From c987d336493edf888e47c61907ac80b36f99a032 Mon Sep 17 00:00:00 2001
From: Yongteng Lei <yongtengrey@outlook.com>
Date: Wed, 24 Dec 2025 09:32:55 +0800
Subject: [PATCH] Feat: deduplicate metadata lists during updates (#12125)

### What problem does this PR solve?

Deduplicate metadata lists during updates.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)
---
 api/db/services/document_service.py |  8 ++++++--
 common/metadata_utils.py            | 17 ++++++++++++++++-
 2 files changed, 22 insertions(+), 3 deletions(-)

diff --git a/api/db/services/document_service.py b/api/db/services/document_service.py
index 2f9e143f9..81bd160e3 100644
--- a/api/db/services/document_service.py
+++ b/api/db/services/document_service.py
@@ -33,6 +33,7 @@ from api.db.db_models import DB, Document, Knowledgebase, Task, Tenant, UserTena
 from api.db.db_utils import bulk_insert_into_db
 from api.db.services.common_service import CommonService
 from api.db.services.knowledgebase_service import KnowledgebaseService
+from common.metadata_utils import dedupe_list
 from common.misc_utils import get_uuid
 from common.time_utils import current_timestamp, get_format_time
 from common.constants import LLMType, ParserType, StatusEnum, TaskStatus, SVR_CONSUMER_GROUP_NAME
@@ -799,7 +800,10 @@ class DocumentService(CommonService):
                 match_provided = "match" in upd
                 if isinstance(meta[key], list):
                     if not match_provided:
-                        meta[key] = new_value
+                        if isinstance(new_value, list):
+                            meta[key] = dedupe_list(new_value)
+                        else:
+                            meta[key] = new_value
                         changed = True
                     else:
                         match_value = upd.get("match")
@@ -812,7 +816,7 @@ class DocumentService(CommonService):
                             else:
                                 new_list.append(item)
                         if replaced:
-                            meta[key] = new_list
+                            meta[key] = dedupe_list(new_list)
                             changed = True
                 else:
                     if not match_provided:
diff --git a/common/metadata_utils.py b/common/metadata_utils.py
index 4d4cceb4a..d7bb3c818 100644
--- a/common/metadata_utils.py
+++ b/common/metadata_utils.py
@@ -151,6 +151,18 @@ async def apply_meta_data_filter(
     return doc_ids
 
 
+def dedupe_list(values: list) -> list:
+    seen = set()
+    deduped = []
+    for item in values:
+        key = str(item)
+        if key in seen:
+            continue
+        seen.add(key)
+        deduped.append(item)
+    return deduped
+
+
 def update_metadata_to(metadata, meta):
     if not meta:
         return metadata
@@ -162,11 +174,13 @@ def update_metadata_to(metadata, meta):
             return metadata
     if not isinstance(meta, dict):
         return metadata
+
     for k, v in meta.items():
         if isinstance(v, list):
             v = [vv for vv in v if isinstance(vv, str)]
             if not v:
                 continue
+            v = dedupe_list(v)
         if not isinstance(v, list) and not isinstance(v, str):
             continue
         if k not in metadata:
@@ -177,6 +191,7 @@ def update_metadata_to(metadata, meta):
                 metadata[k].extend(v)
             else:
                 metadata[k].append(v)
+            metadata[k] = dedupe_list(metadata[k])
         else:
             metadata[k] = v
 
@@ -208,4 +223,4 @@ def metadata_schema(metadata: list|None) -> Dict[str, Any]:
     }
 
     json_schema["additionalProperties"] = False
-    return json_schema
\ No newline at end of file
+    return json_schema