Change google adapter to use service account.

adapters/google.py

@@ -3,47 +3,36 @@
 
 import tempfile
 import datetime
+import logging
 import os.path
 
 import json
 from google.auth.transport.requests import Request
-from google.oauth2.credentials import Credentials
+#from google.oauth2.credentials import Credentials
+from google.oauth2.service_account import Credentials
 from google_auth_oauthlib.flow import InstalledAppFlow
 from googleapiclient.discovery import build
 from googleapiclient.errors import HttpError
 
+logger = logging.getLogger(f"wp_cal.{__name__}")
+
 # If modifying these scopes, delete the file token.json.
-SCOPES = ['https://www.googleapis.com/auth/calendar']
+SCOPES = ['https://www.googleapis.com/auth/calendar.readonly']
 
 
 class Google():
 
     def __init__(self, calendar_id, *, credentials, token_file):
-        _, credentials_file = tempfile.mkstemp()
-        with open(credentials_file, 'w') as fp:
-            json.dump(credentials, fp)
-
         self.calendar_id = calendar_id
-        self.credentials_file = credentials_file
-        self.token_file = token_file
+        self.credentials_info = credentials
         self.credentials = None
 
     def login(self):
-        if os.path.exists(self.token_file):
-            self.credentials = Credentials.from_authorized_user_file(self.token_file, SCOPES)
-        if self.credentials is None or not self.credentials.valid:
-            if self.credentials is not None \
-                    and self.credentials.expired \
-                    and  self.credentials.refresh_token:
-                self.credentials.refresh(Request())
-            else:
-                flow = InstalledAppFlow.from_client_secrets_file(
-                    self.credentials_file,
-                    SCOPES,
-                )
-                self.credentials = flow.run_local_server(port=0)
-            with open(self.token_file, 'w') as token:
-                token.write(self.credentials.to_json())
+        self.credentials = Credentials.from_service_account_info(self.credentials_info, scopes=SCOPES)
+        if not self.credentials.valid:
+            self.credentials.refresh(Request())
+        logger.debug('credentials.valid = %s', repr(self.credentials.valid))
+
 
     def get_events(self, start: datetime.datetime | None=None, until: datetime.timedelta | None=None, limit=None):
         until = until if until else datetime.timedelta(days=365)
@@ -59,7 +48,7 @@ class Google():
                 maxResults=limit,
             ).execute()
         except HttpError:
-            print('an error occured')
+            logger.exception("a http error occured")
             raise
         events = events.get('items', [])
         return events