#!/usr/bin/python3
#
# This file is part of Plinth.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.
#

"""
Configuration helper for monkeysphere.
"""

import argparse
import json
import os
import subprocess


def parse_arguments():
    """Return parsed command line arguments as dictionary."""
    parser = argparse.ArgumentParser()
    subparsers = parser.add_subparsers(dest='subcommand', help='Sub command')

    host_show_keys = subparsers.add_parser(
        'host-show-keys', help='Show host key fingerprints')
    host_show_keys.add_argument(
        'key_ids', nargs='*', help='Optional list of KEYIDs')

    host_import_ssh_key = subparsers.add_parser(
        'host-import-ssh-key', help='Import host SSH key')
    host_import_ssh_key.add_argument(
        'hostname', help='Fully-qualified hostname')

    host_publish_key = subparsers.add_parser(
        'host-publish-key', help='Push host key to keyserver')
    host_publish_key.add_argument(
        'key_ids', nargs='*', help='Optional list of KEYIDs')

    return parser.parse_args()


def subcommand_host_show_keys(arguments):
    """Show host key fingerprints."""
    try:
        output = subprocess.check_output(
            ['monkeysphere-host', 'show-keys'] + arguments.key_ids)
    except subprocess.CalledProcessError:
        # no keys available
        return

    # parse output
    keys = [dict()]
    lines = output.decode().strip().split('\n')
    for line in lines:
        if line.startswith('pub'):
            data = line.lstrip('pub').split()
            keys[-1]['pub'] = data[0]
            keys[-1]['date'] = data[1]
        elif line.startswith('uid'):
            keys[-1]['uid'] = line.lstrip('uid').strip()
        elif line.startswith('OpenPGP fingerprint:'):
            keys[-1]['pgp_fingerprint'] = line.lstrip('Open PGP fingerprint:')
        elif line.startswith('ssh fingerprint:'):
            data = line.lstrip('ssh fingerprint:').split()
            keys[-1]['ssh_key_size'] = data[0]
            keys[-1]['ssh_fingerprint'] = data[1]
            keys[-1]['ssh_key_type'] = data[2].strip('()')
        elif line == '':
            keys.append(dict())

    print(json.dumps({'keys': keys}))


def subcommand_host_import_ssh_key(arguments):
    """Import host SSH key."""
    output = subprocess.check_output(
        ['monkeysphere-host', 'import-key',
         '/etc/ssh/ssh_host_rsa_key', arguments.hostname])
    print(output.decode())


def subcommand_host_publish_key(arguments):
    """Push host key to keyserver."""
    # setting TMPDIR as workaround for Debian bug #656750
    proc = subprocess.Popen(
        ['monkeysphere-host', 'publish-keys'] + arguments.key_ids,
        stdout=subprocess.PIPE, stderr=subprocess.PIPE,
        env=dict(
            os.environ,
            TMPDIR='/var/lib/monkeysphere/authentication/tmp/',
            MONKEYSPHERE_PROMPT='false'))
    output, error = proc.communicate()
    output, error = output.decode(), error.decode()
    if proc.returncode != 0:
        raise Exception(output, error)

    print(output)


def main():
    """Parse arguments and perform all duties."""
    arguments = parse_arguments()

    subcommand = arguments.subcommand.replace('-', '_')
    subcommand_method = globals()['subcommand_' + subcommand]
    subcommand_method(arguments)


if __name__ == '__main__':
    main()