# 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 logging
import os
import os.path
import typing
from ipaddress import IPv4Address

from cloudinit import sources, subp, util
from cloudinit.event import EventScope, 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 increment_ip(addr, inc: int) -> str:
    return str(IPv4Address(int(IPv4Address(addr)) + inc))


def get_three_ips(addr) -> typing.List[str]:
    """Return a list of 3 IP addresses: [addr, addr + 2, addr + 3]

    @param addr: an object that is passed to IPvAddress
    @return: list of strings
    """
    return [
        addr,
        increment_ip(addr, 2),
        increment_ip(addr, 3),
    ]


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():
    """Returns False (not found or error) or a dictionary with metadata."""
    devices = set(
        util.find_devs_with("LABEL=CLOUDMD")
        + util.find_devs_with("LABEL=cloudmd")
    )
    if not devices:
        return False
    for device in devices:
        try:
            rbx_data = util.mount_cb(
                device=device,
                callback=read_user_data_callback,
                mtype=["vfat", "fat", "msdosfs"],
            )
            if rbx_data:
                return rbx_data
        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
            )

    LOG.debug(
        "Did not find RbxCloud data, searched devices: %s", ",".join(devices)
    )
    return False


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 get_three_ips(netadp["network"]["gateway"])
        ],
        "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"
    default_update_events = {
        EventScope.NETWORK: {
            EventType.BOOT_NEW_INSTANCE,
            EventType.BOOT,
            EventType.BOOT_LEGACY,
        }
    }

    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()
        if rbx_data is False:
            return False
        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)
