#!/usr/bin/env python3
# Copyright 2023 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.
'''Builds the gnrt tool and runs it to generate stdlib GN rules.'''

import argparse
import os
import sys
import tempfile

# Get variables and helpers from Clang update script.
sys.path.append(
    os.path.join(
        os.path.dirname(os.path.abspath(__file__)), '..', 'clang', 'scripts'
    )
)
from build import RunCommand
from update import CHROMIUM_DIR

sys.path.append(
    os.path.join(os.path.dirname(os.path.abspath(__file__)), '..', 'crates')
)
from run_gnrt import RunGnrt

from build_bindgen import EXE
from build_rust import (
    RustTargetTriple,
    RUST_SRC_DIR,
    RUST_BETA_SYSROOT_DIR,
    InstallRustBetaSysroot,
)
from update_rust import RUST_REVISION

BUILD_RUST_PY_PATH = os.path.join(
    CHROMIUM_DIR, 'tools', 'rust', 'build_rust.py'
)


def main():
    parser = argparse.ArgumentParser(
        description='build and run gnrt for stdlib'
    )
    parser.add_argument(
        '--skip-prep',
        action='store_true',
        help='do not fetch dependencies, assuming a previous successful run.',
    )
    parser.add_argument(
        '--out-dir',
        help='cache artifacts in specified directory instead of a temp dir.',
    )
    args = parser.parse_args()

    if not args.skip_prep:
        # This step gets the dependencies in the Rust git checkout.
        RunCommand([BUILD_RUST_PY_PATH, '--sync-for-gnrt'])

        # Get a Rust sysroot to build gnrt with.
        InstallRustBetaSysroot(RUST_REVISION, [RustTargetTriple()])

    # Build and run gnrt to update the stdlib GN rules.
    if args.out_dir:
        run_gnrt(RUST_BETA_SYSROOT_DIR, args.out_dir)
    else:
        with tempfile.TemporaryDirectory() as out_dir:
            run_gnrt(RUST_BETA_SYSROOT_DIR, out_dir)


def run_gnrt(sysroot_dir, out_dir):
    gnrt_args = [
        'gen',
        f'--for-std={os.path.relpath(RUST_SRC_DIR, CHROMIUM_DIR)}',
    ]
    RunGnrt(sysroot_dir, out_dir, gnrt_args)


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