feat: Add LLM connection test and model discovery

pixelle_video/llm_presets.py

@@ -25,37 +25,70 @@
         "base_url": "https://dashscope.aliyuncs.com/compatible-mode/v1",
         "model": "qwen-max",
         "api_key_url": "https://bailian.console.aliyun.com/?tab=model#/api-key",
+        # Connection test and model discovery fields
+        "supports_connection_test": True,
+        "models_url": "https://dashscope.aliyuncs.com/compatible-mode/v1/models",
+        "models_response_path": "data",
+        "model_id_field": "id",
+        "requires_api_key": True,
     },
     {
         "name": "OpenAI",
         "base_url": "https://api.openai.com/v1",
         "model": "gpt-4o",
         "api_key_url": "https://platform.openai.com/api-keys",
+        # Connection test and model discovery fields
+        "supports_connection_test": True,
+        "models_url": "https://api.openai.com/v1/models",
+        "models_response_path": "data",
+        "model_id_field": "id",
+        "requires_api_key": True,
     },
     {
         "name": "Claude",
         "base_url": "https://api.anthropic.com/v1/",
         "model": "claude-sonnet-4-5",
         "api_key_url": "https://console.anthropic.com/settings/keys",
+        # Claude uses Anthropic's native API which is not OpenAI-compatible
+        # Connection test and model discovery are NOT supported
+        "supports_connection_test": False,
+        "requires_api_key": True,
     },
     {
         "name": "DeepSeek",
         "base_url": "https://api.deepseek.com",
         "model": "deepseek-chat",
         "api_key_url": "https://platform.deepseek.com/api_keys",
+        # Connection test and model discovery fields
+        "supports_connection_test": True,
+        "models_url": "https://api.deepseek.com/models",
+        "models_response_path": "data",
+        "model_id_field": "id",
+        "requires_api_key": True,
     },
     {
         "name": "Ollama",
         "base_url": "http://localhost:11434/v1",
         "model": "llama3.2",
         "api_key_url": "https://ollama.com/download",
-        "default_api_key": "ollama",  # Required by OpenAI SDK but ignored by Ollama
+        # Ollama uses native API for model listing (not OpenAI-compatible endpoint)
+        "supports_connection_test": True,
+        "models_url": "http://localhost:11434/api/tags",
+        "models_response_path": "models",
+        "model_id_field": "name",
+        "requires_api_key": False,  # Ollama doesn't need API key
     },
     {
         "name": "Moonshot",
         "base_url": "https://api.moonshot.cn/v1",
         "model": "moonshot-v1-8k",
         "api_key_url": "https://platform.moonshot.cn/console/api-keys",
+        # Connection test and model discovery fields
+        "supports_connection_test": True,
+        "models_url": "https://api.moonshot.cn/v1/models",
+        "models_response_path": "data",
+        "model_id_field": "id",
+        "requires_api_key": True,
     },
 ]
 
@@ -76,7 +109,7 @@ def get_preset(name: str) -> Dict[str, Any]:
 def find_preset_by_base_url_and_model(base_url: str, model: str) -> str | None:
     """
     Find preset name by base_url and model
-    
+
     Returns:
         Preset name if found, None otherwise
     """
@@ -85,3 +118,58 @@ def find_preset_by_base_url_and_model(base_url: str, model: str) -> str | None:
             return preset["name"]
     return None
 
+
+def get_models_config(preset_name: str) -> Dict[str, Any]:
+    """
+    Get model listing endpoint configuration for a preset.
+
+    Args:
+        preset_name: Name of the LLM preset
+
+    Returns:
+        Dict with keys: models_url, models_response_path, model_id_field
+        Falls back to standard OpenAI format for unknown presets
+    """
+    preset = get_preset(preset_name)
+    if preset and preset.get("supports_connection_test"):
+        return {
+            "models_url": preset.get("models_url"),
+            "models_response_path": preset.get("models_response_path", "data"),
+            "model_id_field": preset.get("model_id_field", "id"),
+        }
+    # Default OpenAI-compatible format for unknown presets
+    return {
+        "models_url": None,
+        "models_response_path": "data",
+        "model_id_field": "id",
+    }
+
+
+def supports_connection_test(preset_name: str) -> bool:
+    """
+    Check if a preset supports connection testing.
+
+    Args:
+        preset_name: Name of the LLM preset
+
+    Returns:
+        True if connection test is supported, False otherwise
+    """
+    preset = get_preset(preset_name)
+    return preset.get("supports_connection_test", False) if preset else False
+
+
+def requires_api_key(preset_name: str) -> bool:
+    """
+    Check if a preset requires an API key.
+
+    Args:
+        preset_name: Name of the LLM preset
+
+    Returns:
+        True if API key is required, False otherwise (e.g., Ollama)
+    """
+    preset = get_preset(preset_name)
+    # Default to True if not specified (most providers need API key)
+    return preset.get("requires_api_key", True) if preset else True
+