# yamlconfig.py
#
# Copyright (c) 2008 Trevor Caira
# 
# Permission is hereby granted, free of charge, to any person obtaining
# a copy of this software and associated documentation files (the
# "Software"), to deal in the Software without restriction, including
# without limitation the rights to use, copy, modify, merge, publish,
# distribute, sublicense, and/or sell copies of the Software, and to
# permit persons to whom the Software is furnished to do so, subject to
# the following conditions:
# 
# The above copyright notice and this permission notice shall be
# included in all copies or substantial portions of the Software.
# 
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
# IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
# CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
# TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
# SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

from gettext import gettext as _
import os

class ConfigurationError(KeyError):
    pass

class YamlConfig(dict):
    def __init__(self, options, args):
        import yaml
        if not os.path.exists(options.config):
            self.make_empty_config(options.config)
        f = open(options.config)
        try:
            d = yaml.load(f)
            if d is None:
                d = {}
            super(YamlConfig, self).__init__(d)
        finally:
            f.close()

    def __getitem__(self, k):
        try:
            return super(YamlConfig, self).__getitem__(k)
        except KeyError:
            raise ConfigurationError(_('configuration item "%(key)s" must \
be specified on the command line or in the configuration file') % {
    'key': k})

    def make_empty_config(self, config):
        if not os.path.exists(os.path.dirname(config)):
            os.makedirs(os.path.dirname(config))
        open(config, 'w').close()