Update Gdrive integration (Error Handling on Callback and wording)

cps/gdrive.py

@@ -34,18 +34,17 @@ from flask import Blueprint, flash, request, redirect, url_for, abort
 from flask_babel import gettext as _
 from flask_login import login_required
 
-try:
-    from googleapiclient.errors import HttpError
-except ImportError:
-    pass
-
 from . import logger, gdriveutils, config, ub, calibre_db
 from .web import admin_required
 
-
 gdrive = Blueprint('gdrive', __name__)
 log = logger.create()
 
+try:
+    from googleapiclient.errors import HttpError
+except ImportError as err:
+    log.debug(("Cannot import googleapiclient, using gdrive will not work: %s", err))
+
 current_milli_time = lambda: int(round(time() * 1000))
 
 gdrive_watch_callback_token = 'target=calibreweb-watch_files'
@@ -73,7 +72,7 @@ def google_drive_callback():
         credentials = gdriveutils.Gauth.Instance().auth.flow.step2_exchange(auth_code)
         with open(gdriveutils.CREDENTIALS, 'w') as f:
             f.write(credentials.to_json())
-    except ValueError as error:
+    except (ValueError, AttributeError) as error:
         log.error(error)
     return redirect(url_for('admin.configuration'))
 
@@ -94,7 +93,7 @@ def watch_gdrive():
         try:
             result = gdriveutils.watchChange(gdriveutils.Gdrive.Instance().drive, notification_id,
                                'web_hook', address, gdrive_watch_callback_token, current_milli_time() + 604800*1000)
-            config.config_google_drive_watch_changes_response = json.dumps(result)
+            # config.config_google_drive_watch_changes_response = json.dumps(result)
             # after save(), config_google_drive_watch_changes_response will be a json object, not string
             config.save()
         except HttpError as e:
@@ -118,7 +117,7 @@ def revoke_watch_gdrive():
                                     last_watch_response['resourceId'])
         except HttpError:
             pass
-        config.config_google_drive_watch_changes_response = None
+        config.config_google_drive_watch_changes_response = {}
         config.save()
     return redirect(url_for('admin.configuration'))