# vi: ts=4 expandtab
#
#    Copyright (C) 2011 Canonical Ltd.
#    Copyright (C) 2012 Hewlett-Packard Development Company, L.P.
#
#    Author: Scott Moser <scott.moser@canonical.com>
#    Author: Juerg Haefliger <juerg.haefliger@hp.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 StringIO import StringIO

try:
    from configobj import ConfigObj
except ImportError:
    ConfigObj = None

from cloudinit import util

from cloudinit.settings import PER_INSTANCE

frequency = PER_INSTANCE

lsc_client_cfg_file = "/etc/landscape/client.conf"

distros = ['ubuntu']

# defaults taken from stock client.conf in landscape-client 11.07.1.1-0ubuntu2
lsc_builtincfg = {
  'client': {
    'log_level': "info",
    'url': "https://landscape.canonical.com/message-system",
    'ping_url': "http://landscape.canonical.com/ping",
    'data_path': "/var/lib/landscape/client",
  }
}


def handle(name, cfg, _cloud, log, _args):
    """
    Basically turn a top level 'landscape' entry with a 'client' dict
    and render it to ConfigObj format under '[client]' section in
    /etc/landscape/client.conf
    """
    if not ConfigObj:
        log.warn(("'ConfigObj' support not available,"
                  " running transform %s disabled"), name)
        return

    ls_cloudcfg = cfg.get("landscape", {})

    if not isinstance(ls_cloudcfg, dict):
        raise Exception(("'landscape' key existed in config," 
                         " but not a dictionary type,"
                         " is a %s instead"), util.obj_name(ls_cloudcfg))

    merged = merge_together([lsc_builtincfg, lsc_client_cfg_file, ls_cloudcfg])

    if not os.path.isdir(os.path.dirname(lsc_client_cfg_file)):
        util.ensure_dir(os.path.dirname(lsc_client_cfg_file))

    contents = StringIO()
    merged.write(contents)
    util.write_file(lsc_client_cfg_file, contents.getvalue())
    log.debug("Wrote landscape config file to %s", lsc_client_cfg_file)


def merge_together(objs):
    """
    merge together ConfigObj objects or things that ConfigObj() will take in
    later entries override earlier
    """
    cfg = ConfigObj({})
    for obj in objs:
        if not obj:
            continue
        if isinstance(obj, ConfigObj):
            cfg.merge(obj)
        else:
            cfg.merge(ConfigObj(obj))
    return cfg