# Copyright (C) 2014 Rackspace, US Inc.
#
# Author: Nate House <nathan.house@rackspace.com>
#
# This file is part of cloud-init. See LICENSE file for license information.

from cloudinit import distros
from cloudinit import helpers
from cloudinit import log as logging
from cloudinit import util
from cloudinit import subp

from cloudinit.distros import net_util
from cloudinit.distros.parsers.hostname import HostnameConf

from cloudinit.net.renderers import RendererNotFoundError

from cloudinit.settings import PER_INSTANCE

import os

LOG = logging.getLogger(__name__)


class Distro(distros.Distro):
    locale_gen_fn = "/etc/locale.gen"
    network_conf_dir = "/etc/netctl"
    resolve_conf_fn = "/etc/resolv.conf"
    init_cmd = ['systemctl']  # init scripts
    renderer_configs = {
        "netplan": {"netplan_path": "/etc/netplan/50-cloud-init.yaml",
                    "netplan_header": "# generated by cloud-init\n",
                    "postcmds": True}
    }

    def __init__(self, name, cfg, paths):
        distros.Distro.__init__(self, name, cfg, paths)
        # This will be used to restrict certain
        # calls from repeatly happening (when they
        # should only happen say once per instance...)
        self._runner = helpers.Runners(paths)
        self.osfamily = 'arch'
        cfg['ssh_svcname'] = 'sshd'

    def apply_locale(self, locale, out_fn=None):
        if out_fn is not None and out_fn != "/etc/locale.conf":
            LOG.warning("Invalid locale_configfile %s, only supported "
                        "value is /etc/locale.conf", out_fn)
        lines = [
            util.make_header(),
            # Hard-coding the charset isn't ideal, but there is no other way.
            '%s UTF-8' % (locale),
            "",
        ]
        util.write_file(self.locale_gen_fn, "\n".join(lines))
        subp.subp(['locale-gen'], capture=False)
        # In the future systemd can handle locale-gen stuff:
        # https://github.com/systemd/systemd/pull/9864
        subp.subp(['localectl', 'set-locale', locale], capture=False)

    def install_packages(self, pkglist):
        self.update_package_sources()
        self.package_command('', pkgs=pkglist)

    def _write_network_config(self, netconfig):
        try:
            return self._supported_write_network_config(netconfig)
        except RendererNotFoundError as e:
            # Fall back to old _write_network
            raise NotImplementedError from e

    def _write_network(self, settings):
        entries = net_util.translate_network(settings)
        LOG.debug("Translated ubuntu style network settings %s into %s",
                  settings, entries)
        return _render_network(
            entries, resolv_conf=self.resolve_conf_fn,
            conf_dir=self.network_conf_dir,
            enable_func=self._enable_interface)

    def _enable_interface(self, device_name):
        cmd = ['netctl', 'reenable', device_name]
        try:
            (_out, err) = subp.subp(cmd)
            if len(err):
                LOG.warning("Running %s resulted in stderr output: %s",
                            cmd, err)
        except subp.ProcessExecutionError:
            util.logexc(LOG, "Running interface command %s failed", cmd)

    def _bring_up_interface(self, device_name):
        cmd = ['netctl', 'restart', device_name]
        LOG.debug("Attempting to run bring up interface %s using command %s",
                  device_name, cmd)
        try:
            (_out, err) = subp.subp(cmd)
            if len(err):
                LOG.warning("Running %s resulted in stderr output: %s",
                            cmd, err)
            return True
        except subp.ProcessExecutionError:
            util.logexc(LOG, "Running interface command %s failed", cmd)
            return False

    def _bring_up_interfaces(self, device_names):
        for d in device_names:
            if not self._bring_up_interface(d):
                return False
        return True

    def _write_hostname(self, your_hostname, out_fn):
        conf = None
        try:
            # Try to update the previous one
            # so lets see if we can read it first.
            conf = self._read_hostname_conf(out_fn)
        except IOError:
            pass
        if not conf:
            conf = HostnameConf('')
        conf.set_hostname(your_hostname)
        util.write_file(out_fn, str(conf), omode="w", mode=0o644)

    def _read_system_hostname(self):
        sys_hostname = self._read_hostname(self.hostname_conf_fn)
        return (self.hostname_conf_fn, sys_hostname)

    def _read_hostname_conf(self, filename):
        conf = HostnameConf(util.load_file(filename))
        conf.parse()
        return conf

    def _read_hostname(self, filename, default=None):
        hostname = None
        try:
            conf = self._read_hostname_conf(filename)
            hostname = conf.hostname
        except IOError:
            pass
        if not hostname:
            return default
        return hostname

    # hostname (inetutils) isn't installed per default on arch, so we use
    # hostnamectl which is installed per default (systemd).
    def _apply_hostname(self, hostname):
        LOG.debug("Non-persistently setting the system hostname to %s",
                  hostname)
        try:
            subp.subp(['hostnamectl', '--transient', 'set-hostname', hostname])
        except subp.ProcessExecutionError:
            util.logexc(LOG, "Failed to non-persistently adjust the system "
                        "hostname to %s", hostname)

    def set_timezone(self, tz):
        distros.set_etc_timezone(tz=tz, tz_file=self._find_tz_file(tz))

    def package_command(self, command, args=None, pkgs=None):
        if pkgs is None:
            pkgs = []

        cmd = ['pacman', "-Sy", "--quiet", "--noconfirm"]
        # Redirect output

        if args and isinstance(args, str):
            cmd.append(args)
        elif args and isinstance(args, list):
            cmd.extend(args)

        if command == "upgrade":
            command = "-u"
        if command:
            cmd.append(command)

        pkglist = util.expand_package_list('%s-%s', pkgs)
        cmd.extend(pkglist)

        # Allow the output of this to flow outwards (ie not be captured)
        subp.subp(cmd, capture=False)

    def update_package_sources(self):
        self._runner.run("update-sources", self.package_command,
                         ["-y"], freq=PER_INSTANCE)


def _render_network(entries, target="/", conf_dir="etc/netctl",
                    resolv_conf="etc/resolv.conf", enable_func=None):
    """Render the translate_network format into netctl files in target.
    Paths will be rendered under target.
    """

    devs = []
    nameservers = []
    resolv_conf = subp.target_path(target, resolv_conf)
    conf_dir = subp.target_path(target, conf_dir)

    for (dev, info) in entries.items():
        if dev == 'lo':
            # no configuration should be rendered for 'lo'
            continue
        devs.append(dev)
        net_fn = os.path.join(conf_dir, dev)
        net_cfg = {
            'Connection': 'ethernet',
            'Interface': dev,
            'IP': info.get('bootproto'),
            'Address': "%s/%s" % (info.get('address'),
                                  info.get('netmask')),
            'Gateway': info.get('gateway'),
            'DNS': info.get('dns-nameservers', []),
        }
        util.write_file(net_fn, convert_netctl(net_cfg))
        if enable_func and info.get('auto'):
            enable_func(dev)
        if 'dns-nameservers' in info:
            nameservers.extend(info['dns-nameservers'])

    if nameservers:
        util.write_file(resolv_conf,
                        convert_resolv_conf(nameservers))
    return devs


def convert_netctl(settings):
    """Given a dictionary, returns a string in netctl profile format.

    netctl profile is described at:
    https://git.archlinux.org/netctl.git/tree/docs/netctl.profile.5.txt

    Note that the 'Special Quoting Rules' are not handled here."""
    result = []
    for key in sorted(settings):
        val = settings[key]
        if val is None:
            val = ""
        elif isinstance(val, (tuple, list)):
            val = "(" + ' '.join("'%s'" % v for v in val) + ")"
        result.append("%s=%s\n" % (key, val))
    return ''.join(result)


def convert_resolv_conf(settings):
    """Returns a settings string formatted for resolv.conf."""
    result = ''
    if isinstance(settings, list):
        for ns in settings:
            result = result + 'nameserver %s\n' % ns
    return result

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