Revert "Update reciprocal_rank_stage"

This reverts commit fc2e381.

Author: aclark4life

libs/langchain-mongodb/langchain_mongodb/pipelines.py

@@ -12,7 +12,6 @@
 from pymongo_search_utils import (
     combine_pipelines,  # noqa: F401
     final_hybrid_stage,  # noqa: F401
-    reciprocal_rank_stage,  # noqa: F401
 )
 
 
@@ -95,3 +94,41 @@ def vector_search_stage(
     if filter:
         stage["filter"] = filter
     return {"$vectorSearch": stage}
+
+
+def reciprocal_rank_stage(
+    score_field: str, penalty: float = 0, weight: float = 1, **kwargs: Any
+) -> List[Dict[str, Any]]:
+    """
+    Stage adds Weighted Reciprocal Rank Fusion (WRRF) scoring.
+
+    First, it groups documents into an array, assigns rank by array index,
+    and then computes a weighted RRF score.
+
+    Args:
+        score_field: A unique string to identify the search being ranked.
+        penalty: A non-negative float (e.g., 60 for RRF-60). Controls the denominator.
+        weight: A float multiplier for this source's importance.
+        **kwargs: Ignored; allows future extensions or passthrough args.
+
+    Returns:
+        Aggregation pipeline stage for weighted RRF scoring.
+    """
+
+    return [
+        {"$group": {"_id": None, "docs": {"$push": "$$ROOT"}}},
+        {"$unwind": {"path": "$docs", "includeArrayIndex": "rank"}},
+        {
+            "$addFields": {
+                f"docs.{score_field}": {
+                    "$multiply": [
+                        weight,
+                        {"$divide": [1.0, {"$add": ["$rank", penalty, 1]}]},
+                    ]
+                },
+                "docs.rank": "$rank",
+                "_id": "$docs._id",
+            }
+        },
+        {"$replaceRoot": {"newRoot": "$docs"}},
+    ]

libs/langchain-mongodb/pyproject.toml

@@ -42,7 +42,7 @@ dev = [
     "langchain-tests==0.3.22,<1.0",
     "pip>=25.0.1",
     "typing-extensions>=4.12.2",
-    "pymongo-search-utils@git+https://github.com/aclark4life/pymongo-search-utils.git@INTPYTHON-752",
+    "pymongo-search-utils@git+https://github.com/mongodb-labs/pymongo-search-utils.git",
 ]
 
 [tool.pytest.ini_options]