Add session parameter (#79)

* Add session parameter to OneDriveFS

* Update README

README.md

@@ -6,6 +6,8 @@ Implementation of pyfilesystem2 file system using OneDrive
 
 # Usage
 
+`fs.onedrivefs` can create a [`requests_oauthlib.OAuth2Session`](https://requests-oauthlib.readthedocs.io/en/latest/oauth2_workflow.html#) for you. This way the `OAuth2Session` is going to refresh the tokens for you.
+
 ``` python
 onedriveFS = OneDriveFS(
   clientId=<your client id>,
@@ -16,4 +18,37 @@ onedriveFS = OneDriveFS(
 # onedriveFS is now a standard pyfilesystem2 file system
 ```
 
+You can handle the tokens outside of the library by passing a [`requests.Session`](https://requests.readthedocs.io/en/latest/user/advanced/#session-objects).
+Here is an example of a custom session using [MSAL Python](https://learn.microsoft.com/en-us/entra/msal/python/)
+
+``` python
+class MSALSession(OAuth2Session):
+  def __init__(self, client: msal.ClientApplication):
+    super().__init__()
+    self.client = client
+
+  def request(self, *args, **kwargs):
+    account = self.client.get_accounts()[0]
+    self.token = self.client.acquire_token_silent_with_error(
+      scopes=["Files.ReadWrite"], account=account
+    )
+
+    return super().request(*args, **kwargs)
+
+client = msal.ConfidentialClientApplication(
+  client_id=<your client id>,
+  client_credential=<your client secret>,
+  authority=f"https://login.microsoftonline.com/<your tenant>",
+  token_cache=<your token cache>,
+)
+
+# Authentication flow to populate the token cache
+# YOUR AUTHENTICATION FLOW
+
+session = MSALSession(client=client)
+onedriveFS = OneDriveFS(session=session)
+
+# onedriveFS is now a standard pyfilesystem2 file system
+```
+
 Register your app [here](https://docs.microsoft.com/en-us/graph/auth-register-app-v2) to get a client ID and secret

fs/onedrivefs/onedrivefs.py

@@ -11,7 +11,7 @@
 from fs.path import basename, dirname
 from fs.subfs import SubFS
 from fs.time import datetime_to_epoch, epoch_to_datetime
-from requests import codes, get
+from requests import codes, get, Session
 from requests_oauthlib import OAuth2Session
 
 _log = getLogger(__name__)
@@ -155,10 +155,25 @@ def delete_subscription(self, id_):
 	def update_subscription(self, id_, expiration_date_time):
 		return self.delegate_fs().update_subscription(id_, expiration_date_time)
 
-class OneDriveSession(OAuth2Session):
-	def __init__(self, *args, drive_root, **kwargs):
+class OneDriveSession:
+	def __init__(self, drive_root, session: Session):
 		self._drive_root = drive_root
-		super().__init__(*args, **kwargs)
+		self.session = session
+
+	def get(self, *args, **kwargs):
+		return self.session.get(*args, **kwargs)
+
+	def post(self, *args, **kwargs):
+		return self.session.post(*args, **kwargs)
+
+	def patch(self, *args, **kwargs):
+		return self.session.patch(*args, **kwargs)
+
+	def put(self, *args, **kwargs):
+		return self.session.put(*args, **kwargs)
+
+	def delete(self, *args, **kwargs):
+		return self.session.delete(*args, **kwargs)
 
 	def path_url(self, path, extra):
 		# the path must start with '/'
@@ -199,20 +214,28 @@ class OneDriveFS(FS):
 	subfs_class = SubOneDriveFS
 	_service_root = 'https://graph.microsoft.com/v1.0'
 
-	def __init__(self, clientId, clientSecret, token, SaveToken, tenant='consumers', **kwargs):
+	def __init__(self, clientId=None, clientSecret=None, token=None, SaveToken=None, tenant='consumers', session=None, **kwargs):
 		super().__init__()
 
 		self.set_drive(**kwargs)
-		auto_refresh_kwargs = {'client_id': clientId}
-		if clientSecret is not None:
-			auto_refresh_kwargs['client_secret'] = clientSecret
+
+		if session is None:
+
+			auto_refresh_kwargs = {'client_id': clientId}
+			if clientSecret is not None:
+				auto_refresh_kwargs['client_secret'] = clientSecret
+
+			session = OAuth2Session(
+				client_id=clientId,
+				token=token,
+				auto_refresh_kwargs=auto_refresh_kwargs,
+				auto_refresh_url=f'https://login.microsoftonline.com/{tenant}/oauth2/v2.0/token',
+				token_updater=SaveToken,
+			)
+
 		self.session = OneDriveSession(
-			client_id=clientId,
-			token=token,
-			auto_refresh_kwargs=auto_refresh_kwargs,
-			auto_refresh_url=f'https://login.microsoftonline.com/{tenant}/oauth2/v2.0/token',
-			token_updater=SaveToken,
-			drive_root=self._drive_root
+			drive_root=self._drive_root,
+			session=session
 		)
 
 		self._meta = {