import yaml
import os

from .util import pushd


class ConfigException(Exception):
    pass


class BaseConfig(object):
    def __init__(self, path):
        self.path = path
        if not os.path.exists(path):
            raise ConfigException("Base config file not found: {}".format(path))

        with open(path) as f:
            self._data = yaml.load(f, Loader=yaml.SafeLoader)

        self.sources = []
        with pushd(os.path.dirname(path)):
            for source in self["sources"]:
                self.sources.append(RepoConfig(self, source))

    def __getitem__(self, name):
        return self._data[name]

    def __contains__(self, name):
        return name in self._data


class RepoConfig(object):
    def __init__(self, config, path):
        self.path = path
        self.config = config

        if not os.path.exists(path):
            raise ConfigException("Repo config file not found: {}".format(path))

        with open(path) as f:
            self._data = yaml.load(f, Loader=yaml.SafeLoader)

    def __getitem__(self, name):
        return self._data[name]

    def __contains__(self, name):
        return name in self._data