#!/usr/bin/env python3
# Copyright 2025 The Chromium Authors
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

import argparse
import glob
import os
import shutil
import subprocess
import sys
import tempfile

_SCRIPT_DIR = os.path.dirname(__file__)
_PARSER_SCRIPT = os.path.join(_SCRIPT_DIR,
                              '../public/tools/mojom/mojom_parser.py')
_GENERATOR_SCRIPT = os.path.join(
    _SCRIPT_DIR, '../public/tools/bindings/mojom_bindings_generator.py')


def removesuffix(string, suffix):
    if not suffix or not string.endswith(suffix):
        return string
    return string[:-len(suffix)]


def generate_bindings(input_dir, output_dir):
    if not os.path.isdir(output_dir):
        raise NotADirectoryError(
            f'Output directory "{output_dir}" must exist')

    with tempfile.TemporaryDirectory() as tmp_dir:
        tmp_modules_dir = os.path.join(tmp_dir, 'modules')
        tmp_bytecode_dir = os.path.join(tmp_dir, 'bytecode')
        tmp_bindings_dir = os.path.join(tmp_dir, 'bindings')
        os.mkdir(tmp_modules_dir)
        os.mkdir(tmp_bytecode_dir)
        os.mkdir(tmp_bindings_dir)

        mojom_files = glob.glob(os.path.join(input_dir, '*.test-mojom'))
        subprocess.run([
            'python3', _PARSER_SCRIPT, '--input-root', input_dir,
            '--add-module-metadata', 'webui_module_path="golden://test"',
            '--output-root', tmp_modules_dir, '--mojoms', *mojom_files
        ],
                       check=True)
        subprocess.run([
            'python3', _GENERATOR_SCRIPT, '-o', tmp_bytecode_dir, 'precompile'
        ],
                       check=True)
        # Paths to module files relative to the bindings output directory.
        mojom_modules = (os.path.join('../modules',
                                      removesuffix(module_filename, '-module'))
                         for module_filename in os.listdir(tmp_modules_dir))
        subprocess.run([
            'python3', _GENERATOR_SCRIPT, '-o', tmp_bindings_dir, 'generate',
            '--bytecode_path', tmp_bytecode_dir, '--generators', 'typescript',
            # typemap is hardcoded for now.
            '--typemap', f'{input_dir}/typemap.json',
            *mojom_modules
        ],
                       check=True)
        # Append '.golden' file extension to avoid presubmit checks.
        for entry in os.scandir(tmp_bindings_dir):
            os.rename(entry.path, entry.path + '.golden')
        shutil.copytree(tmp_bindings_dir, output_dir, dirs_exist_ok=True)


def main():
    parser = argparse.ArgumentParser(
        description='Generate mojo binding golden files.')
    parser.add_argument('--input-dir',
                        default=os.path.join(_SCRIPT_DIR, 'corpus'),
                        dest='input_dir',
                        help='directory containing input .mojom files')
    parser.add_argument(
        '--output-dir',
        default=os.path.join(_SCRIPT_DIR, 'generated/typescript'),
        dest='output_dir',
        help='empty directory in which to write generated bindings')
    args = parser.parse_args(sys.argv[1:])

    generate_bindings(args.input_dir, args.output_dir)


if __name__ == "__main__":
    main()