"""
Module implementing the 'Chat' class and functions for managing a chat history.
"""
import pathlib
from dataclasses import dataclass
from typing import TypeVar, Type, Optional
from .message import Message, MessageFilter, MessageError

ChatInst = TypeVar('ChatInst', bound='Chat')


class ChatError(Exception):
    pass


@dataclass
class Chat:
    """
    Class containing a complete chat history.
    """
    messages: list[Message]

    @classmethod
    def from_dir(cls: Type[ChatInst],
                 path: pathlib.Path,
                 glob: Optional[str] = None,
                 mfilter: Optional[MessageFilter] = None) -> ChatInst:
        """
        Create a Chat instance from the message in the given directory.
        If 'glob' is specified, files will be filtered using path.glob(),
        otherwise we use path.iterdir(). Messages are created using
        'Message.from_file()' with the optional MessageFilter.
        """
        messages: list[Message] = []
        file_iter = path.glob(glob) if glob else path.iterdir()
        for file_path in file_iter:
            if file_path.is_file():
                try:
                    message = Message.from_file(file_path, mfilter)
                    if message:
                        messages.append(message)
                except MessageError as e:
                    print(f"Error processing message in file {file_path}: {str(e)}")
        return cls(messages)