nassh/bin/fonts

#!/usr/bin/env python3
# Copyright 2020 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Download web fonts to bundle with nassh. See ../doc/fonts.md"""

import os
import shutil
import sys

import nassh
import libdot


# The hash of the fonts that we maintain.
# Allow a long line for easy automated updating.
# pylint: disable=line-too-long
FONTS_HASH = 'd6dc5eaf459abd058cd3aef1e25963fde893f9d87f5f55f340431697ce4b3506'
# pylint: enable=line-too-long

# Bucket maintained by us.
FONTS_GS_FRAGMENT = 'chromeos-localmirror/secureshell/distfiles'
FONTS_GS_URI = f'gs://{FONTS_GS_FRAGMENT}'
FONTS_BASE_URI = f'https://storage.googleapis.com/{FONTS_GS_FRAGMENT}'

# The nassh fonts path.
FONTS_DIR = nassh.DIR / 'fonts'


def fonts_update():
    """Download & update our copy of fonts."""
    hash_file = FONTS_DIR / '.hash'
    old_hash = None
    try:
        with open(hash_file, 'r', encoding='utf-8') as fp:
            old_hash = fp.read().strip()
    except FileNotFoundError:
        pass

    # In case of an upgrade, nuke existing dir.
    if old_hash != FONTS_HASH:
        shutil.rmtree(FONTS_DIR, ignore_errors=True)

    if not os.path.exists(hash_file):
        # Download & unpack the archive.
        tar = f'fonts-{FONTS_HASH}.tar.xz'
        uri = '/'.join((FONTS_BASE_URI, tar))
        output = nassh.LIBAPPS_DIR / tar
        libdot.fetch(uri, output)
        libdot.unpack(output, cwd=nassh.DIR)
        libdot.unlink(output)

        # Mark the hash of this checkout.
        with open(hash_file, 'w', encoding='utf-8') as fp:
            fp.write(FONTS_HASH)


def get_parser():
    """Get a command line parser."""
    parser = libdot.ArgumentParser(description=__doc__)
    return parser


def main(argv):
    """The main func!"""
    parser = get_parser()
    _opts = parser.parse_args(argv)

    fonts_update()


if __name__ == '__main__':
    sys.exit(main(sys.argv[1:]))