From 61e47c0b2f1a1b5b0013e17707d6b2220862ff8f Mon Sep 17 00:00:00 2001
From: hajdul88 <52442977+hajdul88@users.noreply.github.com>
Date: Mon, 27 Oct 2025 13:39:02 +0100
Subject: [PATCH] feat: adds multifile ontology handling to OntologyResolver

---
 .../ontology/get_default_ontology_resolver.py | 10 ++++-
 .../rdf_xml/RDFLibOntologyResolver.py         | 42 +++++++++++++++----
 2 files changed, 41 insertions(+), 11 deletions(-)

diff --git a/cognee/modules/ontology/get_default_ontology_resolver.py b/cognee/modules/ontology/get_default_ontology_resolver.py
index f9aebe59a..6857c339b 100644
--- a/cognee/modules/ontology/get_default_ontology_resolver.py
+++ b/cognee/modules/ontology/get_default_ontology_resolver.py
@@ -21,7 +21,8 @@ def get_ontology_resolver_from_env(
             Supported value: "rdflib".
         matching_strategy (str): The matching strategy to apply.
             Supported value: "fuzzy".
-        ontology_file_path (str): Path to the ontology file required for the resolver.
+        ontology_file_path (str): Path to the ontology file(s) required for the resolver.
+            Can be a single path or comma-separated paths for multiple files.
 
     Returns:
         BaseOntologyResolver: An instance of the requested ontology resolver.
@@ -31,8 +32,13 @@ def get_ontology_resolver_from_env(
             or if required parameters are missing.
     """
     if ontology_resolver == "rdflib" and matching_strategy == "fuzzy" and ontology_file_path:
+        if "," in ontology_file_path:
+            file_paths = [path.strip() for path in ontology_file_path.split(",")]
+        else:
+            file_paths = ontology_file_path
+        
         return RDFLibOntologyResolver(
-            matching_strategy=FuzzyMatchingStrategy(), ontology_file=ontology_file_path
+            matching_strategy=FuzzyMatchingStrategy(), ontology_file=file_paths
         )
     else:
         raise EnvironmentError(
diff --git a/cognee/modules/ontology/rdf_xml/RDFLibOntologyResolver.py b/cognee/modules/ontology/rdf_xml/RDFLibOntologyResolver.py
index 2a7a03751..657ebb667 100644
--- a/cognee/modules/ontology/rdf_xml/RDFLibOntologyResolver.py
+++ b/cognee/modules/ontology/rdf_xml/RDFLibOntologyResolver.py
@@ -2,7 +2,7 @@ import os
 import difflib
 from cognee.shared.logging_utils import get_logger
 from collections import deque
-from typing import List, Tuple, Dict, Optional, Any
+from typing import List, Tuple, Dict, Optional, Any, Union
 from rdflib import Graph, URIRef, RDF, RDFS, OWL
 
 from cognee.modules.ontology.exceptions import (
@@ -26,22 +26,46 @@ class RDFLibOntologyResolver(BaseOntologyResolver):
 
     def __init__(
         self,
-        ontology_file: Optional[str] = None,
+        ontology_file: Optional[Union[str, List[str]]] = None,
         matching_strategy: Optional[MatchingStrategy] = None,
     ) -> None:
         super().__init__(matching_strategy)
         self.ontology_file = ontology_file
         try:
-            if ontology_file and os.path.exists(ontology_file):
+            # Convert single file to list for uniform processing
+            files_to_load = []
+            if ontology_file is not None:
+                if isinstance(ontology_file, str):
+                    files_to_load = [ontology_file]
+                elif isinstance(ontology_file, list):
+                    files_to_load = ontology_file
+                else:
+                    raise ValueError(f"ontology_file must be a string, list of strings, or None. Got: {type(ontology_file)}")
+            
+            # Load ontology files into a single graph
+            if files_to_load:
                 self.graph = Graph()
-                self.graph.parse(ontology_file)
-                logger.info("Ontology loaded successfully from file: %s", ontology_file)
+                loaded_files = []
+                for file_path in files_to_load:
+                    if os.path.exists(file_path):
+                        self.graph.parse(file_path)
+                        loaded_files.append(file_path)
+                        logger.info("Ontology loaded successfully from file: %s", file_path)
+                    else:
+                        logger.warning(
+                            "Ontology file '%s' not found. Skipping this file.",
+                            file_path,
+                        )
+                
+                if not loaded_files:
+                    logger.info("No valid ontology files found. No owl ontology will be attached to the graph.")
+                    self.graph = None
+                else:
+                    logger.info("Total ontology files loaded: %d", len(loaded_files))
             else:
-                logger.info(
-                    "Ontology file '%s' not found. No owl ontology will be attached to the graph.",
-                    ontology_file,
-                )
+                logger.info("No ontology file provided. No owl ontology will be attached to the graph.")
                 self.graph = None
+            
             self.build_lookup()
         except Exception as e:
             logger.error("Failed to load ontology", exc_info=e)