DemoBot :Debounce hello messages.

bots/lib/bot/handlers/demo.ts

@@ -1,7 +1,10 @@
 import type { XMPPUser } from '../types'
+import { logger } from '../../logger'
 import { BotHandler } from './base'
 
 export class BotHandlerDemo extends BotHandler {
+  protected readonly lastHellos: Map<string, Date> = new Map()
+
   protected init (): void {
     const room = this.room
     room.on('room_join', (user: XMPPUser) => {
@@ -11,9 +14,23 @@ export class BotHandlerDemo extends BotHandler {
       if (!room.isOnline()) {
         return
       }
-      room.sendGroupchat(
+      const lastHello = this.lastHellos.get(user.nick)
-        `Hello ${user.nick}! I'm the DemoBot, I'm here to demonstrate the chatroom.`
+      const now = new Date()
-      ).catch(() => {})
+      let msg: string
+      if (lastHello) {
+        logger.debug(`The user ${user.nick} was already seen at ${lastHello.toString()}`)
+        if ((now.getTime() - lastHello.getTime()) < 3600 * 1000) { // no more than one hello per hour
+          logger.info(`The user ${user.nick} was seen to recently, no message to send.`)
+          return
+        }
+        logger.info(`The user ${user.nick} was seen a long time ago, sending a message.`)
+        msg = `Hello ${user.nick}! Happy to see you again.`
+      } else {
+        logger.info(`The user ${user.nick} is here for the first time. Sending a message.`)
+        msg = `Hello ${user.nick}! I'm the DemoBot, I'm here to demonstrate the chatroom.`
+      }
+      this.lastHellos.set(user.nick, now)
+      room.sendGroupchat(msg).catch(() => {})
     })
   }
 }