From cd811195f1ea11290e2c30798f19d0847447877f Mon Sep 17 00:00:00 2001
From: Sergey Yarkov <serzh.yarkov@gmail.com>
Date: Wed, 23 Feb 2022 20:02:37 +0300
Subject: [PATCH] feat: added history limit to messages store

---
 CHANGELOG.md                   |  1 +
 app/Services/WsService.ts      |  7 ++++---
 app/Store/MessageStore.ts      |  8 ++++++++
 app/Store/NotificationStore.ts | 26 ++++++++++++++------------
 4 files changed, 27 insertions(+), 15 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 77c40e9..92aaab0 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -8,6 +8,7 @@
 
 ## Added
 
+- Saving latest notifications about new messages
 - Chat between users. (chat history).
 - About description for user and `last_login` column date
 - Updating info api route of authorized user
diff --git a/app/Services/WsService.ts b/app/Services/WsService.ts
index fb08d15..65fb100 100644
--- a/app/Services/WsService.ts
+++ b/app/Services/WsService.ts
@@ -31,7 +31,7 @@ export interface ServerToClientEvents {
   /**
    * Chat
    */
-  'chat:message': (data: { content: string; time: string; from: string; to: string }) => void;
+  'chat:message': (data: { content: string; time: string; from: string; to: string; notificationId: string }) => void;
 }
 
 export interface ClientToServerEvents {
@@ -129,8 +129,9 @@ class WsService {
           };
 
           await this.messageStore.add(userId, to, message);
-          await this.notificationStore.add(to, `You received a new message.`);
-          this.io.to(to).emit('chat:message', message);
+
+          const notification = await this.notificationStore.add(to, `You received a new private message`, 'MESSAGE');
+          this.io.to(to).emit('chat:message', { ...message, notificationId: notification.id });
         }
       });
 
diff --git a/app/Store/MessageStore.ts b/app/Store/MessageStore.ts
index f289bdb..1403b0b 100644
--- a/app/Store/MessageStore.ts
+++ b/app/Store/MessageStore.ts
@@ -11,6 +11,7 @@ type MessageDataType = {
 };
 
 const MESSAGE_TTL = 185 * 24 * 60 * 60; // 185 days
+const MAX_MESSAGES_HISTORY = 100;
 
 class RedisMessageStore {
   public redisClient: RedisConnectionContract;
@@ -37,8 +38,15 @@ class RedisMessageStore {
         .exec();
 
       const convKey = this.createConversationKey(firstUserId, secondUserId);
+      const msgKeys = await this.redisClient.lrange(convKey, 0, -1);
+
       await this.redisClient.lpush(convKey, msgKey);
 
+      if (msgKeys.length >= MAX_MESSAGES_HISTORY) {
+        const deletedMsgKey = await this.redisClient.rpop(convKey);
+        await this.redisClient.del(`message:${deletedMsgKey}`);
+      }
+
       return 'OK';
     } catch (error) {
       Logger.error(error);
diff --git a/app/Store/NotificationStore.ts b/app/Store/NotificationStore.ts
index 9009ac5..bd42094 100644
--- a/app/Store/NotificationStore.ts
+++ b/app/Store/NotificationStore.ts
@@ -5,6 +5,8 @@ import { nanoid } from 'nanoid';
 const NOTIFICATION_TTL = 185 * 24 * 60 * 60; // 185 days
 
 type NotificationType = {
+  id: string;
+  type: 'SYSTEM' | 'MESSAGE';
   content: string;
   time: string;
 };
@@ -16,25 +18,25 @@ class RedisNotificationStore {
     this.redisClient = redisClient;
   }
 
-  public async add(userId: string, message: string): Promise<'OK' | 'ERROR'> {
+  public async add(userId: string, content: string, type: NotificationType['type']): Promise<NotificationType> {
     try {
-      const key = `notification:${nanoid()}`;
+      const id = nanoid();
+      const key = `notification:${id}`;
       const timestamp = Date.now();
+      const notification = {
+        id,
+        content,
+        time: new Date(timestamp).toISOString(),
+        type,
+      };
 
       await this.redisClient.zadd(`user:${userId}`, timestamp, key);
-      await this.redisClient
-        .multi()
-        .hmset(key, {
-          content: message,
-          time: new Date(timestamp).toISOString(),
-        })
-        .expire(key, NOTIFICATION_TTL)
-        .exec();
+      await this.redisClient.multi().hmset(key, notification).expire(key, NOTIFICATION_TTL).exec();
 
-      return 'OK';
+      return notification;
     } catch (error) {
       Logger.error(error);
-      return 'ERROR';
+      return Promise.reject(error);
     }
   }