text: # -*- coding: utf-8 -*-
  """
  oauthlib.oauth2.rfc6749
  ~~~~~~~~~~~~~~~~~~~~~~~
  
  This module is an implementation of various logic needed
  for consuming and providing OAuth 2.0 RFC6749.
  """
  from __future__ import absolute_import, unicode_literals
  
  from ..parameters import parse_token_response, prepare_token_request
  from .base import Client
  
  
  class LegacyApplicationClient(Client):
  
      """A public client using the resource owner password and username directly.
  
      The resource owner password credentials grant type is suitable in
      cases where the resource owner has a trust relationship with the
      client, such as the device operating system or a highly privileged
      application.  The authorization server should take special care when
      enabling this grant type, and only allow it when other flows are not
      viable.
  
      The grant type is suitable for clients capable of obtaining the
      resource owner's credentials (username and password, typically using
      an interactive form).  It is also used to migrate existing clients
      using direct authentication schemes such as HTTP Basic or Digest
      authentication to OAuth by converting the stored credentials to an
      access token.
  
      The method through which the client obtains the resource owner
      credentials is beyond the scope of this specification.  The client
      MUST discard the credentials once an access token has been obtained.
      """
  
      def __init__(self, client_id, **kwargs):
          super(LegacyApplicationClient, self).__init__(client_id, **kwargs)
  
      def prepare_request_body(self, username, password, body='', scope=None, **kwargs):
          """Add the resource owner password and username to the request body.
  
          The client makes a request to the token endpoint by adding the
          following parameters using the "application/x-www-form-urlencoded"
          format per `Appendix B`_ in the HTTP request entity-body:
  
          :param username:    The resource owner username.
          :param password:    The resource owner password.
          :param scope:   The scope of the access request as described by
                          `Section 3.3`_.
          :param kwargs:  Extra credentials to include in the token request.
  
          If the client type is confidential or the client was issued client
          credentials (or assigned other authentication requirements), the
          client MUST authenticate with the authorization server as described
          in `Section 3.2.1`_.
  
          The prepared body will include all provided credentials as well as
          the ``grant_type`` parameter set to ``password``::
  
              >>> from oauthlib.oauth2 import LegacyApplicationClient
              >>> client = LegacyApplicationClient('your_id')
              >>> client.prepare_request_body(username='foo', password='bar', scope=['hello', 'world'])
              'grant_type=password&username=foo&scope=hello+world&password=bar'
  
          .. _`Appendix B`: http://tools.ietf.org/html/rfc6749#appendix-B
          .. _`Section 3.3`: http://tools.ietf.org/html/rfc6749#section-3.3
          .. _`Section 3.2.1`: http://tools.ietf.org/html/rfc6749#section-3.2.1
          """
          return prepare_token_request('password', body=body, username=username,
                                       password=password, scope=scope, **kwargs)
  