# Copyright (C) 2018 Warsaw Data Center
#
# Author: Malwina Leis <m.leis@rootbox.com>
# Author: Grzegorz Brzeski <gregory@rootbox.io>
# Author: Adam Dobrawy <a.dobrawy@hyperone.com>
#
# This file is part of cloud-init. See LICENSE file for license information.
"""
This file contains code used to gather the user data passed to an
instance on rootbox / hyperone cloud platforms
"""
import errno
import os
import os.path

from cloudinit import log as logging
from cloudinit import sources
from cloudinit import subp
from cloudinit import util
from cloudinit.event import EventType

LOG = logging.getLogger(__name__)
ETC_HOSTS = '/etc/hosts'


def get_manage_etc_hosts():
    hosts = util.load_file(ETC_HOSTS, quiet=True)
    if hosts:
        LOG.debug('/etc/hosts exists - setting manage_etc_hosts to False')
        return False
    LOG.debug('/etc/hosts does not exists - setting manage_etc_hosts to True')
    return True


def ip2int(addr):
    parts = addr.split('.')
    return (int(parts[0]) << 24) + (int(parts[1]) << 16) + \
           (int(parts[2]) << 8) + int(parts[3])


def int2ip(addr):
    return '.'.join([str(addr >> (i << 3) & 0xFF) for i in range(4)[::-1]])


def _sub_arp(cmd):
    """
    Uses the preferred cloud-init subprocess def of subp.subp
    and runs arping.  Breaking this to a separate function
    for later use in mocking and unittests
    """
    return subp.subp(['arping'] + cmd)


def gratuitous_arp(items, distro):
    source_param = '-S'
    if distro.name in ['fedora', 'centos', 'rhel']:
        source_param = '-s'
    for item in items:
        try:
            _sub_arp([
                '-c', '2',
                source_param, item['source'],
                item['destination']
            ])
        except subp.ProcessExecutionError as error:
            # warning, because the system is able to function properly
            # despite no success - some ARP table may be waiting for
            # expiration, but the system may continue
            LOG.warning('Failed to arping from "%s" to "%s": %s',
                        item['source'], item['destination'], error)


def get_md():
    rbx_data = None
    devices = set(
        util.find_devs_with('LABEL=CLOUDMD') +
        util.find_devs_with('LABEL=cloudmd')
    )
    for device in devices:
        try:
            rbx_data = util.mount_cb(
                device=device,
                callback=read_user_data_callback,
                mtype=['vfat', 'fat', 'msdosfs']
            )
            if rbx_data:
                break
        except OSError as err:
            if err.errno != errno.ENOENT:
                raise
        except util.MountFailedError:
            util.logexc(LOG, "Failed to mount %s when looking for user "
                             "data", device)
    if not rbx_data:
        util.logexc(LOG, "Failed to load metadata and userdata")
        return False
    return rbx_data


def generate_network_config(netadps):
    """Generate network configuration

    @param netadps: A list of network adapter settings

    @returns: A dict containing network config
    """
    return {
        'version': 1,
        'config': [
            {
                'type': 'physical',
                'name': 'eth{}'.format(str(i)),
                'mac_address': netadp['macaddress'].lower(),
                'subnets': [
                    {
                        'type': 'static',
                        'address': ip['address'],
                        'netmask': netadp['network']['netmask'],
                        'control': 'auto',
                        'gateway': netadp['network']['gateway'],
                        'dns_nameservers': netadp['network']['dns'][
                            'nameservers']
                    } for ip in netadp['ip']
                ],
            } for i, netadp in enumerate(netadps)
        ]
    }


def read_user_data_callback(mount_dir):
    """This callback will be applied by util.mount_cb() on the mounted
    drive.

    @param mount_dir: String representing path of directory where mounted drive
    is available

    @returns: A dict containing userdata, metadata and cfg based on metadata.
    """
    meta_data = util.load_json(
        text=util.load_file(
            fname=os.path.join(mount_dir, 'cloud.json'),
            decode=False
        )
    )
    user_data = util.load_file(
        fname=os.path.join(mount_dir, 'user.data'),
        quiet=True
    )
    if 'vm' not in meta_data or 'netadp' not in meta_data:
        util.logexc(LOG, "Failed to load metadata. Invalid format.")
        return None
    username = meta_data.get('additionalMetadata', {}).get('username')
    ssh_keys = meta_data.get('additionalMetadata', {}).get('sshKeys', [])

    hash = None
    if meta_data.get('additionalMetadata', {}).get('password'):
        hash = meta_data['additionalMetadata']['password']['sha512']

    network = generate_network_config(meta_data['netadp'])

    data = {
        'userdata': user_data,
        'metadata': {
            'instance-id': meta_data['vm']['_id'],
            'local-hostname': meta_data['vm']['name'],
            'public-keys': []
        },
        'gratuitous_arp': [
            {
                "source": ip["address"],
                "destination": target
            }
            for netadp in meta_data['netadp']
            for ip in netadp['ip']
            for target in [
                netadp['network']["gateway"],
                int2ip(ip2int(netadp['network']["gateway"]) + 2),
                int2ip(ip2int(netadp['network']["gateway"]) + 3)
            ]
        ],
        'cfg': {
            'ssh_pwauth': True,
            'disable_root': True,
            'system_info': {
                'default_user': {
                    'name': username,
                    'gecos': username,
                    'sudo': ['ALL=(ALL) NOPASSWD:ALL'],
                    'passwd': hash,
                    'lock_passwd': False,
                    'ssh_authorized_keys': ssh_keys,
                }
            },
            'network_config': network,
            'manage_etc_hosts': get_manage_etc_hosts(),
        },
    }

    LOG.debug('returning DATA object:')
    LOG.debug(data)

    return data


class DataSourceRbxCloud(sources.DataSource):
    dsname = "RbxCloud"
    update_events = {'network': [
        EventType.BOOT_NEW_INSTANCE,
        EventType.BOOT
    ]}

    def __init__(self, sys_cfg, distro, paths):
        sources.DataSource.__init__(self, sys_cfg, distro, paths)
        self.seed = None

    def __str__(self):
        root = sources.DataSource.__str__(self)
        return "%s [seed=%s]" % (root, self.seed)

    def _get_data(self):
        """
        Metadata is passed to the launching instance which
        is used to perform instance configuration.
        """
        rbx_data = get_md()
        self.userdata_raw = rbx_data['userdata']
        self.metadata = rbx_data['metadata']
        self.gratuitous_arp = rbx_data['gratuitous_arp']
        self.cfg = rbx_data['cfg']
        return True

    @property
    def network_config(self):
        return self.cfg['network_config']

    def get_public_ssh_keys(self):
        return self.metadata['public-keys']

    def get_userdata_raw(self):
        return self.userdata_raw

    def get_config_obj(self):
        return self.cfg

    def activate(self, cfg, is_new_instance):
        gratuitous_arp(self.gratuitous_arp, self.distro)


# Used to match classes to dependencies
datasources = [
    (DataSourceRbxCloud, (sources.DEP_FILESYSTEM,)),
]


# Return a list of data sources that match this set of dependencies
def get_datasource_list(depends):
    return sources.list_from_depends(depends, datasources)
