from typing import Optional

from .base_client import BaseLLMClient

# Providers that use the OpenAI-compatible chat completions API
_OPENAI_COMPATIBLE = (
    "openai", "xai", "deepseek", "qwen", "glm", "ollama", "openrouter",
)


def create_llm_client(
    provider: str,
    model: str,
    base_url: Optional[str] = None,
    **kwargs,
) -> BaseLLMClient:
    """Create an LLM client for the specified provider.

    Client modules are imported lazily so that collecting tests or importing
    the package does not trigger heavy LLM SDK initialization.

    Args:
        provider: LLM provider name
        model: Model name/identifier
        base_url: Optional base URL for API endpoint
        **kwargs: Additional provider-specific arguments

    Returns:
        Configured BaseLLMClient instance

    Raises:
        ValueError: If provider is not supported
    """
    provider_lower = provider.lower()

    if provider_lower in _OPENAI_COMPATIBLE:
        from .openai_client import OpenAIClient
        return OpenAIClient(model, base_url, provider=provider_lower, **kwargs)

    if provider_lower == "anthropic":
        from .anthropic_client import AnthropicClient
        return AnthropicClient(model, base_url, **kwargs)

    if provider_lower == "google":
        from .google_client import GoogleClient
        return GoogleClient(model, base_url, **kwargs)

    if provider_lower == "azure":
        from .azure_client import AzureOpenAIClient
        return AzureOpenAIClient(model, base_url, **kwargs)

    raise ValueError(f"Unsupported LLM provider: {provider}")