deployment-talks/chat-app/src/chat-room.ts

import { EventEmitter } from "events";

export type Chatter = {
  name: string,
};

export const chatters = new Array<Chatter>();

export type Message = {
  message: string,
  timestamp: Date,
  chatter: string,
};

export function createMessageString(message: Message): string {
  return `${message.chatter.name}: ${message.message}`;
}

export class ChatRoom extends EventEmitter {
  protected messages: Message[];

  public constructor() {
    super();
    this.messages = new Array<Message>();
  }

  public getMessages(): Message[] {
    return this.messages;
  }

  public addMessage(message: Message) {
    this.messages.push(message);
    this.emit("message-added", { message });
  }

  public getMessagesAsArray(): string[] {
    return this.messages.map(m => createMessageString(m));
  }

  public getNewestMessage(): Message {
    const message = this.messages[this.messages - 1];
  }

  // set up the lifetime to clear messages in memory
  protected pruneMessages(lifetime: number): void {

  }
}

export const chatRoom = new ChatRoom();