import ConfigParser


class NovaConfig(object):
    """Provides configuration information for connecting to Nova."""

    def __init__(self, conf):
        """Initialize a Nova-specific configuration object"""
        self.conf = conf

    def get(self, item_name, default_value):
        try:
            return self.conf.get("nova", item_name)
        except (ConfigParser.NoSectionError, ConfigParser.NoOptionError):
            return default_value

    @property
    def auth_url(self):
        """URL used to authenticate. Defaults to 127.0.0.1."""
        return self.get("auth_url", "127.0.0.1")

    @property
    def username(self):
        """Username to use for Nova API requests. Defaults to 'admin'."""
        return self.get("user", "admin")

    @property
    def tenant_name(self):
        """Tenant name to use for Nova API requests. Defaults to 'admin'."""
        return self.get("tenant_name", "admin")

    @property
    def api_key(self):
        """API key to use when authenticating. Defaults to 'admin_key'."""
        return self.get("api_key", "admin_key")

    @property
    def build_interval(self):
        """Time in seconds between build status checks."""
        return float(self.get("build_interval", 10))

    @property
    def ssh_timeout(self):
        """Timeout in seconds to use when connecting via ssh."""
        return float(self.get("ssh_timeout", 300))

    @property
    def build_timeout(self):
        """Timeout in seconds to wait for an entity to build."""
        return float(self.get("build_timeout", 300))


class EnvironmentConfig(object):
    def __init__(self, conf):
        """Initialize a Environment-specific configuration object."""
        self.conf = conf

    def get(self, item_name, default_value):
        try:
            return self.conf.get("environment", item_name)
        except (ConfigParser.NoSectionError, ConfigParser.NoOptionError):
            return default_value

    @property
    def image_ref(self):
        """Valid imageRef to use """
        return self.get("image_ref", 3)

    @property
    def image_ref_alt(self):
        """Valid imageRef to rebuild images with"""
        return self.get("image_ref_alt", 3)

    @property
    def flavor_ref(self):
        """Valid flavorRef to use"""
        return self.get("flavor_ref", 1)

    @property
    def flavor_ref_alt(self):
        """Valid flavorRef to resize images with"""
        return self.get("flavor_ref_alt", 2)

    @property
    def resize_available(self):
        """ Does the test environment support resizing """
        return self.get("resize_available", 'false') != 'false'

    @property
    def create_image_enabled(self):
        """ Does the test environment support resizing """
        return self.get("create_image_enabled", 'false') != 'false'

    @property
    def authentication(self):
        """ What auth method does the environment use (basic|keystone) """
        return self.get("authentication", 'keystone')


class StormConfig(object):
    """Provides OpenStack configuration information."""

    _path = "etc/storm.conf"

    def __init__(self, path=None):
        """Initialize a configuration from a path."""
        self._conf = self.load_config(self._path)
        self.nova = NovaConfig(self._conf)
        self.env = EnvironmentConfig(self._conf)

    def load_config(self, path=None):
        """Read configuration from given path and return a config object."""
        config = ConfigParser.SafeConfigParser()
        config.read(path)
        return config