"""Factory function for creating AI router instances."""

from typing import Any, Optional
from .base import AIRouter
from .gemini import Gemini
from .openai_compatible import OpenAI
from .cohere import Cohere


def create_router(
    provider: str,
    model: Optional[str] = None,
    api_key: Optional[str] = None,
    **kwargs: Any
) -> AIRouter:
    """Create an AI router instance based on provider.
    
    Args:
        provider: Provider name (openai, gemini, cohere)
        model: Model to use (provider-specific default if not provided)
        api_key: API key (optional if set in environment)
        **kwargs: Additional provider-specific configuration
        
    Returns:
        AIRouter instance
        
    Raises:
        ValueError: If provider is unknown
    """
    provider = provider.lower()
    
    if provider == "openai":
        return OpenAI(
            model=model or "gpt-4o",
            api_key=api_key,
            **kwargs
        )
    elif provider in ["gemini", "google"]:
        return Gemini(
            model=model or "gemini-2.0-flash-001",
            api_key=api_key,
            **kwargs
        )
    elif provider == "cohere":
        return Cohere(
            model=model or "command-r-plus",
            api_key=api_key,
            **kwargs
        )
    else:
        raise ValueError(f"Unknown provider: {provider}")


# Convenience alias that matches the test expectations
def AIRouter(provider: str, **kwargs: Any) -> AIRouter:
    """Factory function alias for backward compatibility."""
    return create_router(provider, **kwargs)