feat: archive bindings on Feishu lifecycle events

hub/src/feishu/client.ts

@@ -106,6 +106,13 @@ export interface CardActionEvent {
   readonly token?: string;
 }
 
+/** A binding-ending Feishu event delivered to this application's bot. */
+export interface FeishuBindingLifecycleEvent {
+  readonly eventId: string;
+  readonly chatId: string;
+  readonly reason: "chat_dissolved" | "bot_removed";
+}
+
 interface ContactBasicUser {
   readonly name?: string | undefined;
   readonly i18n_name?: {
@@ -922,6 +929,7 @@ export async function startFeishuListenerWithClient(
   onMessage: (event: MessageReceiveEvent, rt: FeishuRuntime) => Promise<void>,
   onCardAction?: (event: CardActionEvent, rt: FeishuRuntime) => Promise<void>,
   onTerminalError?: (error: Error) => void,
+  onBindingLifecycle?: (event: FeishuBindingLifecycleEvent) => Promise<void>,
 ): Promise<FeishuRuntime> {
   let state: "STARTING" | "READY" | "FAILED" = "STARTING";
   let resolveReady!: () => void;
@@ -963,6 +971,14 @@ export async function startFeishuListenerWithClient(
         .catch((e) => { logger.error({ err: e }, "feishu card action handler threw"); });
     };
   }
+  if (onBindingLifecycle !== undefined) {
+    handlers["im.chat.disbanded_v1"] = async (data) => {
+      await dispatchBindingLifecycleEvent(data, "chat_dissolved", onBindingLifecycle, logger);
+    };
+    handlers["im.chat.member.bot.deleted_v1"] = async (data) => {
+      await dispatchBindingLifecycleEvent(data, "bot_removed", onBindingLifecycle, logger);
+    };
+  }
   await wsClient.start({ eventDispatcher: new lark.EventDispatcher({}).register(handlers) });
   let timeout: ReturnType<typeof setTimeout> | undefined;
   const startupTimeout = new Promise<never>((_resolve, reject) => {
@@ -977,6 +993,36 @@ export async function startFeishuListenerWithClient(
   return rt;
 }
 
+async function dispatchBindingLifecycleEvent(
+  data: unknown,
+  reason: FeishuBindingLifecycleEvent["reason"],
+  onBindingLifecycle: (event: FeishuBindingLifecycleEvent) => Promise<void>,
+  logger: FastifyBaseLogger,
+): Promise<void> {
+  const event = bindingLifecycleEventFrom(data, reason);
+  if (event === null) {
+    logger.warn({ reason }, "feishu binding lifecycle event missing chat id");
+    return;
+  }
+  await onBindingLifecycle(event);
+}
+
+function bindingLifecycleEventFrom(
+  data: unknown,
+  reason: FeishuBindingLifecycleEvent["reason"],
+): FeishuBindingLifecycleEvent | null {
+  if (typeof data !== "object" || data === null) return null;
+  const event = data as { readonly chat_id?: unknown; readonly event_id?: unknown; readonly header?: { readonly event_id?: unknown } };
+  if (typeof event.chat_id !== "string" || event.chat_id.trim() === "") return null;
+  const eventId = typeof event.event_id === "string" && event.event_id !== ""
+    ? event.event_id
+    : typeof event.header?.event_id === "string" && event.header.event_id !== ""
+      ? event.header.event_id
+      : undefined;
+  if (eventId === undefined) return null;
+  return { chatId: event.chat_id, reason, eventId };
+}
+
 export async function startFeishuListener(
   config: FeishuConfig,
   logger: FastifyBaseLogger,