added dynamic model list

app/model_loader.py

@@ -0,0 +1,92 @@
+import httpx
+import asyncio
+import json
+from typing import List, Dict, Optional, Any
+
+# Assuming config.py is in the same directory level for Docker execution
+import config as app_config 
+
+_model_cache: Optional[Dict[str, List[str]]] = None
+_cache_lock = asyncio.Lock()
+
+async def fetch_and_parse_models_config() -> Optional[Dict[str, List[str]]]:
+    """
+    Fetches the model configuration JSON from the URL specified in app_config.
+    Parses it and returns a dictionary with 'vertex_models' and 'vertex_express_models'.
+    Returns None if fetching or parsing fails.
+    """
+    if not app_config.MODELS_CONFIG_URL:
+        print("ERROR: MODELS_CONFIG_URL is not set in the environment/config.")
+        return None
+
+    print(f"Fetching model configuration from: {app_config.MODELS_CONFIG_URL}")
+    try:
+        async with httpx.AsyncClient() as client:
+            response = await client.get(app_config.MODELS_CONFIG_URL)
+            response.raise_for_status() # Raise an exception for HTTP errors (4xx or 5xx)
+            data = response.json()
+            
+            # Basic validation of the fetched data structure
+            if isinstance(data, dict) and \
+               "vertex_models" in data and isinstance(data["vertex_models"], list) and \
+               "vertex_express_models" in data and isinstance(data["vertex_express_models"], list):
+                print("Successfully fetched and parsed model configuration.")
+                return {
+                    "vertex_models": data["vertex_models"],
+                    "vertex_express_models": data["vertex_express_models"]
+                }
+            else:
+                print(f"ERROR: Fetched model configuration has an invalid structure: {data}")
+                return None
+    except httpx.RequestError as e:
+        print(f"ERROR: HTTP request failed while fetching model configuration: {e}")
+        return None
+    except json.JSONDecodeError as e:
+        print(f"ERROR: Failed to decode JSON from model configuration: {e}")
+        return None
+    except Exception as e:
+        print(f"ERROR: An unexpected error occurred while fetching/parsing model configuration: {e}")
+        return None
+
+async def get_models_config() -> Dict[str, List[str]]:
+    """
+    Returns the cached model configuration.
+    If not cached, fetches and caches it.
+    Returns a default empty structure if fetching fails.
+    """
+    global _model_cache
+    async with _cache_lock:
+        if _model_cache is None:
+            print("Model cache is empty. Fetching configuration...")
+            _model_cache = await fetch_and_parse_models_config()
+            if _model_cache is None: # If fetching failed, use a default empty structure
+                print("WARNING: Using default empty model configuration due to fetch/parse failure.")
+                _model_cache = {"vertex_models": [], "vertex_express_models": []}
+    return _model_cache
+
+async def get_vertex_models() -> List[str]:
+    config = await get_models_config()
+    return config.get("vertex_models", [])
+
+async def get_vertex_express_models() -> List[str]:
+    config = await get_models_config()
+    return config.get("vertex_express_models", [])
+
+async def refresh_models_config_cache() -> bool:
+    """
+    Forces a refresh of the model configuration cache.
+    Returns True if successful, False otherwise.
+    """
+    global _model_cache
+    print("Attempting to refresh model configuration cache...")
+    async with _cache_lock:
+        new_config = await fetch_and_parse_models_config()
+        if new_config is not None:
+            _model_cache = new_config
+            print("Model configuration cache refreshed successfully.")
+            return True
+        else:
+            print("ERROR: Failed to refresh model configuration cache.")
+            # Optionally, decide if we want to clear the old cache or keep it
+            # _model_cache = {"vertex_models": [], "vertex_express_models": []} # To clear
+            return False