def token(token_req):
"""
handler to convert a code into an authorization token
token_req provided by validate_token_request decorator
once neuaer recieves the code provided in the authorize method it will
contact the app here where the code can be 'redeemed' for an authorization
token
"""
# get the stored authorization using the code and request uri
auth = Authorization.get_with_auth(code=token_req.raw_args.get('code'),
uri=token_req.raw_args.get('redirect_uri'))
# if there were no matches report
if not auth:
return jsonify(**token_error_responses('no_match'))
# if the access token has already been granted for this uri and code
if auth.access_token:
return jsonify(**token_error_responses('already_granted'))
# return the access token to the requester
return jsonify(access_token=auth.generate_token())
