import urlparse

class OAuthConfig(object):
  def __init__(self, app, key_name):
    self.key_name = key_name
    self.config = app.config.get(key_name, {})

  def service_name(self):
    raise NotImplementedError

  def token_endpoint(self):
    raise NotImplementedError

  def user_endpoint(self):
    raise NotImplementedError

  def login_endpoint(self):
    raise NotImplementedError

  def client_id(self):
    return self.config.get('CLIENT_ID')

  def client_secret(self):
    return self.config.get('CLIENT_SECRET')

  def _get_url(self, endpoint, *args):
    if not endpoint:
      raise Exception('Missing endpoint configuration for OAuth config %s', self.key_name)

    for arg in args:
      endpoint = urlparse.urljoin(endpoint, arg)

    return endpoint


class GithubOAuthConfig(OAuthConfig):
  def __init__(self, app, key_name):
    super(GithubOAuthConfig, self).__init__(app, key_name)

  def service_name(self):
    return 'GitHub'

  def authorize_endpoint(self):
    endpoint = self.config.get('GITHUB_ENDPOINT')
    return self._get_url(endpoint, '/login/oauth/authorize')  + '?'

  def token_endpoint(self):
    endpoint = self.config.get('GITHUB_ENDPOINT')
    return self._get_url(endpoint, '/login/oauth/access_token')

  def _api_endpoint(self):
    endpoint = self.config.get('GITHUB_ENDPOINT')
    return self.config.get('API_ENDPOINT', self._get_url(endpoint, '/api/v3/'))

  def user_endpoint(self):
    api_endpoint = self._api_endpoint()
    return self._get_url(api_endpoint, 'user')

  def email_endpoint(self):
    api_endpoint = self._api_endpoint()
    return self._get_url(api_endpoint, 'user/emails')


class GoogleOAuthConfig(OAuthConfig):
  def __init__(self, app, key_name):
    super(GoogleOAuthConfig, self).__init__(app, key_name)

  def service_name(self):
    return 'Google'

  def authorize_endpoint(self):
    return 'https://accounts.google.com/o/oauth2/auth?response_type=code&'

  def token_endpoint(self):
    return 'https://accounts.google.com/o/oauth2/token'

  def user_endpoint(self):
    return 'https://www.googleapis.com/oauth2/v1/userinfo'