#!/usr/bin/env python3
#
# Copyright (C) 2018-2020 VyOS maintainers and contributors
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License version 2 or later as
# published by the Free Software Foundation.
#
# 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import os

from copy import deepcopy
from pwd import getpwnam
from socket import gethostname
from sys import exit
from urllib3 import PoolManager

from vyos.config import Config
from vyos.template import render
from vyos.util import call
from vyos import ConfigError

config_file = r'/etc/salt/minion'

default_config_data = {
    'hash_type': 'sha256',
    'log_file': '/var/log/salt/minion',
    'log_level': 'warning',
    'master' : 'salt',
    'user': 'nobody',
    'salt_id': gethostname(),
    'mine_interval': '60',
    'verify_master_pubkey_sign': 'false'
}

def get_config():
    salt = deepcopy(default_config_data)
    conf = Config()
    if not conf.exists('service salt-minion'):
        return None
    else:
        conf.set_level('service salt-minion')

    if conf.exists('hash_type'):
        salt['hash_type'] = conf.return_value('hash_type')

    if conf.exists('log_file'):
        salt['log_file'] = conf.return_value('log_file')

    if conf.exists('log_level'):
        salt['log_level'] = conf.return_value('log_level')

    if conf.exists('master'):
        master = conf.return_values('master')
        salt['master'] = master

    if conf.exists('id'):
        salt['salt_id'] = conf.return_value('id')

    if conf.exists('user'):
        salt['user'] = conf.return_value('user')

    if conf.exists('mine_interval'):
        salt['mine_interval'] = conf.return_value('mine_interval')

    salt['master-key'] = None
    if conf.exists('master-key'):
        salt['master-key'] = conf.return_value('master-key')
        salt['verify_master_pubkey_sign'] = 'true'

    return salt

def verify(salt):
    if not salt:
        return None

    if not salt['salt_id']:
        raise ConfigError('Missing mandatory salt id!')

    if not salt['master']:
        raise ConfigError('Salt master must be defined!')

    return None

def generate(salt):
    if not salt:
        return None

    paths = ['/etc/salt/','/var/run/salt','/opt/vyatta/etc/config/salt/']
    directory = '/opt/vyatta/etc/config/salt/pki/minion'
    uid = getpwnam(salt['user']).pw_uid
    http = PoolManager()

    if not os.path.exists(directory):
        os.makedirs(directory)

    render(config_file, 'salt-minion/minion.tmpl', salt)

    path = "/etc/salt/"
    for path in paths:
      for root, dirs, files in os.walk(path):
        for usgr in dirs:
          os.chown(os.path.join(root, usgr), uid, 100)
        for usgr in files:
          os.chown(os.path.join(root, usgr), uid, 100)

    if not os.path.exists('/opt/vyatta/etc/config/salt/pki/minion/master_sign.pub'):
        if not salt['master-key'] is None:
            r = http.request('GET', salt['master-key'], preload_content=False)

            with open('/opt/vyatta/etc/config/salt/pki/minion/master_sign.pub', 'wb') as out:
                while True:
                    data = r.read(1024)
                    if not data:
                        break
                    out.write(data)

            r.release_conn()

    return None

def apply(salt):
    if salt is not None:
        call('systemctl restart salt-minion.service')
    else:
        # Salt access is removed in the commit
        call('systemctl stop salt-minion.service')
        os.unlink(config_file)

    return None

if __name__ == '__main__':
    try:
        c = get_config()
        verify(c)
        generate(c)
        apply(c)
    except ConfigError as e:
        print(e)
        exit(1)