piyueh · February 26, 2021 23:30 · Feb 26, 2021 · Feb 26, 2021 · Feb 26, 2021
diff --git a/offlineimap_funcs.py b/offlineimap_funcs.py
@@ -18,28 +18,6 @@
 import google_auth_oauthlib
 
 
-def _convert_to_abs_path(client_credfile):
-    """Convert a credential json file path to an absolute path.
-
-    Arguments
-    ---------
-    client_credfile : str or pathlike
-        Path to a JSON file that has client credentials. It can be created & downloaded from Google Cloud Console.
-
-    Returns
-    -------
-    If the provided client_credfile is originally a relative path, we assume it is relative to the parent folder of this
-    script and return an absolute path.
-    """
-
-    client_credfile = pathlib.Path(client_credfile).expanduser()
-
-    if not client_credfile.is_absolute():
-        client_credfile = pathlib.Path(__file__).parent.joinpath(client_credfile).expanduser()
-
-    return client_credfile.resolve()
-
-
 def get_gmail_creds(account, client_credfile, scope=["https://mail.google.com/"]):
     """Get GMail account credential.
 

diff --git a/offlineimap_funcs.py b/offlineimap_funcs.py
@@ -0,0 +1,120 @@
+#! /usr/bin/env python
+# -*- coding: utf-8 -*-
+# vim:fenc=utf-8
+#
+# Copyright © 2021 Pi-Yueh Chuang <[email protected]>
+#
+# Distributed under terms of the BSD 3-Clause license.
+
+"""Functions used by an offlineimap instance.
+
+Prerequisites:
+    * google-auth: https://google-auth.readthedocs.io
+    * google-auth-oauthlib: https://google-auth-oauthlib.readthedocs.io
+"""
+import pathlib
+import pickle
+import google.auth
+import google_auth_oauthlib
+
+
+def _convert_to_abs_path(client_credfile):
+    """Convert a credential json file path to an absolute path.
+
+    Arguments
+    ---------
+    client_credfile : str or pathlike
+        Path to a JSON file that has client credentials. It can be created & downloaded from Google Cloud Console.
+
+    Returns
+    -------
+    If the provided client_credfile is originally a relative path, we assume it is relative to the parent folder of this
+    script and return an absolute path.
+    """
+
+    client_credfile = pathlib.Path(client_credfile).expanduser()
+
+    if not client_credfile.is_absolute():
+        client_credfile = pathlib.Path(__file__).parent.joinpath(client_credfile).expanduser()
+
+    return client_credfile.resolve()
+
+
+def get_gmail_creds(account, client_credfile, scope=["https://mail.google.com/"]):
+    """Get GMail account credential.
+
+    Arguments
+    ---------
+    account : str
+        Name of the account; used for naming the user credential file.
+    client_credfile : str or pathlike
+        Path to a JSON file that has client credentials. It can be created & downloaded from Google Cloud Console.
+
+    Returns
+    -------
+    A `google.oauth2.credentials.Credentials` instance.
+    """
+
+    # process and save the absolute path of the credential file
+    client_credfile = pathlib.Path(client_credfile).expanduser()
+
+    if not client_credfile.is_absolute():
+        client_credfile = pathlib.Path(__file__).parent.joinpath(client_credfile).expanduser()
+
+    client_credfile = client_credfile.resolve()
+
+    # token file contains pickled credentials of both the client and user-consented token
+    user_credfile = pathlib.Path(__file__).expanduser().resolve().parent.joinpath(account+".cred")
+
+    # try to see if the account's credential file exist; if so, read it
+    if user_credfile.exists():
+        with open(user_credfile, "rb") as fobj:
+            user_creds = pickle.load(fobj)
+
+        # return the credential object
+        if user_creds.valid:
+            return user_creds
+    else:
+        user_creds = None
+
+    # user credentials exist but expired, just renew it if refresh token exists
+    if user_creds and user_creds.expired and user_creds.refresh_token:
+        user_creds.refresh(google.auth.transport.requests.Request())
+        return user_creds
+
+    # user credentials does not exist or does not have a refresh token; open the browser for consent
+    flow = google_auth_oauthlib.flow.InstalledAppFlow.from_client_secrets_file(client_credfile, scope)
+    user_creds = flow.run_local_server(port=59843)
+
+    with open(user_credfile, "wb") as fobj:
+        pickle.dump(user_creds, fobj)
+
+    return user_creds
+
+
+def get_gmail_client_id(account, client_credfile):
+    """Get the client id (in bytes) from credentials."""
+    creds = get_gmail_creds(account, client_credfile)
+    return bytes(creds.client_id, "utf-8")  # return `bytes`
+    # return creds.client_id  # return `str`
+
+
+def get_gmail_client_secret(account, client_credfile):
+    """Get the client secret (in bytes) from credentials."""
+    creds = get_gmail_creds(account, client_credfile)
+    return bytes(creds.client_secret, "utf-8")  # return `bytes`
+    # return creds.client_secret  # return `str`
+
+
+def get_gmail_token(account, client_credfile):
+    """Get the token (in bytes) from credentials."""
+    creds = get_gmail_creds(account, client_credfile)
+    return bytes(creds.token, "utf-8")  # return `bytes`
+    # return creds.token  # return `str`
+
+
+def get_gmail_refresh_token(account, client_credfile):
+    """Get the refresh token (in bytes) from credentials."""
+    creds = get_gmail_creds(account, client_credfile)
+    return bytes(creds.refresh_token, "utf-8")  # return `bytes`
+    # return creds.refresh_token  # return `str`