Message Requests

ts/RemoteConfig.ts

@@ -0,0 +1,94 @@
+// tslint:disable: no-backbone-get-set-outside-model
+import { get, throttle } from 'lodash';
+import { WebAPIType } from './textsecure/WebAPI';
+
+type ConfigKeyType = 'desktop.messageRequests';
+type ConfigValueType = {
+  name: ConfigKeyType;
+  enabled: boolean;
+  enabledAt?: number;
+};
+type ConfigMapType = { [key: string]: ConfigValueType };
+type ConfigListenerType = (value: ConfigValueType) => unknown;
+type ConfigListenersMapType = {
+  [key: string]: Array<ConfigListenerType>;
+};
+
+function getServer(): WebAPIType {
+  const OLD_USERNAME = window.storage.get<string>('number_id');
+  const USERNAME = window.storage.get<string>('uuid_id');
+  const PASSWORD = window.storage.get<string>('password');
+
+  return window.WebAPI.connect({
+    username: (USERNAME || OLD_USERNAME) as string,
+    password: PASSWORD as string,
+  });
+}
+
+let config: ConfigMapType = {};
+const listeners: ConfigListenersMapType = {};
+
+export async function initRemoteConfig() {
+  config = window.storage.get('remoteConfig') || {};
+  await maybeRefreshRemoteConfig();
+}
+
+export function onChange(key: ConfigKeyType, fn: ConfigListenerType) {
+  const keyListeners: Array<ConfigListenerType> = get(listeners, key, []);
+  keyListeners.push(fn);
+  listeners[key] = keyListeners;
+
+  return () => {
+    listeners[key] = listeners[key].filter(l => l !== fn);
+  };
+}
+
+const refreshRemoteConfig = async () => {
+  const now = Date.now();
+  const server = getServer();
+  const newConfig = await server.getConfig();
+
+  // Process new configuration in light of the old configuration
+  // The old configuration is not set as the initial value in reduce because
+  // flags may have been deleted
+  const oldConfig = config;
+  config = newConfig.reduce((previous, { name, enabled }) => {
+    const previouslyEnabled: boolean = get(oldConfig, [name, 'enabled'], false);
+    // If a flag was previously not enabled and is now enabled, record the time it was enabled
+    const enabledAt: number | undefined =
+      previouslyEnabled && enabled ? now : get(oldConfig, [name, 'enabledAt']);
+
+    const value = {
+      name: name as ConfigKeyType,
+      enabled,
+      enabledAt,
+    };
+
+    // If enablement changes at all, notify listeners
+    const currentListeners = listeners[name] || [];
+    if (previouslyEnabled !== enabled) {
+      currentListeners.forEach(listener => {
+        listener(value);
+      });
+    }
+
+    // Return new configuration object
+    return {
+      ...previous,
+      [name]: value,
+    };
+  }, {});
+
+  window.storage.put('remoteConfig', config);
+};
+
+export const maybeRefreshRemoteConfig = throttle(
+  refreshRemoteConfig,
+  // Only fetch remote configuration if the last fetch was more than two hours ago
+  2 * 60 * 60 * 1000,
+  { trailing: false }
+);
+
+export function isEnabled(name: ConfigKeyType): boolean {
+  return get(config, [name, 'enabled'], false);
+}