feat: set default database name based on provider (#1026)

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## Description
Default graph name will consider provider when being created

## DCO Affirmation
I affirm that all code in every commit of this pull request conforms to
the terms of the Topoteretes Developer Certificate of Origin.

cognee/infrastructure/databases/graph/config.py

@@ -3,6 +3,8 @@
 import os
 from functools import lru_cache
 from pydantic_settings import BaseSettings, SettingsConfigDict
+import pydantic
+from pydantic import Field
 from cognee.shared.data_models import KnowledgeGraph
 from cognee.root_dir import get_absolute_path
 
@@ -29,18 +31,33 @@ class GraphConfig(BaseSettings):
     - model_config
     """
 
-    graph_filename: str = "cognee_graph"
+    # Using Field we are able to dynamically load current GRAPH_DATABASE_PROVIDER value in the model validator part
-    graph_database_provider: str = "kuzu"
+    # and determine default graph db file and path based on this parameter if no values are provided
+    graph_database_provider: str = Field("kuzu", env="GRAPH_DATABASE_PROVIDER")
+
     graph_database_url: str = ""
     graph_database_username: str = ""
     graph_database_password: str = ""
     graph_database_port: int = 123
-    graph_file_path: str = os.path.join(
+    graph_file_path: str = ""
-        os.path.join(get_absolute_path(".cognee_system"), "databases"), graph_filename
+    graph_filename: str = ""
-    )
     graph_model: object = KnowledgeGraph
     graph_topology: object = KnowledgeGraph
-    model_config = SettingsConfigDict(env_file=".env", extra="allow")
+    model_config = SettingsConfigDict(env_file=".env", extra="allow", populate_by_name=True)
+
+    # Model validator updates graph_filename and path dynamically after class creation based on current database provider
+    # If no specific graph_filename or path are provided
+    @pydantic.model_validator(mode="after")
+    def fill_derived(cls, values):
+        provider = values.graph_database_provider.lower()
+        # Set filename based on graph database provider if no filename is provided
+        if not values.graph_filename:
+            values.graph_filename = f"cognee_graph_{provider}"
+        # Set file path based on graph database provider if no file path is provided
+        if not values.graph_file_path:
+            base = os.path.join(get_absolute_path(".cognee_system"), "databases")
+            values.graph_file_path = os.path.join(base, values.graph_filename)
+        return values
 
     def to_dict(self) -> dict:
         """

cognee/infrastructure/databases/graph/kuzu/adapter.py

@@ -46,11 +46,7 @@ class KuzuAdapter(GraphDBInterface):
     def _initialize_connection(self) -> None:
         """Initialize the Kuzu database connection and schema."""
         try:
-            try:
+            os.makedirs(self.db_path, exist_ok=True)
-                os.makedirs(self.db_path, exist_ok=True)
-            except FileExistsError:
-                os.remove(self.db_path)
-                os.makedirs(self.db_path, exist_ok=True)
 
             self.db = Database(self.db_path)
             self.db.init_database()
@@ -79,7 +75,7 @@ class KuzuAdapter(GraphDBInterface):
             logger.debug("Kuzu database initialized successfully")
         except Exception as e:
             logger.error(f"Failed to initialize Kuzu database: {e}")
-            raise
+            raise e
 
     async def query(self, query: str, params: Optional[dict] = None) -> List[Tuple]:
         """