#!/usr/bin/env python3
#
# Copyright (C) 2019-2021 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 sys
import os
import json

from time import sleep
from copy import deepcopy

import vyos.defaults

from vyos.config import Config
from vyos.template import render
from vyos.util import cmd
from vyos.util import call
from vyos import ConfigError
from vyos import airbag
airbag.enable()

api_conf_file = '/etc/vyos/http-api.conf'
systemd_service = '/run/systemd/system/vyos-http-api.service'

vyos_conf_scripts_dir=vyos.defaults.directories['conf_mode']

def get_config(config=None):
    http_api = deepcopy(vyos.defaults.api_data)
    x = http_api.get('api_keys')
    if not x:
        default_key = None
    else:
        default_key = x[0]
    keys_added = False

    if config:
        conf = config
    else:
        conf = Config()

    base = ['service', 'https', 'api']
    if not conf.exists(base):
        return None

    # Do we run inside a VRF context?
    vrf_path = ['service', 'https', 'vrf']
    if conf.exists(vrf_path):
        http_api['vrf'] = conf.return_value(vrf_path)

    conf.set_level('service https api')
    if conf.exists('strict'):
        http_api['strict'] = True

    if conf.exists('debug'):
        http_api['debug'] = True

    # this node is not available by CLI by default, and is reserved for
    # the graphql tools. One can enable it for testing, with the warning
    # that this will open an unauthenticated server. To do so
    # mkdir /opt/vyatta/share/vyatta-cfg/templates/service/https/api/gql
    # touch /opt/vyatta/share/vyatta-cfg/templates/service/https/api/gql/node.def
    # and configure; editing the config alone is insufficient.
    if conf.exists('gql'):
        http_api['gql'] = True

    if conf.exists('socket'):
        http_api['socket'] = True

    if conf.exists('port'):
        port = conf.return_value('port')
        http_api['port'] = port

    if conf.exists('cors'):
        http_api['cors'] = {}
        if conf.exists('cors allow-origin'):
            origins = conf.return_values('cors allow-origin')
            http_api['cors']['origins'] = origins[:]

    if conf.exists('keys'):
        for name in conf.list_nodes('keys id'):
            if conf.exists('keys id {0} key'.format(name)):
                key = conf.return_value('keys id {0} key'.format(name))
                new_key = { 'id': name, 'key': key }
                http_api['api_keys'].append(new_key)
            else:
                raise ConfigError(f'Missing HTTPS API key string for key id "{name}"')

    return http_api

def verify(http_api):
    # Verify API server settings, if present
    keys = http_api['api_keys']

    if not keys:
        raise ConfigError('At least one HTTPS API key is required')

    return None

def generate(http_api):
    if http_api is None:
        if os.path.exists(systemd_service):
            os.unlink(systemd_service)
        return None

    if not os.path.exists('/etc/vyos'):
        os.mkdir('/etc/vyos')

    with open(api_conf_file, 'w') as f:
        json.dump(http_api, f, indent=2)

    render(systemd_service, 'https/vyos-http-api.service.tmpl', http_api)
    return None

def apply(http_api):
    # Reload systemd manager configuration
    call('systemctl daemon-reload')
    service_name = 'vyos-http-api.service'

    if http_api is not None:
        call(f'systemctl restart {service_name}')
    else:
        call(f'systemctl stop {service_name}')

    # Let uvicorn settle before restarting Nginx
    sleep(1)

    cmd(f'{vyos_conf_scripts_dir}/https.py', raising=ConfigError)

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