src/developer/ffx/build/gn_generate_cmd.py

#!/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.
#
import argparse
import filecmp
import os
import shutil
import sys
import tempfile

from jinja2 import Environment, FileSystemLoader


def to_camel_case(snake_str: str) -> str:
    components = snake_str.split("_")
    return "".join(x.title() for x in components[0:])


def wrap_deps(dep: str) -> dict[str, str]:
    return {"enum": to_camel_case(dep), "lib": dep + "_args"}


def main(args_list: list[str] | None = None) -> int:
    parser = argparse.ArgumentParser(description="Generate FFX Command struct")

    parser.add_argument(
        "--out", help="The output file to generate", required=True
    )

    parser.add_argument(
        "--deps",
        help="Comma-seperated libraries to generate code from",
        required=True,
    )

    parser.add_argument(
        "--template",
        help="The template file to use to generate code",
        required=True,
    )

    if args_list:
        args = parser.parse_args(args_list)
    else:
        args = parser.parse_args()

    template_dir, template_name = os.path.split(args.template)
    env = Environment(
        loader=FileSystemLoader(template_dir),
        trim_blocks=True,
        lstrip_blocks=True,
    )
    template = env.get_template(template_name)
    libraries = args.deps.split(",")
    deps = map(wrap_deps, libraries)
    temp_file = tempfile.NamedTemporaryFile(mode="w")
    with open(temp_file.name, "w") as file:
        file.write(template.render(deps=deps))
        file.flush()
        if not os.path.isfile(args.out) or not filecmp.cmp(
            temp_file.name, args.out, shallow=False
        ):
            shutil.copyfile(temp_file.name, args.out)
    return 0


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