[IMP] google_calendar: add single event synchronization

Purpose
=======
Add the possibility to only synchronize one specific event of
a user calendar instead of syncing the whole calendar.

Specification
=============
In certain cases, we do not want to synchronize the whole user
calendar with all the events and recurrences but only a specific
event. For example, in appointment, to retrieve the generated
google meet url of a specified event.

To perform the single event synchronization a synchronization
token is needed, meaning we cannot do a single event
synchronization prior to a full calendar synchronization as it
is the full sync which generates the temporary sync token.

To prevent the need of doing a full sync before a single event sync,
the permanent synchronization token is been used instead of
the temporary one when performing a single event synchronization.

Task-3285601

Part-of: odoo/odoo#133921

addons/google_calendar/models/res_users.py

@@ -53,24 +53,10 @@ class User(models.Model):
 
     def _sync_google_calendar(self, calendar_service: GoogleCalendarService):
         self.ensure_one()
-        if self._get_google_sync_status() != "sync_active":
+        results = self._sync_request(calendar_service)
+        if not results or not results.get('events'):
             return False
-        # don't attempt to sync when another sync is already in progress, as we wouldn't be
-        # able to commit the transaction anyway (row is locked)
-        self.env.cr.execute("""SELECT id FROM res_users WHERE id = %s FOR NO KEY UPDATE SKIP LOCKED""", [self.id])
-        if not self.env.cr.rowcount:
-            _logger.info("skipping calendar sync, locked user %s", self.login)
-            return False
-
-        full_sync = not bool(self.google_calendar_sync_token)
-        with google_calendar_token(self) as token:
-            try:
-                events, next_sync_token, default_reminders = calendar_service.get_events(self.google_calendar_account_id.calendar_sync_token, token=token)
-            except InvalidSyncToken:
-                events, next_sync_token, default_reminders = calendar_service.get_events(token=token)
-                full_sync = True
-        self.google_calendar_account_id.calendar_sync_token = next_sync_token
-
+        events, default_reminders, full_sync = results.values()
         # Google -> Odoo
         send_updates = not full_sync
         events.clear_type_ambiguity(self.env)
@@ -89,6 +75,50 @@ class User(models.Model):
 
         return bool(events | synced_events) or bool(recurrences | synced_recurrences)
 
+    def _sync_single_event(self, calendar_service: GoogleCalendarService, odoo_event, event_id):
+        self.ensure_one()
+        results = self._sync_request(calendar_service, event_id)
+        if not results or not results.get('events'):
+            return False
+        event, default_reminders, full_sync = results.values()
+        # Google -> Odoo
+        send_updates = not full_sync
+        event.clear_type_ambiguity(self.env)
+        synced_events = self.env['calendar.event']._sync_google2odoo(event, default_reminders=default_reminders)
+        # Odoo -> Google
+        odoo_event.with_context(send_updates=send_updates)._sync_odoo2google(calendar_service)
+        return bool(odoo_event | synced_events)
+
+    def _sync_request(self, calendar_service, event_id=None):
+        if self._get_google_sync_status() != "sync_active":
+            return False
+        # don't attempt to sync when another sync is already in progress, as we wouldn't be
+        # able to commit the transaction anyway (row is locked)
+        self.env.cr.execute("""SELECT id FROM res_users WHERE id = %s FOR NO KEY UPDATE SKIP LOCKED""", [self.id])
+        if not self.env.cr.rowcount:
+            _logger.info("skipping calendar sync, locked user %s", self.login)
+            return False
+
+        full_sync = not bool(self.google_calendar_sync_token)
+        with google_calendar_token(self) as token:
+            try:
+                if not event_id:
+                    events, next_sync_token, default_reminders = calendar_service.get_events(self.google_calendar_account_id.calendar_sync_token, token=token)
+                else:
+                    # We force the sync_token parameter to avoid doing a full sync.
+                    # Other events are fetched when the calendar view is displayed.
+                    events, next_sync_token, default_reminders = calendar_service.get_events(sync_token=token, token=token, event_id=event_id)
+            except InvalidSyncToken:
+                events, next_sync_token, default_reminders = calendar_service.get_events(token=token)
+                full_sync = True
+        if next_sync_token:
+            self.google_calendar_account_id.calendar_sync_token = next_sync_token
+        return {
+            'events': events,
+            'default_reminders': default_reminders,
+            'full_sync': full_sync,
+        }
+
     @api.model
     def _sync_all_google_calendar(self):
         """ Cron job """

addons/google_calendar/utils/google_calendar.py

@@ -29,8 +29,10 @@ class GoogleCalendarService():
         self.google_service = google_service
 
     @requires_auth_token
-    def get_events(self, sync_token=None, token=None, timeout=TIMEOUT):
+    def get_events(self, sync_token=None, token=None, event_id=None, timeout=TIMEOUT):
         url = "/calendar/v3/calendars/primary/events"
+        if event_id:
+            url += f"/{event_id}"
         headers = {'Content-type': 'application/json'}
         params = {'access_token': token}
         if sync_token:
@@ -51,6 +53,11 @@ class GoogleCalendarService():
                 raise InvalidSyncToken("Invalid sync token. Full sync required")
             raise e
 
+        if event_id:
+            next_sync_token = None
+            default_reminders = ()
+            return GoogleEvent([data]), next_sync_token, default_reminders
+
         events = data.get('items', [])
         next_page_token = data.get('nextPageToken')
         while next_page_token: