chat.js

//adding new chat documents
//setting up a real-time listener to get new chats
//update te username
//updating the room


class Chatroom{
    constructor(room,username){
        this.room=room;
        this.username=username;
        this.chats = db.collection('chats');
        this.unsubscribe;

    }
    
    async addChat(message){
        //format char object
        const now = new Date();
        const chat = {
            message:message,
            username:this.username,
            room:this.room,
            created_at: firebase.firestore.Timestamp.fromDate(now)
        };
       //save the chat document
       const response = await this.chats.add(chat);
       return response;
    }

     getChats(callback){
        this.unsubscribe = this.chats
        .where('room','==',this.room)
        .orderBy('created_at')
        .onSnapshot(snapshot=>{
            snapshot.docChanges().forEach(change=>{
             if(change.type==='added'){
                 //update ui
                 callback(change.doc.data());
             }
            });
        });
    }

    updateName(username){
        this.username=username;
        localStorage.setItem('username',username)
    }
    updateRoom(room){
      this.room = room;
      console.log('room updated')
      if(this.unsubscribe){
        this.unsubscribe()
      }
    }

}