import chisel3._
import chisel3.experimental.{ChiselAnnotation, annotate}
import circt.stage.ChiselStage
import firrtl.AnnotationSeq
import firrtl.annotations.{ReferenceTarget, SingleTargetAnnotation}
import firrtl.options.CustomFileEmission

case class MyMetaString(target: ReferenceTarget, string: String, version: Float = 1.0f)
  extends SingleTargetAnnotation[ReferenceTarget]
	with CustomFileEmission {
  def targets = Seq(target)

  def duplicate(n: ReferenceTarget) = {
	println("duplicate")
	this.copy()
  }

  //def getBytes: Iterable[Byte] = string.getBytes
  protected def baseFileName(annotations: AnnotationSeq): String = "my_meta"

  protected def suffix: Option[String] = Some(".tvcd")

  def getBytes: Iterable[Byte] =
	s"Annotated signal: ${target.serialize} -> $string $version".getBytes
}

object mark {
  def apply[T <: Data](x: T): T = {
	annotate(new ChiselAnnotation {
	  def toFirrtl = MyMetaString(x.toTarget, x.pathName)
	})
	x
  }
}

class Foo extends Module {
  val in = IO(Input(UInt(3.W)))
  val out = IO(Output(UInt(2.W)))

  out := in
  mark(in)
}

object Main extends App {

  /* Run Chisel, but not the Scala FIRRTL Compiler. */
  println((ChiselStage).emitSystemVerilog(new Foo))
  ChiselStage.emitSystemVerilogFile(new Foo)


}