"""Object Generators (AKA Oracles)"""

import yaml

from .oracle.base import Oracle
from .oracle.object_generator import ObjectGeneratorOracle
from .oracle.random_choice import RandomChoiceOracle

TYPE_CLASSES = {
    "object-generator": ObjectGeneratorOracle,
    "random-choice": RandomChoiceOracle,
}


def read_datafile(filename: str) -> Oracle:
    """Read a datafile in YAML format"""

    with open(filename, "r", encoding="utf-8") as fhand:
        data = yaml.safe_load(fhand)

    if not isinstance(data, dict):
        raise TypeError("Generator data must be an YAML object")

    if (generator_type := data.get("type")) not in TYPE_CLASSES:
        raise ValueError(f"No information on how to handle {generator_type} data")

    handler_class = TYPE_CLASSES[generator_type]

    return handler_class(data)