# vi: ts=4 expandtab
#
#    Copyright (C) 2012 Canonical Ltd.
#    Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
#    Copyright (C) 2012 Yahoo! Inc.
#
#    Author: Scott Moser <scott.moser@canonical.com>
#    Author: Juerg Haefliger <juerg.haefliger@hp.com>
#    Author: Joshua Harlow <harlowja@yahoo-inc.com>
#
#    This program is free software: you can redistribute it and/or modify
#    it under the terms of the GNU General Public License version 3, 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 cloudinit import distros
from cloudinit import helpers
from cloudinit import log as logging
from cloudinit import util
from cloudinit import net

from cloudinit.distros.parsers.hostname import HostnameConf

from cloudinit.settings import PER_INSTANCE

LOG = logging.getLogger(__name__)

APT_GET_COMMAND = ('apt-get', '--option=Dpkg::Options::=--force-confold',
                   '--option=Dpkg::options::=--force-unsafe-io',
                   '--assume-yes', '--quiet')
APT_GET_WRAPPER = {
    'command': 'eatmydata',
    'enabled': 'auto',
}


class Distro(distros.Distro):
    hostname_conf_fn = "/etc/hostname"
    locale_conf_fn = "/etc/default/locale"
    network_conf_fn = "/etc/network/interfaces.d/50-cloud-init.cfg"
    links_prefix = "/etc/systemd/network/50-cloud-init-"

    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 = 'debian'

    def apply_locale(self, locale, out_fn=None):
        if not out_fn:
            out_fn = self.locale_conf_fn
        util.subp(['locale-gen', locale], capture=False)
        util.subp(['update-locale', locale], capture=False)
        # "" provides trailing newline during join
        lines = [
            util.make_header(),
            'LANG="%s"' % (locale),
            "",
        ]
        util.write_file(out_fn, "\n".join(lines))

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

    def _write_network(self, settings):
        util.write_file(self.network_conf_fn, settings)
        return ['all']

    def _write_network_config(self, netconfig):
        ns = net.parse_net_config_data(netconfig)
        net.render_network_state(target="/", network_state=ns,
                                 eni=self.network_conf_fn,
                                 links_prefix=self.links_prefix,
                                 netrules=None)
        _maybe_remove_legacy_eth0()

        return []

    def _bring_up_interfaces(self, device_names):
        use_all = False
        for d in device_names:
            if d == 'all':
                use_all = True
        if use_all:
            return distros.Distro._bring_up_interface(self, '--all')
        else:
            return distros.Distro._bring_up_interfaces(self, device_names)

    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), 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

    def _get_localhost_ip(self):
        # Note: http://www.leonardoborda.com/blog/127-0-1-1-ubuntu-debian/
        return "127.0.1.1"

    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 = []

        e = os.environ.copy()
        # See: http://tiny.cc/kg91fw
        # Or: http://tiny.cc/mh91fw
        e['DEBIAN_FRONTEND'] = 'noninteractive'

        wcfg = self.get_option("apt_get_wrapper", APT_GET_WRAPPER)
        cmd = _get_wrapper_prefix(
            wcfg.get('command', APT_GET_WRAPPER['command']),
            wcfg.get('enabled', APT_GET_WRAPPER['enabled']))

        cmd.extend(list(self.get_option("apt_get_command", APT_GET_COMMAND)))

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

        subcmd = command
        if command == "upgrade":
            subcmd = self.get_option("apt_get_upgrade_subcommand",
                                     "dist-upgrade")

        cmd.append(subcmd)

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

        # Allow the output of this to flow outwards (ie not be captured)
        util.log_time(logfunc=LOG.debug,
                      msg="apt-%s [%s]" % (command, ' '.join(cmd)),
                      func=util.subp,
                      args=(cmd,), kwargs={'env': e, 'capture': False})

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

    def get_primary_arch(self):
        (arch, _err) = util.subp(['dpkg', '--print-architecture'])
        return str(arch).strip()


def _get_wrapper_prefix(cmd, mode):
    if isinstance(cmd, str):
        cmd = [str(cmd)]

    if (util.is_true(mode) or
        (str(mode).lower() == "auto" and cmd[0] and
         util.which(cmd[0]))):
        return cmd
    else:
        return []


def _maybe_remove_legacy_eth0(path="/etc/network/interfaces.d/eth0.cfg"):
    """Ubuntu cloud images previously included a 'eth0.cfg' that had
       hard coded content.  That file would interfere with the rendered
       configuration if it was present.

       if the file does not exist do nothing.
       If the file exists:
         - with known content, remove it and warn
         - with unknown content, leave it and warn
    """

    if not os.path.exists(path):
        return

    bmsg = "Dynamic networking config may not apply."
    try:
        contents = util.load_file(path)
        known_contents = ["auto eth0", "iface eth0 inet dhcp"]
        lines = [f.strip() for f in contents.splitlines()
                 if not f.startswith("#")]
        if lines == known_contents:
            util.del_file(path)
            msg = "removed %s with known contents" % path
        else:
            msg = (bmsg + " '%s' exists with user configured content." % path)
    except:
        msg = bmsg + " %s exists, but could not be read." % path

    LOG.warn(msg)
