Source code for dawsonia.config

"""configuration file parsing utilities."""

from __future__ import annotations

import os
from functools import lru_cache
from pathlib import Path
from typing import Any, Optional

import click
import tomli as tomllib

from .typing import TableFormatFile




@lru_cache
def _read_toml(file_or_path: str | Path, _mtime: int) -> dict:
    """Read TOML configuration file into a dictionary"""
    path = Path(file_or_path)

    if not path.exists():
        raise FileNotFoundError(str(path))

    with path.open("rb") as fp:
        config = tomllib.load(fp)
    return config





def read_table_formats(config_file: str | Path) -> TableFormatFile:
    return _read_toml(
        config_file, os.path.getmtime(config_file)
    )  # type:ignore[return-value]





def read_configfile(config_file: str | Path) -> dict[str, dict[str, dict]]:
    return _read_toml(config_file, os.path.getmtime(config_file))





def set_default_from_configfile(ctx: click.Context, _, value) -> Optional[str]:
    """Set / override CLI context's arguments from configfile"""
    config_file = Path(value)
    command_name = ctx.command.name
    print(f"Reading {config_file = }")
    if config_file.exists() and command_name:
        config = read_configfile(config_file)
        if command_name not in config["dawsonia"]:
            raise KeyError(
                f"Config provided but section [dawsonia.{command_name}] seems to be"
                " missing."
            )

        ctx.default_map = config["dawsonia"].get(command_name)
    return value



config_cli_names = ("-c", "--config")
# Default keyword arguments for a subcommand which accepts a configuration file
# option.
config_kwargs: dict[str, Any] = dict(
    help="TOML configuration file as an alternative for CLI arguments.",
    callback=set_default_from_configfile,
    is_eager=True,
    expose_value=False,
)