"""Utility & helper functions."""

from __future__ import annotations

import typing

from langchain.chat_models import init_chat_model
from langchain_core.language_models import BaseChatModel
from langchain_core.messages import BaseMessage


def get_message_text(msg: BaseMessage) -> str:
    """Get the text content of a message."""
    content = msg.content
    if isinstance(content, str):
        return content
    elif isinstance(content, dict):
        return content.get("text", "")
    else:
        txts = [c if isinstance(c, str) else (c.get("text") or "") for c in content]
        return "".join(txts).strip()


def load_chat_model(fully_specified_name: str) -> BaseChatModel:
    """Load a chat model from a fully specified name.

    Args:
        fully_specified_name (str): String in the format 'provider/model'.
    """
    provider, model = fully_specified_name.split("/", maxsplit=1)
    return init_chat_model(model, model_provider=provider)


class State:
    """An object that can be used to store arbitrary state."""

    _state: dict[str, typing.Any]

    def __init__(self, state: dict[str, typing.Any] | None = None):
        if state is None:
            state = {}
        super().__setattr__("_state", state)

    def __setattr__(self, key: typing.Any, value: typing.Any) -> None:
        self._state[key] = value

    def __getattr__(self, key: typing.Any) -> typing.Any:
        try:
            return self._state[key]
        except KeyError:
            message = "'{}' object has no attribute '{}'"
            raise AttributeError(message.format(self.__class__.__name__, key))

    def __delattr__(self, key: typing.Any) -> None:
        del self._state[key]