copy common ts code over from browser repo

src/services/settings.service.ts

@@ -0,0 +1,61 @@
+import UserService from './user.service';
+import UtilsService from './utils.service';
+
+const Keys = {
+    settingsPrefix: 'settings_',
+    equivalentDomains: 'equivalentDomains',
+};
+
+export default class SettingsService {
+    private settingsCache: any;
+
+    constructor(private userService: UserService) {
+    }
+
+    clearCache(): void {
+        this.settingsCache = null;
+    }
+
+    getEquivalentDomains(): Promise<any> {
+        return this.getSettingsKey(Keys.equivalentDomains);
+    }
+
+    async setEquivalentDomains(equivalentDomains: string[][]) {
+        await this.setSettingsKey(Keys.equivalentDomains, equivalentDomains);
+    }
+
+    async clear(userId: string): Promise<void> {
+        await UtilsService.removeFromStorage(Keys.settingsPrefix + userId);
+        this.settingsCache = null;
+    }
+
+    // Helpers
+
+    private async getSettings(): Promise<any> {
+        if (this.settingsCache == null) {
+            const userId = await this.userService.getUserId();
+            this.settingsCache = UtilsService.getObjFromStorage(Keys.settingsPrefix + userId);
+        }
+        return this.settingsCache;
+    }
+
+    private async getSettingsKey(key: string): Promise<any> {
+        const settings = await this.getSettings();
+        if (settings != null && settings[key]) {
+            return settings[key];
+        }
+        return null;
+    }
+
+    private async setSettingsKey(key: string, value: any): Promise<void> {
+        const userId = await this.userService.getUserId();
+        let settings = await this.getSettings();
+        if (!settings) {
+            settings = {};
+        }
+
+        settings[key] = value;
+        await UtilsService.saveObjToStorage(Keys.settingsPrefix + userId, settings);
+        this.settingsCache = settings;
+    }
+}