#!/usr/bin/env python
# Copyright 2019 The Pigweed 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
#
#     https://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.
"""Installs or updates prebuilt tools.

Must be tested with Python 2 and Python 3.

The stdout of this script is meant to be executed by the invoking shell.
"""

from __future__ import print_function

import argparse
import glob
import os
import subprocess
import sys

SCRIPT_ROOT = os.path.abspath(os.path.dirname(__file__))
GIT_ROOT = subprocess.check_output(['git', 'rev-parse', '--show-toplevel'],
                                   cwd=SCRIPT_ROOT).decode('utf-8').strip()


def parse(argv=None):
    """Parse arguments."""

    parser = argparse.ArgumentParser(description=__doc__.splitlines()[0])
    parser.add_argument(
        '--install-dir',
        dest='root_install_dir',
        default=os.path.join(GIT_ROOT, '.cipd'),
    )
    parser.add_argument('--ensure-file', dest='ensure_files', action='append')
    parser.add_argument('--cipd',
                        default=os.path.join(SCRIPT_ROOT, 'wrapper.py'))
    parser.add_argument('--cache-dir',
                        default=os.environ.get(
                            'CIPD_CACHE_DIR',
                            os.path.expanduser('~/.cipd-cache-dir')))

    return parser.parse_args(argv)


def check_auth(cipd):
    """Check logged into CIPD."""
    try:
        subprocess.check_output([cipd, 'auth-info'], stderr=subprocess.STDOUT)
        return True

    except subprocess.CalledProcessError:
        print('=' * 60, file=sys.stderr)
        print('ERROR: not logged into CIPD--please run this command:',
              file=sys.stderr)
        print(cipd, 'auth-login', file=sys.stderr)
        print('=' * 60, file=sys.stderr)

        return False


def update(
    cipd,
    ensure_files,
    root_install_dir,
    cache_dir,
    env_vars=None,
):
    """Grab the tools listed in ensure_files."""

    if not check_auth(cipd):
        return

    # TODO(mohrr) use os.makedirs(..., exist_ok=True).
    if not os.path.isdir(root_install_dir):
        os.makedirs(root_install_dir)

    if env_vars:
        env_vars.prepend('PATH', root_install_dir)
        env_vars.set('CIPD_INSTALL_DIR', root_install_dir)
        env_vars.set('CIPD_CACHE_DIR', cache_dir)

    # Run cipd for each ensure file.
    default_ensures = os.path.join(SCRIPT_ROOT, '*.ensure')
    for ensure_file in ensure_files or glob.glob(default_ensures):
        install_dir = os.path.join(root_install_dir,
                                   os.path.basename(ensure_file))

        cmd = [
            cipd,
            'ensure',
            '-ensure-file', ensure_file,
            '-root', install_dir,
            '-log-level', 'warning',
            '-max-threads', '0',  # 0 means use CPU count.
        ]  # yapf: disable

        print(*cmd, file=sys.stderr)
        subprocess.check_call(cmd, stdout=sys.stderr)

        # Set environment variables so tools can later find things under, for
        # example, 'share'.
        name = ensure_file
        if os.path.splitext(name)[1] == '.ensure':
            name = os.path.splitext(name)[0]
        name = os.path.basename(name)

        if env_vars:
            # Some executables get installed at top-level and some get
            # installed under 'bin'.
            env_vars.prepend('PATH', install_dir)
            env_vars.prepend('PATH', os.path.join(install_dir, 'bin'))
            env_vars.set('{}_CIPD_INSTALL_DIR'.format(name.upper()),
                         install_dir)


if __name__ == '__main__':
    update(**vars(parse()))
    sys.exit(0)