import os
from loguru import logger

# Placeholder for actual LLM integration.
# In a full implementation you would import LangChain and configure the provider
# based on environment variables (e.g., Gemini, OpenRouter, Ollama, etc.).

def chat(message: str) -> str:
    """Return a simple response indicating which provider is active.

    In a real agent this would call the selected LLM and possibly use tools.
    """
    provider = os.getenv("ACTIVE_PROVIDER", "mock")
    logger.info(f"provider={provider} message_len={len(message)}")
    # Simple mock response – replace with actual LLM call.
    return f"\u2705 ({provider}) {message}"