feat: send notifications on post edit

this includes notification for new tags, entities and mentions.

closes #313

Author: drodil

plugins/qeta-backend/src/service/NotificationManager.ts

@@ -131,6 +131,51 @@ export class NotificationManager {
     return notificationReceivers;
   }
 
+  async onPostEdit(
+    username: string,
+    post: Post,
+    followingUsers: string[],
+  ): Promise<string[]> {
+    if (!this.notifications || !this.enabled) {
+      return [];
+    }
+
+    const notificationReceivers = [
+      ...new Set<string>([post.author, ...followingUsers]),
+    ];
+
+    if (notificationReceivers.length === 0) {
+      return [];
+    }
+
+    try {
+      const user = await this.getUserDisplayName(username);
+
+      await this.notifications.send({
+        recipients: {
+          type: 'entity',
+          entityRef: notificationReceivers,
+          excludeEntityRef: username,
+        },
+        payload: {
+          title: `Edit for ${post.type}`,
+          description: this.formatDescription(
+            `${user} edited ${post.type}: ${post.title}`,
+          ),
+          link:
+            post.type === 'question'
+              ? `/qeta/questions/${post.id}`
+              : `/qeta/articles/${post.id}`,
+          topic: `${post.type} edited`,
+          scope: `${post.type}:edit:${post.id}`,
+        },
+      });
+    } catch (e) {
+      this.logger.error(`Failed to send notification for post edit: ${e}`);
+    }
+    return notificationReceivers;
+  }
+
   async onNewAnswer(
     username: string,
     question: Post,

plugins/qeta-backend/src/service/routes/posts.ts

@@ -702,6 +702,32 @@ export const postsRoutes = (router: Router, options: RouteOptions) => {
       return;
     }
 
+    wrapAsync(async () => {
+      const newTags = tags.filter(t => !originalPost.tags?.includes(t));
+      const newEntities = entities.filter(
+        e => !originalPost.entities?.includes(e),
+      );
+
+      console.log(newTags, newEntities);
+      const followingUsers = await Promise.all([
+        database.getUsersForTags(newTags),
+        database.getUsersForEntities(newEntities),
+      ]);
+
+      const sent = await notificationMgr.onPostEdit(
+        username,
+        post,
+        followingUsers.flat(),
+      );
+      const originalMentions = findEntityMentions(originalPost.content);
+      const mentions = findEntityMentions(request.body.content);
+      const newMentions = mentions.filter(m => !originalMentions.includes(m));
+
+      if (newMentions.length > 0) {
+        await notificationMgr.onMention(username, post, newMentions, sent);
+      }
+    });
+
     events?.publish({
       topic: 'qeta',
       eventPayload: {

plugins/qeta-backend/src/service/routes/routeUtil.ts

@@ -36,7 +36,7 @@ export const getTags = async (
   return tags.slice(0, maxTags);
 };
 
-export const getEntities = (request: Request, config: Config) => {
+export const getEntities = (request: Request, config: Config): string[] => {
   const maxEntities = config.getOptionalNumber('qeta.entities.max') ?? 3;
   let entities = request.body.entities;
   if (Array.isArray(entities)) {