from typing import Union
from io import TextIOWrapper
import json


def compose_config(
    config: Union[TextIOWrapper, None],
    credentials: Union[TextIOWrapper, None],
    queries: Union[TextIOWrapper, None],
) -> dict:
    """
    Receive the CLI arguments and compose a session config.

    :param config: file pointer to a full config file.
    :param credentials: file pointer to a credentials file.
    :param queries: file pointer to a queries file.
    :return: a dict with the composed configuration.
    """

    if config is not None:
        DeprecationWarning(
            "Usage of a full config file will be deprecated. Instead, use the credentials and queries arguments."
        )
        return json.load(config)

    if credentials is None or queries is None:
        raise ValueError(
            "You need to provide both --credentials and --queries arguments."
        )

    # Merge both into one dict so it follows the same structure as a full config file
    return {**json.load(credentials), **json.load(queries)}