Make addon-enabled as a clean architecture

src/content/usecases/AddonEnabledUseCase.ts

@@ -0,0 +1,40 @@
+import AddonIndicatorClient, { AddonIndicatorClientImpl }
+  from '../client/AddonIndicatorClient';
+import AddonEnabledRepository, { AddonEnabledRepositoryImpl }
+  from '../repositories/AddonEnabledRepository';
+
+export default class AddonEnabledUseCase {
+  private indicator: AddonIndicatorClient;
+
+  private repository: AddonEnabledRepository;
+
+  constructor({
+    indicator = new AddonIndicatorClientImpl(),
+    repository = new AddonEnabledRepositoryImpl(),
+  } = {}) {
+    this.indicator = indicator;
+    this.repository = repository;
+  }
+
+  async enable(): Promise<void> {
+    await this.setEnabled(true);
+  }
+
+  async disable(): Promise<void> {
+    await this.setEnabled(false);
+  }
+
+  async toggle(): Promise<void> {
+    let current = this.repository.get();
+    await this.setEnabled(!current);
+  }
+
+  getEnabled(): boolean {
+    return this.repository.get();
+  }
+
+  private async setEnabled(on: boolean): Promise<void> {
+    this.repository.set(on);
+    await this.indicator.setEnabled(on);
+  }
+}