XO Integration Part II

packages/stack/src/storage/activities.ts

@@ -25,10 +25,18 @@ export interface Activity {
 // Define the snapshot structure
 export type SnapshotByType = {
   [type: string]: {
-    [id: string]: Activity;
+    [entityId: string]: Activity;
   };
 };
 
+export type ActivitiesIndexedByKey<T extends Activity = Activity> = {
+  [entityId: string]: T;
+};
+
+export type ActivitiesIndexedByEntityId<T extends Activity = Activity> = {
+  [key: string]: T;
+};
+
 // Policy type definition
 export type PolicyFunction = (
   existingActivity: Activity | undefined,
@@ -36,6 +44,7 @@ export type PolicyFunction = (
 ) => Activity;
 
 export type ActivitiesEvents = {
+  snapshotUpdated: undefined;
   [key: `updated:${string}`]: { activity: Activity };
 };
 
@@ -172,12 +181,17 @@ export class Activities extends EventEmitter<ActivitiesEvents> {
   /**
    * Get all activities of a specific type
    */
-  public getByType<T extends Activity>(type: T['key']): T[] {
-    const activities = this.snapshot[type];
+  public getByKey<T extends Activity>(
+    key: T['key'],
+  ): ActivitiesIndexedByKey<T> {
+    const activities = this.snapshot[key];
     if (!activities) {
-      return [];
+      return {};
     }
-    return Object.values(activities) as T[];
+
+    // NOTE: We want to return a new object, not a reference to our current object.
+    //       But we only need to "clone" the first level as each activity itself is immutable.
+    return { ...activities } as ActivitiesIndexedByKey<T>;
   }
 
   /**
@@ -227,6 +241,9 @@ export class Activities extends EventEmitter<ActivitiesEvents> {
 
       // Emit the updated activity.
       this.emit(`updated:${activity.key}`, { activity });
+
+      // Emit an event indicating our snapshot has been updated.
+      this.emit('snapshotUpdated', undefined);
     } else if (storeKey !== this.storeKeyMap.get(snapshotKey)) {
       // If we kept the existing activity, delete the new activity from the store
       // await this.store.set(storeKey, null);
@@ -261,6 +278,8 @@ export class Activities extends EventEmitter<ActivitiesEvents> {
       await this.processActivity(storeKey, activity);
     }
 
+    this.emit('snapshotUpdated', undefined);
+
     return this.snapshot;
   }