#!/usr/bin/env python3
#
# Copyright (c) 2022 Project CHIP Authors
#
# 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.
#

import argparse
import configparser
import logging
import os
import subprocess
from collections import namedtuple
from pathlib import Path


class PlatformAction(argparse.Action):
    """Expand comma- or space-separated platform tokens and validate against ALL_PLATFORMS."""

    def __call__(self, parser, namespace, values, option_string=None):
        items = []
        for value in values:
            for item in value.split(','):
                item = item.strip()
                if item:
                    items.append(item)
        setattr(namespace, self.dest, items)


log = logging.getLogger(__name__)

CHIP_ROOT = next(filter(lambda p: (p / 'SPECIFICATION_VERSION').is_file(), Path(__file__).parents))

ALL_PLATFORMS = {
    'ameba',
    'android',
    'asr',
    'bl602',
    'bouffalolab',
    'cc13xx_26xx',
    'cc32xx',
    'darwin',
    'silabs',
    'esp32',
    'infineon',
    'nxp',
    'rw61x',
    'linux',
    'nrfconnect',
    'nuttx',
    'qpg',
    'realtek',
    'stm32',
    'telink',
    'tizen',
    'webos',
    'genio',
    'silabs_docker',
    'unit_tests'
}

Module = namedtuple('Module', 'name path platforms recursive')


def load_module_info() -> None:
    config = configparser.ConfigParser()
    config.read(os.path.join(CHIP_ROOT, '.gitmodules'))

    for name, module in config.items():
        if name != 'DEFAULT':
            platforms = module.get('platforms', '').split(',')
            platforms = set(filter(None, platforms))
            assert not (
                platforms - ALL_PLATFORMS), "Submodule's platform not contained in ALL_PLATFORMS"

            # Check for explicitly excluded platforms
            excluded_platforms = module.get('excluded-platforms', '').split(',')
            excluded_platforms = set(filter(None, excluded_platforms))
            assert not (
                excluded_platforms - ALL_PLATFORMS), "Submodule excluded on platforms not contained in ALL_PLATFORMS"

            if len(excluded_platforms) != 0:
                if len(platforms) == 0:
                    platforms = ALL_PLATFORMS
                platforms = platforms - excluded_platforms

            recursive = module.getboolean('recursive', False)
            name = name.replace('submodule "', '').replace('"', '')
            yield Module(name=name, path=module['path'], platforms=platforms, recursive=recursive)


def module_matches_platforms(module: Module, platforms: set) -> bool:
    # If the module is not associated with any specific platform, treat it as a match.
    if not module.platforms:
        return True
    return bool(platforms & module.platforms)


def module_initialized(module: Module) -> bool:
    return bool(os.listdir(os.path.join(CHIP_ROOT, module.path)))


def make_chip_root_safe_directory() -> None:
    # Can't use check_output, git will exit(1) if the setting has no existing value
    config = subprocess.run(['git', 'config', '--global', '--null', '--get-all',
                            'safe.directory'], stdout=subprocess.PIPE, text=True)
    existing = []
    if config.returncode != 1:
        config.check_returncode()
        existing = config.stdout.split('\0')
    if CHIP_ROOT not in existing:
        log.info("Adding CHIP_ROOT to global git safe.directory configuration")
        subprocess.check_call(
            ['git', 'config', '--global', '--add', 'safe.directory', CHIP_ROOT])


def checkout_modules(modules: list, shallow: bool, force: bool, recursive: bool, jobs: int) -> None:
    names = ', '.join([module.name for module in modules])
    log.info("Checking out '%s'", names)

    cmd = ['git', '-c', 'core.symlinks=true', '-C', CHIP_ROOT]
    cmd += ['submodule', '--quiet', 'update', '--init']
    cmd += ['--depth', '1'] if shallow else []
    cmd += ['--force'] if force else []
    cmd += ['--recursive'] if recursive else []
    cmd += ['--jobs', f'{jobs}'] if jobs else []
    module_paths = [module.path for module in modules]

    subprocess.check_call(cmd + module_paths)

    if recursive:
        # We've recursively checkouted all submodules.
        pass
    else:
        # We've checkouted all top-level submodules.
        # We're going to recursively checkout submodules whose recursive configuration is true.
        cmd += ['--recursive']
        module_paths = [module.path for module in modules if module.recursive]

        if module_paths:
            subprocess.check_call(cmd + module_paths)


def deinit_modules(modules: list, force: bool) -> None:
    names = ', '.join([module.name for module in modules])
    log.info("Deinitializing: '%s'", names)

    cmd = ['git', '-C', CHIP_ROOT, 'submodule', '--quiet', 'deinit']
    cmd += ['--force'] if force else []
    cmd += [module.path for module in modules]

    subprocess.check_call(cmd)


def main():
    logging.basicConfig(format='%(message)s', level=logging.INFO)

    parser = argparse.ArgumentParser(
        description='Checkout or update relevant git submodules')
    parser.add_argument('--allow-changing-global-git-config', action='store_true',
                        help='Allow global git options to be modified if necessary, e.g. safe.directory')
    parser.add_argument('--shallow', action='store_true',
                        help='Fetch submodules without history')
    parser.add_argument('--platform', nargs='+', default=[], action=PlatformAction,
                        metavar='{' + ','.join(sorted(ALL_PLATFORMS)) + '}',
                        help='Process submodules for specific platforms only (space- or comma-separated).')
    parser.add_argument('--force', action='store_true',
                        help='Perform action despite of warnings')
    parser.add_argument('--deinit-unmatched', action='store_true',
                        help='Deinitialize submodules for non-matching platforms')
    parser.add_argument('--recursive', action='store_true',
                        help='Recursive init of the listed submodules')
    parser.add_argument('--jobs', type=int, metavar='N',
                        help='Clone new submodules in parallel with N jobs')
    args = parser.parse_args()

    modules = list(load_module_info())

    invalid = [p for p in args.platform if p not in ALL_PLATFORMS]
    if invalid:
        invalid_display = ', '.join(sorted(set(invalid)))
        valid_choices = ', '.join(sorted(ALL_PLATFORMS))
        parser.error(f"Invalid platform(s): {invalid_display}. Valid choices: {valid_choices}")

    selected_platforms = set(args.platform)

    selected_modules = [
        m for m in modules if module_matches_platforms(m, selected_platforms)]
    unmatched_modules = [m for m in modules if not module_matches_platforms(
        m, selected_platforms) and module_initialized(m)]

    if args.allow_changing_global_git_config:
        make_chip_root_safe_directory()  # ignore directory ownership issues for sub-modules
    checkout_modules(selected_modules, args.shallow,
                     args.force, args.recursive, args.jobs)

    if args.deinit_unmatched and unmatched_modules:
        deinit_modules(unmatched_modules, args.force)


if __name__ == '__main__':
    main()