libdot/bin/black

#!/usr/bin/env python3
# Copyright 2022 The ChromiumOS Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Run black with the right settings."""

import argparse
import functools
import logging
import shutil
import subprocess
import sys

import libdot


filter_known_files = libdot.pylint.filter_known_files


@functools.lru_cache(maxsize=1)
def find_black() -> str:
    """Figure out the name of the black tool."""
    # Prefer our vpython copy if possible.
    if shutil.which("vpython3"):
        return libdot.BIN_DIR / "black-vpython"

    # If there's no black, give up.
    if not shutil.which("black"):
        logging.error(
            "unable to locate black; please install:\n"
            "sudo apt-get install black"
        )
        sys.exit(1)

    return "black"


def setup() -> None:
    """Initialize the tool settings."""
    find_black()


def run(argv=(), **kwargs) -> subprocess.CompletedProcess:
    """Run the tool directly."""
    setup()

    cmd = [find_black(), "--quiet"] + list(argv)
    return libdot.run(cmd, **kwargs)


def perform(
    # pylint: disable=unused-argument
    argv=(),
    paths=(),
    fix=False,
    gerrit_comments_file=None,
) -> bool:
    """Run high level tool logic."""
    argv = list(argv)
    paths = list(paths)

    if not fix:
        argv += ["--check", "--diff"]

    # TODO(vapier): Add support for Gerrit comments.

    result = run(argv + paths, check=False)
    return result.returncode == 0


def get_parser() -> argparse.ArgumentParser:
    """Get a command line parser."""
    parser = libdot.ArgumentParser(description=__doc__, short_options=False)
    parser.add_argument(
        "--fix",
        action="store_true",
        help="Fix formatting issues.",
    )
    parser.add_argument(
        "--gerrit-comments-file",
        help="Save errors for posting files to Gerrit.",
    )
    parser.add_argument("paths", nargs="*", help="Paths to format.")
    return parser


def main(argv: list[str]) -> int:
    """The main func!"""
    parser = get_parser()
    opts, args = parser.parse_known_args(argv)

    return (
        0
        if perform(
            argv=args,
            paths=opts.paths,
            fix=opts.fix,
            gerrit_comments_file=opts.gerrit_comments_file,
        )
        else 1
    )


if __name__ == "__main__":
    sys.exit(main(sys.argv[1:]))