from __future__ import annotations
import yaml
from pathlib import Path
from typing import List, Union
from specs import Spec, DirectorySpec, VolumeSpec
import skeleton


def read_specs_file(path: Union[str, Path]) -> List[Spec]:
    with open(path, "r") as yaml_file:
        data = yaml.safe_load(yaml_file)

    categories = [("directories", DirectorySpec), ("volumes", VolumeSpec)]

    specs = []

    for key, class_name in categories:
        if not data["specs"].get(key):
            continue

        # Check what defaults are present
        defaults = {}
        if data.get("defaults"):
            if data["defaults"].get("all"):
                defaults = skeleton.merge(defaults, data["defaults"]["all"])

            if data["defaults"].get(key):
                defaults = skeleton.merge(defaults, data["defaults"][key])

        specs.extend(
            [
                class_name.from_dict(name, spec, defaults)
                for name, spec in data["specs"][key].items()
            ]
        )

    return specs