[i18n] Add /i18n endpoint to provide all custom node translations (#6558)

* [i18n] Add /i18n endpoint to provide all custom node translations

* Sort glob result for deterministic ordering

* Update comment

app/custom_node_manager.py

@@ -4,12 +4,93 @@ import os
 import folder_paths
 import glob
 from aiohttp import web
+import json
+import logging
+from functools import lru_cache
+
+from utils.json_util import merge_json_recursive
+
+
+# Extra locale files to load into main.json
+EXTRA_LOCALE_FILES = [
+    "nodeDefs.json",
+    "commands.json",
+    "settings.json",
+]
+
+
+def safe_load_json_file(file_path: str) -> dict:
+    if not os.path.exists(file_path):
+        return {}
+
+    try:
+        with open(file_path, "r", encoding="utf-8") as f:
+            return json.load(f)
+    except json.JSONDecodeError:
+        logging.error(f"Error loading {file_path}")
+        return {}
+
 
 class CustomNodeManager:
-    """
-    Placeholder to refactor the custom node management features from ComfyUI-Manager.
-    Currently it only contains the custom workflow templates feature.
-    """
+    @lru_cache(maxsize=1)
+    def build_translations(self):
+        """Load all custom nodes translations during initialization. Translations are
+        expected to be loaded from `locales/` folder.
+
+        The folder structure is expected to be the following:
+        - custom_nodes/
+            - custom_node_1/
+                - locales/
+                    - en/
+                        - main.json
+                        - commands.json
+                        - settings.json
+
+        returned translations are expected to be in the following format:
+        {
+            "en": {
+                "nodeDefs": {...},
+                "commands": {...},
+                "settings": {...},
+                ...{other main.json keys}
+            }
+        }
+        """
+
+        translations = {}
+
+        for folder in folder_paths.get_folder_paths("custom_nodes"):
+            # Sort glob results for deterministic ordering
+            for custom_node_dir in sorted(glob.glob(os.path.join(folder, "*/"))):
+                locales_dir = os.path.join(custom_node_dir, "locales")
+                if not os.path.exists(locales_dir):
+                    continue
+
+                for lang_dir in glob.glob(os.path.join(locales_dir, "*/")):
+                    lang_code = os.path.basename(os.path.dirname(lang_dir))
+
+                    if lang_code not in translations:
+                        translations[lang_code] = {}
+
+                    # Load main.json
+                    main_file = os.path.join(lang_dir, "main.json")
+                    node_translations = safe_load_json_file(main_file)
+
+                    # Load extra locale files
+                    for extra_file in EXTRA_LOCALE_FILES:
+                        extra_file_path = os.path.join(lang_dir, extra_file)
+                        key = extra_file.split(".")[0]
+                        json_data = safe_load_json_file(extra_file_path)
+                        if json_data:
+                            node_translations[key] = json_data
+
+                    if node_translations:
+                        translations[lang_code] = merge_json_recursive(
+                            translations[lang_code], node_translations
+                        )
+
+        return translations
+
     def add_routes(self, routes, webapp, loadedModules):
 
         @routes.get("/workflow_templates")
@@ -18,17 +99,36 @@ class CustomNodeManager:
             files = [
                 file
                 for folder in folder_paths.get_folder_paths("custom_nodes")
-                for file in glob.glob(os.path.join(folder, '*/example_workflows/*.json'))
+                for file in glob.glob(
+                    os.path.join(folder, "*/example_workflows/*.json")
+                )
             ]
-            workflow_templates_dict = {} # custom_nodes folder name -> example workflow names
+            workflow_templates_dict = (
+                {}
+            )  # custom_nodes folder name -> example workflow names
             for file in files:
-                custom_nodes_name = os.path.basename(os.path.dirname(os.path.dirname(file)))
+                custom_nodes_name = os.path.basename(
+                    os.path.dirname(os.path.dirname(file))
+                )
                 workflow_name = os.path.splitext(os.path.basename(file))[0]
-                workflow_templates_dict.setdefault(custom_nodes_name, []).append(workflow_name)
+                workflow_templates_dict.setdefault(custom_nodes_name, []).append(
+                    workflow_name
+                )
             return web.json_response(workflow_templates_dict)
 
         # Serve workflow templates from custom nodes.
         for module_name, module_dir in loadedModules:
-            workflows_dir = os.path.join(module_dir, 'example_workflows')
+            workflows_dir = os.path.join(module_dir, "example_workflows")
             if os.path.exists(workflows_dir):
-                webapp.add_routes([web.static('/api/workflow_templates/' + module_name, workflows_dir)])
+                webapp.add_routes(
+                    [
+                        web.static(
+                            "/api/workflow_templates/" + module_name, workflows_dir
+                        )
+                    ]
+                )
+
+        @routes.get("/i18n")
+        async def get_i18n(request):
+            """Returns translations from all custom nodes' locales folders."""
+            return web.json_response(self.build_translations())