#!/usr/bin/env fuchsia-vendored-python
# Copyright 2020 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.
# Lint as: python3

import argparse
import json
import os
import sys


# Generates shebang files for binaries so they can be invoked from the shell.
# Generated files look like this:
# #!resolve fuchsia-pkg://fuchsia.com/<package-name>#bin/<bin-name>
def main():
    parser = argparse.ArgumentParser(
        "Generate shebang files for shell binaries"
    )
    parser.add_argument("--package-name", required=True)
    parser.add_argument(
        "--input-distribution-manifest",
        required=True,
        type=argparse.FileType("r"),
        help="Path to a distribution manifest with all shell binaries",
    )
    parser.add_argument(
        "--output-directory",
        required=True,
        help="Path to a directory to store generated shebang files",
    )
    parser.add_argument(
        "--output-distribution-manifest",
        required=True,
        help="Path to write output distribution manifest",
    )
    parser.add_argument(
        "--depfile",
        required=True,
        help="Depfile for listing generated shebang files as additional inputs",
    )
    args = parser.parse_args()

    input_dist = json.load(args.input_distribution_manifest)
    output_dist = []
    shebang_files = []

    for dist in input_dist:
        dest = dist["destination"]
        if not dest.startswith("bin/"):
            continue
        shebang_file = os.path.join(
            args.output_directory, "__untraced_shebangs__", dest
        )
        shebang_files.append(shebang_file)
        os.makedirs(os.path.dirname(shebang_file), exist_ok=True)
        with open(shebang_file, "w") as f:
            f.write(
                f"#!resolve fuchsia-pkg://fuchsia.com/{args.package_name}#{dest}\n"
            )
        output_dist.append(dict(dist, source=shebang_file))

    with open(
        args.output_distribution_manifest, "w"
    ) as output_distribution_manifest:
        json.dump(
            output_dist,
            output_distribution_manifest,
            indent=2,
            sort_keys=True,
            separators=(",", ": "),
        )

    with open(args.depfile, "w") as depfile:
        depfile.write(
            "{}: {}\n".format(
                args.output_distribution_manifest.name, " ".join(shebang_files)
            )
        )

    return 0


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