Stories: Start expiration on receipt

ts/models/messages.ts

@@ -2646,6 +2646,12 @@ export class MessageModel extends window.Backbone.Model<MessageAttributesType> {
             !isExpirationTimerUpdate(dataMessage)
           ) {
             message.set({ expireTimer: dataMessage.expireTimer });
+            if (isStory(message.attributes)) {
+              log.info(`${idLog}: Starting story expiration`);
+              message.set({
+                expirationStartTimestamp: dataMessage.timestamp,
+              });
+            }
           }
 
           if (!hasGroupV2Prop && !isStory(message.attributes)) {

ts/state/ducks/stories.ts

@@ -1222,6 +1222,10 @@ export function reducer(
         isDownloaded(newStory.attachment);
       const hasAttachmentFailed =
         hasFailed(newStory.attachment) && !hasFailed(prevStory.attachment);
+      const hasExpirationChanged =
+        (newStory.expirationStartTimestamp &&
+          !prevStory.expirationStartTimestamp) ||
+        (newStory.expireTimer && !prevStory.expireTimer);
       const readStatusChanged = prevStory.readStatus !== newStory.readStatus;
       const reactionsChanged =
         prevStory.reactions?.length !== newStory.reactions?.length;
@@ -1237,6 +1241,7 @@ export function reducer(
         hasAttachmentDownloaded ||
         hasAttachmentFailed ||
         hasBeenDeleted ||
+        hasExpirationChanged ||
         hasSendStateChanged ||
         readStatusChanged ||
         reactionsChanged;