#!/usr/bin/env python3
"""
This script is a wrapper around `./mach lint` that aims to facilitate fixing a
single file from stdin, and dumping the changed file to stdout.

It exists to redirect stdout to stderr, so we can be sure that mach or mozlint
won't ever dump logs to stdout which would then end up being incorporated into
a file.
"""

import importlib.machinery
import importlib.util
import os
import sys
import tempfile
from pathlib import Path

# Redirect all stdout to stderr
old_stdout = sys.stdout
sys.stdout = sys.stderr

REPO_ROOT = Path(__file__).parent.parent.parent

def main():
    mach_path = REPO_ROOT / "mach"
    loader = importlib.machinery.SourceFileLoader("mach", str(mach_path))
    spec = importlib.util.spec_from_loader("mach", loader)
    assert spec
    assert spec.loader

    mach = importlib.util.module_from_spec(spec)
    spec.loader.exec_module(mach)

    assert len(sys.argv) == 2
    temp = tempfile.NamedTemporaryFile(mode="wb+", delete=False)
    try:
        # Close the file so we don't run into permissions errors trying to read
        # the file later when other processes have written to it.
        # See https://bugzilla.mozilla.org/show_bug?cgi?id=1948069
        temp.close()

        args = [
            "lint",
            "--fix",
            "--stdin-filename",
            sys.argv[1],
            "--dump-stdin-file",
            temp.name,
        ]

        try:
            mach.main(args)
        except SystemExit as e:
            if e.code != 0:
                raise

        # Restore stdout and dump the file.
        sys.stdout = old_stdout

        # Now that the other processes have written to the file, we can re-open
        # it and read it.
        #
        # We have to write directly to stdout's buffer with bytes because
        # otherwise writing text will automatically convert LF to CRLF on
        # Windows.
        with open(temp.name, "rb") as f:
            sys.stdout.buffer.write(f.read())
    finally:
        os.unlink(temp.name)


if __name__ == "__main__":
    main()