AppUpdateWarning class and injectable

Signed-off-by: Alex Andreev <alex.andreev.email@gmail.com>

src/renderer/app-freshness/app-update-warning.injectable.ts

@@ -0,0 +1,22 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+import { getInjectable } from "@ogre-tools/injectable";
+import { AppUpdateWarning } from "./app-update-warning";
+
+const appUpdateWarningInjectable = getInjectable({
+  id: "app-update-warning",
+
+  instantiate: () => {
+    AppUpdateWarning.resetInstance();
+
+    return AppUpdateWarning.createInstance({
+      releaseDate: "Wed, 04 May 2022 02:35:00 +0300",
+    });
+  },
+
+  causesSideEffects: true,
+});
+
+export default appUpdateWarningInjectable;

src/renderer/app-freshness/app-update-warning.ts

@@ -0,0 +1,49 @@
+/**
+ * Copyright (c) OpenLens Authors. All rights reserved.
+ * Licensed under MIT License. See LICENSE in root directory for more information.
+ */
+import { computed, makeObservable, observable } from "mobx";
+import type { UpdateAvailableFromMain } from "../../common/ipc";
+import { ipcRendererOn, UpdateAvailableChannel } from "../../common/ipc";
+import { Singleton } from "../utils";
+import moment from "moment";
+
+interface Dependencies {
+  releaseDate: string;
+}
+
+export class AppUpdateWarning extends Singleton {
+  @observable updateReleaseDate = "";
+
+  constructor(private dependencies: Dependencies) {
+    super();
+    makeObservable(this);
+
+    ipcRendererOn(UpdateAvailableChannel, (event, ...[, updateInfo]: UpdateAvailableFromMain) => {
+      this.updateReleaseDate = updateInfo.releaseDate;
+    });
+  }
+
+  @computed
+  get warningLevel(): "high" | "medium" | "light" | "" {
+    const update = moment(this.updateReleaseDate);
+    const release = moment(this.dependencies.releaseDate);
+
+    const duration = moment.duration(update.diff(release));
+    const days = duration.asDays();
+
+    if (days >= 27) {
+      return "high";
+    }
+
+    if (days >= 25 && days < 27) {
+      return "medium";
+    }
+
+    if (days >= 20 && days < 25) {
+      return "light";
+    }
+
+    return "";
+  }
+}