initial draft of neo4j database driver

pkg/database/factory.go

@@ -7,7 +7,7 @@ import (
 )
 
 // NewDatabase creates a database instance based on the specified type.
-// Supported types: "badger", "dgraph"
+// Supported types: "badger", "dgraph", "neo4j"
 func NewDatabase(
 	ctx context.Context,
 	cancel context.CancelFunc,
@@ -23,8 +23,12 @@ func NewDatabase(
 		// Use the new dgraph implementation
 		// Import dynamically to avoid import cycles
 		return newDgraphDatabase(ctx, cancel, dataDir, logLevel)
+	case "neo4j":
+		// Use the new neo4j implementation
+		// Import dynamically to avoid import cycles
+		return newNeo4jDatabase(ctx, cancel, dataDir, logLevel)
 	default:
-		return nil, fmt.Errorf("unsupported database type: %s (supported: badger, dgraph)", dbType)
+		return nil, fmt.Errorf("unsupported database type: %s (supported: badger, dgraph, neo4j)", dbType)
 	}
 }
 
@@ -37,3 +41,13 @@ var newDgraphDatabase func(context.Context, context.CancelFunc, string, string)
 func RegisterDgraphFactory(factory func(context.Context, context.CancelFunc, string, string) (Database, error)) {
 	newDgraphDatabase = factory
 }
+
+// newNeo4jDatabase creates a neo4j database instance
+// This is defined here to avoid import cycles
+var newNeo4jDatabase func(context.Context, context.CancelFunc, string, string) (Database, error)
+
+// RegisterNeo4jFactory registers the neo4j database factory
+// This is called from the neo4j package's init() function
+func RegisterNeo4jFactory(factory func(context.Context, context.CancelFunc, string, string) (Database, error)) {
+	newNeo4jDatabase = factory
+}