modules.sc

trait Bindable {
  def label: String
}
case class Port(label: String) extends Bindable
case class Net(label: String) extends Bindable

case class Binding(from: Bindable, to: Bindable){
  override def toString: String = s"$from -> $to"
}

case class Instance(module: Module, bindings: Set[Binding])

trait Module {
  def ports(): Set[Port]
  def nets(): Set[Net]
  def instances(): Set[Instance]
}

object M1 extends Module {
  val x: Port = Port("x")
  val y: Port = Port("y")
  override def ports(): Set[Port] = Set(x, y)
  override def nets(): Set[Net] = Set.empty
  override def instances(): Set[Instance] = Set.empty
}

object M2 extends Module {
  val u: Port = Port("u")
  val v: Port = Port("v")
  val t: Net = Net("t")

  val i1: Instance = Instance(
    M1,
    Set(
      Binding(M1.x, u),
      Binding(M1.y, t)
    )
  )

  val i2: Instance = Instance(
    M1,
    Set(
      Binding(M1.x, t),
      Binding(M1.y, u)
    )
  )
  override def ports(): Set[Port] = Set(u, v)
  override def nets(): Set[Net] = Set(t)
  override def instances(): Set[Instance] = Set(i1, i2)
}

def traverseAndPrint(module: Module, level: Int = 0): Unit = {
  def printPadded(message: String) = println(s"${" ".repeat(level*2)}$message")
  printPadded(s"Module of type ${module.getClass.getSimpleName}")
  printPadded(s"Ports: ${module.ports()}")
  printPadded(s"Nets: ${module.nets()}")
  printPadded(s"Instances: ")
  if (module.instances().isEmpty) printPadded("- No instances")
  else {
    module.instances().foreach(i =>
      if(i.bindings.isEmpty) printPadded("- No Bindings")
      else printPadded(s"- Bindings: ${i.bindings.mkString("; ")}")
      traverseAndPrint(i.module, level + 1)
    )
  }
}

println("MODULE M1:")
traverseAndPrint(M1)
println("MODULE M2:")
traverseAndPrint(M2)