# vi: ts=4 expandtab
#
#    Copyright (C) 2014 Harm Weites
#
#    Author: Harm Weites <harm@weites.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
import six
from six import StringIO

import re

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

from cloudinit.distros import net_util
from cloudinit.distros.parsers.resolv_conf import ResolvConf

from cloudinit.settings import PER_INSTANCE

LOG = logging.getLogger(__name__)


class Distro(distros.Distro):
    rc_conf_fn = "/etc/rc.conf"
    login_conf_fn = '/etc/login.conf'
    login_conf_fn_bak = '/etc/login.conf.orig'
    resolv_conf_fn = '/etc/resolv.conf'
    ci_sudoers_fn = '/usr/local/etc/sudoers.d/90-cloud-init-users'

    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 = 'freebsd'

    # Updates a key in /etc/rc.conf.
    def updatercconf(self, key, value):
        LOG.debug("Checking %s for: %s = %s", self.rc_conf_fn, key, value)
        conf = self.loadrcconf()
        config_changed = False
        if key not in conf:
            LOG.debug("Adding key in %s: %s = %s", self.rc_conf_fn, key,
                      value)
            conf[key] = value
            config_changed = True
        else:
            for item in conf.keys():
                if item == key and conf[item] != value:
                    conf[item] = value
                    LOG.debug("Changing key in %s: %s = %s", self.rc_conf_fn,
                              key, value)
                    config_changed = True

        if config_changed:
            LOG.info("Writing %s", self.rc_conf_fn)
            buf = StringIO()
            for keyval in conf.items():
                buf.write('%s="%s"\n' % keyval)
            util.write_file(self.rc_conf_fn, buf.getvalue())

    # Load the contents of /etc/rc.conf and store all keys in a dict. Make sure
    # quotes are ignored:
    #  hostname="bla"
    def loadrcconf(self):
        RE_MATCH = re.compile(r'^(\w+)\s*=\s*(.*)\s*')
        conf = {}
        lines = util.load_file(self.rc_conf_fn).splitlines()
        for line in lines:
            m = RE_MATCH.match(line)
            if not m:
                LOG.debug("Skipping line from /etc/rc.conf: %s", line)
                continue
            key = m.group(1).rstrip()
            val = m.group(2).rstrip()
            # Kill them quotes (not completely correct, aka won't handle
            # quoted values, but should be ok ...)
            if val[0] in ('"', "'"):
                val = val[1:]
            if val[-1] in ('"', "'"):
                val = val[0:-1]
            if len(val) == 0:
                LOG.debug("Skipping empty value from /etc/rc.conf: %s", line)
                continue
            conf[key] = val
        return conf

    def readrcconf(self, key):
        conf = self.loadrcconf()
        try:
            val = conf[key]
        except KeyError:
            val = None
        return val

    # NOVA will inject something like eth0, rewrite that to use the FreeBSD
    # adapter. Since this adapter is based on the used driver, we need to
    # figure out which interfaces are available. On KVM platforms this is
    # vtnet0, where Xen would use xn0.
    def getnetifname(self, dev):
        LOG.debug("Translating network interface %s", dev)
        if dev.startswith('lo'):
            return dev

        n = re.search('\d+$', dev)
        index = n.group(0)

        (out, err) = util.subp(['ifconfig', '-a'])
        ifconfigoutput = [x for x in (out.strip()).splitlines()
                          if len(x.split()) > 0]
        for line in ifconfigoutput:
            m = re.match('^\w+', line)
            if m:
                if m.group(0).startswith('lo'):
                    continue
                # Just settle with the first non-lo adapter we find, since it's
                # rather unlikely there will be multiple nicdrivers involved.
                bsddev = m.group(0)
                break

        # Replace the index with the one we're after.
        bsddev = re.sub('\d+$', index, bsddev)
        LOG.debug("Using network interface %s", bsddev)
        return bsddev

    def _read_system_hostname(self):
        sys_hostname = self._read_hostname(filename=None)
        return ('rc.conf', sys_hostname)

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

    def _write_hostname(self, hostname, filename):
        self.updatercconf('hostname', hostname)

    def create_group(self, name, members):
        group_add_cmd = ['pw', '-n', name]
        if util.is_group(name):
            LOG.warn("Skipping creation of existing group '%s'", name)
        else:
            try:
                util.subp(group_add_cmd)
                LOG.info("Created new group %s", name)
            except Exception as e:
                util.logexc(LOG, "Failed to create group %s", name)
                raise e

        if len(members) > 0:
            for member in members:
                if not util.is_user(member):
                    LOG.warn("Unable to add group member '%s' to group '%s'"
                             "; user does not exist.", member, name)
                    continue
                try:
                    util.subp(['pw', 'usermod', '-n', name, '-G', member])
                    LOG.info("Added user '%s' to group '%s'", member, name)
                except Exception:
                    util.logexc(LOG, "Failed to add user '%s' to group '%s'",
                                member, name)

    def add_user(self, name, **kwargs):
        if util.is_user(name):
            LOG.info("User %s already exists, skipping.", name)
            return False

        adduser_cmd = ['pw', 'useradd', '-n', name]
        log_adduser_cmd = ['pw', 'useradd', '-n', name]

        adduser_opts = {
            "homedir": '-d',
            "gecos": '-c',
            "primary_group": '-g',
            "groups": '-G',
            "passwd": '-h',
            "shell": '-s',
            "inactive": '-E',
        }
        adduser_flags = {
            "no_user_group": '--no-user-group',
            "system": '--system',
            "no_log_init": '--no-log-init',
        }

        redact_opts = ['passwd']

        for key, val in kwargs.items():
            if (key in adduser_opts and val and
               isinstance(val, six.string_types)):
                adduser_cmd.extend([adduser_opts[key], val])

                # Redact certain fields from the logs
                if key in redact_opts:
                    log_adduser_cmd.extend([adduser_opts[key], 'REDACTED'])
                else:
                    log_adduser_cmd.extend([adduser_opts[key], val])

            elif key in adduser_flags and val:
                adduser_cmd.append(adduser_flags[key])
                log_adduser_cmd.append(adduser_flags[key])

        if 'no_create_home' in kwargs or 'system' in kwargs:
            adduser_cmd.append('-d/nonexistent')
            log_adduser_cmd.append('-d/nonexistent')
        else:
            adduser_cmd.append('-d/usr/home/%s' % name)
            adduser_cmd.append('-m')
            log_adduser_cmd.append('-d/usr/home/%s' % name)
            log_adduser_cmd.append('-m')

        # Run the command
        LOG.info("Adding user %s", name)
        try:
            util.subp(adduser_cmd, logstring=log_adduser_cmd)
        except Exception as e:
            util.logexc(LOG, "Failed to create user %s", name)
            raise e

    def set_passwd(self, user, passwd, hashed=False):
        cmd = ['pw', 'usermod', user]

        if hashed:
            cmd.append('-H')
        else:
            cmd.append('-h')

        cmd.append('0')

        try:
            util.subp(cmd, passwd, logstring="chpasswd for %s" % user)
        except Exception as e:
            util.logexc(LOG, "Failed to set password for %s", user)
            raise e

    def lock_passwd(self, name):
        try:
            util.subp(['pw', 'usermod', name, '-h', '-'])
        except Exception as e:
            util.logexc(LOG, "Failed to lock user %s", name)
            raise e

    def create_user(self, name, **kwargs):
        self.add_user(name, **kwargs)

        # Set password if plain-text password provided and non-empty
        if 'plain_text_passwd' in kwargs and kwargs['plain_text_passwd']:
            self.set_passwd(name, kwargs['plain_text_passwd'])

        # Default locking down the account. 'lock_passwd' defaults to True.
        # lock account unless lock_password is False.
        if kwargs.get('lock_passwd', True):
            self.lock_passwd(name)

        # Configure sudo access
        if 'sudo' in kwargs:
            self.write_sudo_rules(name, kwargs['sudo'])

        # Import SSH keys
        if 'ssh_authorized_keys' in kwargs:
            keys = set(kwargs['ssh_authorized_keys']) or []
            ssh_util.setup_user_keys(keys, name, options=None)

    def _write_network(self, settings):
        entries = net_util.translate_network(settings)
        nameservers = []
        searchdomains = []
        dev_names = entries.keys()
        for (device, info) in entries.items():
            # Skip the loopback interface.
            if device.startswith('lo'):
                continue

            dev = self.getnetifname(device)

            LOG.info('Configuring interface %s', dev)

            if info.get('bootproto') == 'static':
                LOG.debug('Configuring dev %s with %s / %s', dev,
                          info.get('address'), info.get('netmask'))
                # Configure an ipv4 address.
                ifconfig = (info.get('address') + ' netmask ' +
                            info.get('netmask'))

                # Configure the gateway.
                self.updatercconf('defaultrouter', info.get('gateway'))

                if 'dns-nameservers' in info:
                    nameservers.extend(info['dns-nameservers'])
                if 'dns-search' in info:
                    searchdomains.extend(info['dns-search'])
            else:
                ifconfig = 'DHCP'

            self.updatercconf('ifconfig_' + dev, ifconfig)

        # Try to read the /etc/resolv.conf or just start from scratch if that
        # fails.
        try:
            resolvconf = ResolvConf(util.load_file(self.resolv_conf_fn))
            resolvconf.parse()
        except IOError:
            util.logexc(LOG, "Failed to parse %s, use new empty file",
                        self.resolv_conf_fn)
            resolvconf = ResolvConf('')
            resolvconf.parse()

        # Add some nameservers
        for server in nameservers:
            try:
                resolvconf.add_nameserver(server)
            except ValueError:
                util.logexc(LOG, "Failed to add nameserver %s", server)

        # And add any searchdomains.
        for domain in searchdomains:
            try:
                resolvconf.add_search_domain(domain)
            except ValueError:
                util.logexc(LOG, "Failed to add search domain %s", domain)
        util.write_file(self.resolv_conf_fn, str(resolvconf), 0o644)

        return dev_names

    def apply_locale(self, locale, out_fn=None):
        # Adjust the locals value to the new value
        newconf = StringIO()
        for line in util.load_file(self.login_conf_fn).splitlines():
            newconf.write(re.sub(r'^default:',
                                 r'default:lang=%s:' % locale, line))
            newconf.write("\n")

        # Make a backup of login.conf.
        util.copy(self.login_conf_fn, self.login_conf_fn_bak)

        # And write the new login.conf.
        util.write_file(self.login_conf_fn, newconf.getvalue())

        try:
            LOG.debug("Running cap_mkdb for %s", locale)
            util.subp(['cap_mkdb', self.login_conf_fn])
        except util.ProcessExecutionError:
            # cap_mkdb failed, so restore the backup.
            util.logexc(LOG, "Failed to apply locale %s", locale)
            try:
                util.copy(self.login_conf_fn_bak, self.login_conf_fn)
            except IOError:
                util.logexc(LOG, "Failed to restore %s backup",
                            self.login_conf_fn)

    def _bring_up_interface(self, device_name):
        if device_name.startswith('lo'):
            return
        dev = self.getnetifname(device_name)
        cmd = ['/etc/rc.d/netif', 'start', dev]
        LOG.debug("Attempting to bring up interface %s using command %s",
                  dev, cmd)
        # This could return 1 when the interface has already been put UP by the
        # OS. This is just fine.
        (_out, err) = util.subp(cmd, rcs=[0, 1])
        if len(err):
            LOG.warn("Error running %s: %s", cmd, err)

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

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

        e = os.environ.copy()
        e['ASSUME_ALWAYS_YES'] = 'YES'

        cmd = ['pkg']
        if args and isinstance(args, str):
            cmd.append(args)
        elif args and isinstance(args, list):
            cmd.extend(args)

        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)
        util.subp(cmd, env=e, capture=False)

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

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