text: const users = []
  
  const addUser = ({id, username, room}) => {
    if(!username || !room){
      return{
          error: 'username and room are required'
      }
    }  
    
    username = username.trim().toLowerCase()
      room = room.trim().toLowerCase()
  
      const existingUser = users.find((user)=>user.room === room && user.username === username)
      if(existingUser){
          return {
              error: "username is alredy in use in this sesion"
          }
      }
      const user = {id, username, room}
      users.push(user)
      return {user}
  }
  
  const removeUser = (id) => {
     const index = users.findIndex((user)=> user.id === id) 
     if(index !== -1){
         return users.splice(index, 1)[0]
     }
  }
  const getUser = (id) => users.find((user)=> user.id === id)
  
  const getUserInRoom = (room) => {
      room = room.trim().toLowerCase()
      return users.filter((user) => user.room === room)
  }
  
  module.exports = {
      getUser,
      getUserInRoom,
      removeUser,
      addUser
  }