added check function for user to post relationship

neo4jAPI/relationship.go

@@ -61,3 +61,26 @@ func UserToPostRelationship(ctx context.Context, driver neo4j.DriverWithContext,
 
 	return nil
 }
+
+// CheckUserToPostRelationship gives back a bool if the connection between the post and the user exists
+func CheckUserToPostRelationship(ctx context.Context, driver neo4j.DriverWithContext, e621PostID int64, e621UserID int64) (error, bool) {
+	query := `
+		MATCH (user:e621User {e621ID: $e621PostID})-[favorite:IS_FAVORITE]->(post:e621Post {e621PostID: $e621ID})
+		RETURN COUNT(favorite) > 0 AS isFavorite
+		`
+	params := map[string]interface{}{
+		"e621PostID": e621PostID,
+		"e621ID":     e621UserID,
+	}
+
+	result, err := neo4j.ExecuteQuery(ctx, driver, query, params, neo4j.EagerResultTransformer)
+	if err != nil {
+		return err, false
+	}
+
+	exists, _, err := neo4j.GetRecordValue[bool](result.Records[0], "isFavorite")
+	if err != nil {
+		return err, false
+	}
+	return nil, exists
+}