feat: handle different distance strategy

vector_store.py

@@ -17,7 +17,7 @@ from model import Article
 from models.distance import DistanceStrategy
 from utils import str_to_list
 
-DEFAULT_DISTANCE_STRATEGY = DistanceStrategy.COSINE
+DEFAULT_DISTANCE_STRATEGY = DistanceStrategy.EUCLIDEAN
 
 _LANGCHAIN_DEFAULT_COLLECTION_NAME = "langchain"
 
@@ -200,13 +200,13 @@ class CustomVectorStore(VectorStore):
         return docs
 
     @property
-    def distance_strategy(self) -> Any:
+    def distance_strategy(self) -> str | None:
         if self._distance_strategy == DistanceStrategy.EUCLIDEAN:
-            return self.EmbeddingStore.embedding.l2_distance
+            return "<->"
         elif self._distance_strategy == DistanceStrategy.COSINE:
-            return self.EmbeddingStore.embedding.cosine_distance
+            return "<=>"
         elif self._distance_strategy == DistanceStrategy.MAX_INNER_PRODUCT:
-            return self.EmbeddingStore.embedding.max_inner_product
+            return "<#>"
         else:
             raise ValueError(
                 f"Got unexpected value for distance: {self._distance_strategy}. "
@@ -265,7 +265,7 @@ class CustomVectorStore(VectorStore):
                         a.abstract_en,
                         string_agg(distinct keyword."name", ',') as keywords, 
                         string_agg(distinct author."name", ',') as authors,
-                        abstract_embedding_en <-> '{str(embedding)}' as distance
+                        abstract_embedding_en {self.distance_strategy} '{str(embedding)}' as distance
                     from article a
                     left join article_keyword ON article_keyword.article_id = a.id 
                     left join keyword on article_keyword.keyword_id = keyword.id