potoken_url(self):
@@ -77,14 +79,15 @@ class YtWrap:
         if pot_provider_url := self.config["downloads"].get(
             "pot_provider_url"
         ):
-            self.obs.update(
+            deep_merge(
+                self.obs,
                 {
                     "extractor_args": {
                         "youtubepot-bgutilhttp": {
                             "base_url": [pot_provider_url]
                         }
                     }
-                }
+                },
             )
 
     def download(self, url):