def add_twitter_login_from_settings(config, prefix="velruse.twitter."):
    settings = config.registry.settings
    p = ProviderSettings(settings, prefix)
    p.update("consumer_key", required=True)
    p.update("consumer_secret", required=True)
    p.update("login_path")
    p.update("callback_path")
    config.add_twitter_login(**p.kwargs)

def add_yandex_login_from_settings(config, prefix='velruse.yandex.'):
    settings = config.registry.settings
    p = ProviderSettings(settings, prefix)
    p.update('consumer_key', required=True)
    p.update('consumer_secret', required=True)
    p.update('login_path')
    p.update('callback_path')
    config.add_yandex_login(**p.kwargs)

def add_openid_from_settings(config, prefix='velruse.openid.'):
    from velruse.settings import ProviderSettings
    settings = config.registry.settings
    p = ProviderSettings(settings, prefix)
    p.update('realm')
    p.update('storage')
    p.update('login_path')
    p.update('callback_path')
    config.add_openid_login(**p.kwargs)

def add_github_login_from_settings(config, prefix='velruse.github.'):
    settings = config.registry.settings
    p = ProviderSettings(settings, prefix)
    p.update('consumer_key', required=True)
    p.update('consumer_secret', required=True)
    p.update('scope')
    p.update('login_path')
    p.update('callback_path')
    p.update('secure')
    p.update('domain')
    config.add_github_login(**p.kwargs)

def add_yasso_login_from_settings(config, prefix):
    settings = config.registry.settings
    p = ProviderSettings(settings, prefix)
    p.update('authorize_url', required=True)
    p.update('token_url', required=True)
    p.update('userinfo_url', required=True)
    p.update('client_id', required=True)
    p.update('client_secret', required=True)
    p.update('login_path')
    p.update('callback_path')
    p.update('name')
    config.add_yasso_login(**p.kwargs)

def add_google_oauth2_login_from_settings(config, prefix='velruse.google.'):
    settings = config.registry.settings
    p = ProviderSettings(settings, prefix)
    if settings.get(prefix + 'protocol') == 'oauth2':
        p.update('consumer_key', required=True)
        p.update('consumer_secret', required=True)
        p.update('scope')
        p.update('login_path')
        p.update('callback_path')
        config.add_google_login(protocol='oauth2', **p.kwargs)

def add_google_login_from_settings(config, prefix='velruse.google.'):
    settings = config.registry.settings
    protocol = settings.get(prefix + 'protocol', 'hybrid')
    if protocol == 'oauth2':
        p = ProviderSettings(settings, prefix)
        p.update('consumer_key', required=True)
        p.update('consumer_secret', required=True)
        p.update('scope')
        p.update('login_path')
        p.update('callback_path')
        config.add_google_login(protocol='oauth2', **p.kwargs)
    else:
        raise ValueError('cannot automatically load google provider from '
                         'settings, unsupported protocol')