import json

from langchain_openai import ChatOpenAI

from config import Settings, settings as default_settings


class SafeChatOpenAI(ChatOpenAI):
    """ChatOpenAI subclass that handles providers returning string responses."""

    def _create_chat_result(self, response, generation_info=None):
        if isinstance(response, str):
            response = json.loads(response)
        return super()._create_chat_result(response, generation_info)


def get_llm(s: Settings | None = None, temperature: float = 0.1) -> SafeChatOpenAI:
    s = s or default_settings
    if not s.is_llm_configured:
        raise RuntimeError(
            "LLM not configured. Set LLM_BASE_URL and LLM_MODEL in .env "
            "or via the Settings panel in the UI."
        )
    return SafeChatOpenAI(
        base_url=s.llm_base_url,
        model=s.llm_model,
        api_key=s.llm_api_key or "not-needed",
        temperature=temperature,
    )