#!/usr/bin/env python3
"""Read bump-my-version's current_version from a local file or Git ref."""

from __future__ import annotations

import argparse
import subprocess
import tomllib


def parse_args() -> argparse.Namespace:
	parser = argparse.ArgumentParser()
	parser.add_argument("config_file")
	parser.add_argument("--ref")
	return parser.parse_args()


def main() -> None:
	args = parse_args()
	try:
		if args.ref:
			content = subprocess.check_output(
				["git", "show", f"{args.ref}:{args.config_file}"],
			)
		else:
			with open(args.config_file, "rb") as config_file:
				content = config_file.read()
	except (OSError, subprocess.CalledProcessError) as error:
		raise SystemExit(f"Could not load {args.config_file}: {error}") from error

	try:
		version = tomllib.loads(content.decode())["tool"]["bumpversion"]["current_version"]
	except (KeyError, TypeError, UnicodeDecodeError, tomllib.TOMLDecodeError) as error:
		raise SystemExit(
			f"Could not read tool.bumpversion.current_version from {args.config_file}: {error}"
		) from error

	if not isinstance(version, str):
		raise SystemExit("tool.bumpversion.current_version must be a string")
	print(version)


if __name__ == "__main__":
	main()