#
# Copyright (C) 2018 The Android Open Source Project
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
"""Generates a intermediate file for using in making a compilation database.

The intermediate file is also a JSON file, but only encodes the data for a
single output.
"""
from __future__ import print_function

import argparse
import json
import os
from pathlib import Path

from shlex import join


def get_argument_parser() -> argparse.ArgumentParser:
    """Parses and returns command line arguments."""
    parser = argparse.ArgumentParser()

    parser.add_argument(
        "-o",
        "--output",
        type=os.path.realpath,  # type: ignore
        required=True,
        help="Path to output file",
    )

    parser.add_argument(
        "-d",
        "--directory",
        type=os.path.realpath,  # type: ignore
        help="Working directory for the compile command.",
    )

    parser.add_argument("-f", "--file", help="Source file.")
    parser.add_argument("--object-file", help="Object file.")

    parser.add_argument(
        "--command-file",
        type=os.path.realpath,  # type: ignore
        help="Compilation command list file.",
    )

    parser.add_argument(
        "compile_command",
        metavar="COMPILE_COMMAND",
        nargs=argparse.REMAINDER,
        help="Compilation command.",
    )

    return parser


def main() -> None:
    """Program entry point."""
    parser = get_argument_parser()
    args = parser.parse_args()

    if args.command_file and args.compile_command:
        parser.error("--command-file and COMPILE_COMMAND are mutually exclusive")

    if not args.command_file and not args.compile_command:
        parser.error("Either --command-file or COMPILE_COMMAND is required.")

    command = join(args.compile_command)
    if args.command_file:
        command = Path(args.command_file).read_text(encoding="utf-8").strip()

    with open(args.output, "w", encoding="utf-8") as out_file:
        json.dump(
            {
                "directory": args.directory,
                "file": args.file,
                "output": args.object_file,
                "command": command,
            },
            out_file,
        )


if __name__ == "__main__":
    main()