ScalaWorkshopExample.scala

object ScalaWorkshopExample extends App {
  class User(val name: String) {
    def greet(): Unit = println(s"Hi, my name is $name")
  }

  class Message(val sender: User, val content: String)

  abstract class Chat(val members: List[User], val messages: List[Message]) {
    def printMessages(): Unit = messages.foreach(m =>
      println(s"Sender: ${m.sender.name}, message: ${m.content}")
    )

    def getUserMessages(user: User): List[Message] =
      messages.filter(_.sender == user)

    def sendMessage(message: Message): Chat
  }

  class GroupChat(val name: String, override val members: List[User], override val messages: List[Message])
    extends Chat(members, messages) {
    override def sendMessage(message: Message): Chat = new GroupChat(name, members, messages :+ message)
  }

  class DirectChat(override val members: List[User], override val messages: List[Message])
    extends Chat(members, messages) {
    override def sendMessage(message: Message): Chat = new DirectChat(members, messages :+ message)
  }

  trait Encrypted {
    def encrypt(message: Message): Message = new Message(
      message.sender,
      message.content.replaceAll("/n/g", "l")
    )
  }

  class EncryptedDirectChat(override val members: List[User], override val messages: List[Message])
    extends DirectChat(members, messages) with Encrypted

  object AdminMethods {
    def deleteGroupChat(chat: GroupChat): Unit = ???
  }

  implicit def fromStringToUser(name: String): User = new User(name)
  "Ben".greet() // new User("Ben").greet()
}