#!/usr/bin/env fuchsia-vendored-python
# Copyright 2023 The Fuchsia Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import difflib
import sys


def main():
    parser = argparse.ArgumentParser(
        description="Compares drivers lists and outputs diffs"
    )
    parser.add_argument(
        "--drivers-list1", type=argparse.FileType("r"), required=True
    )
    parser.add_argument(
        "--drivers-list2", type=argparse.FileType("r"), required=True
    )
    parser.add_argument("--output", type=argparse.FileType("w"), required=True)
    args = parser.parse_args()

    drivers_list1 = sorted(args.drivers_list1.readlines())
    drivers_list2 = sorted(args.drivers_list2.readlines())
    diff = difflib.unified_diff(
        drivers_list1,
        drivers_list2,
        args.drivers_list1.name,
        args.drivers_list2.name,
        lineterm="",
    )
    diffstr = "\n".join(diff)
    args.output.write(diffstr)

    if len(diffstr) != 0:
        print(f"Error: non-empty diff\n\n{diffstr}", file=sys.stderr)
        return 1


if __name__ == "__main__":
    sys.exit(main())