Start the work on Request middle layer

Author: rayluo

msal/application.py

@@ -1,10 +1,8 @@
-from . import oauth2
-from .exceptions import MsalServiceError
+from . import request
 
 
 class ClientApplication(object):
     DEFAULT_AUTHORITY = "https://login.microsoftonline.com/common/"
-    TOKEN_ENDPOINT_PATH = 'oauth2/v2.0/token'
 
     def __init__(
             self, client_id,
@@ -37,12 +35,7 @@ def __init__(self, client_id, client_credential, user_token_cache, **kwargs):
         self.app_token_cache = None  # TODO
 
     def acquire_token_for_client(self, scope, policy=''):
-        result = oauth2.ClientCredentialGrant(
-            self.client_id,
-            token_endpoint="%s%s?policy=%s" % (
-                self.authority, self.TOKEN_ENDPOINT_PATH, policy),
-            ).get_token(scope=scope, client_secret=self.client_credential)
-        if 'error' in result:
-            raise MsalServiceError(**result)
-        return result
+        return request.ClientCredentialRequest(
+            client_id=self.client_id, client_credential=self.client_credential,
+            scope=scope, policy=policy, authority=self.authority).run()
 

msal/request.py

@@ -0,0 +1,42 @@
+from . import oauth2
+from .exceptions import MsalServiceError
+
+
+class BaseRequest(object):
+    TOKEN_ENDPOINT_PATH = 'oauth2/v2.0/token'
+
+    def __init__(
+            self, authority=None, token_cache=None, scope=None, policy="",
+            client_id=None, client_credential=None, authenticator=None,
+            support_adfs=False, restrict_to_single_user=False):
+        if not scope:
+            raise ValueError("scope cannot be empty")
+        self.__dict__.update(locals())
+
+    def run(self):
+        # TODO Some cache stuff here
+        raw = self.get_token()
+        if 'error' in raw:
+            raise MsalServiceError(**raw)
+        # TODO: Deal with refresh_token
+        return {  # i.e. the AuthenticationResult
+            "token": raw.get('access_token'),
+            "expires_on": raw.get('expires_in'),  # TODO: Change into EPOCH
+            "tenant_id": None,  # TODO
+            "user": None,  # TODO
+            "id_token": None,  # TODO
+            "scope": set([]),  # TODO
+            }
+
+    def get_token(self):
+        raise NotImplemented("Use proper sub-class instead")
+
+
+class ClientCredentialRequest(BaseRequest):
+    def get_token(self):
+        return oauth2.ClientCredentialGrant(
+            self.client_id,
+            token_endpoint="%s%s?policy=%s" % (
+                self.authority, self.TOKEN_ENDPOINT_PATH, self.policy),
+            ).get_token(scope=self.scope, client_secret=self.client_credential)
+