Notifications refactor (#5151

* Ongoing

* refactor

* test

* Add cleanup task

* refactor

server/queues/tasks/CleanupOldNotificationsTask.ts

@@ -0,0 +1,52 @@
+import { subMonths } from "date-fns";
+import { Op } from "sequelize";
+import Logger from "@server/logging/Logger";
+import { Notification } from "@server/models";
+import BaseTask, { TaskPriority, TaskSchedule } from "./BaseTask";
+
+type Props = Record<string, never>;
+
+export default class CleanupOldNotificationsTask extends BaseTask<Props> {
+  static cron = TaskSchedule.Daily;
+
+  public async perform() {
+    Logger.info("task", `Permanently destroying old notifications…`);
+    let count;
+
+    count = await Notification.destroy({
+      where: {
+        createdAt: {
+          [Op.lt]: subMonths(new Date(), 12),
+        },
+      },
+    });
+
+    Logger.info(
+      "task",
+      `Destroyed ${count} notifications older than 12 months…`
+    );
+
+    count = await Notification.destroy({
+      where: {
+        viewedAt: {
+          [Op.ne]: null,
+        },
+        createdAt: {
+          [Op.lt]: subMonths(new Date(), 6),
+        },
+      },
+    });
+
+    Logger.info(
+      "task",
+      `Destroyed ${count} viewed notifications older than 6 months…`
+    );
+  }
+
+  public get options() {
+    return {
+      attempts: 1,
+      priority: TaskPriority.Background,
+    };
+  }
+}