// SPDX-License-Identifier: Apache-2.0

package firrtl.passes

import firrtl._
import firrtl.ir._
import firrtl.Mappers._
import firrtl.traversals.Foreachers._

object ResolveKinds extends Pass {

  override def prerequisites = firrtl.stage.Forms.WorkingIR

  override def invalidates(a: Transform) = false

  type KindMap = collection.mutable.HashMap[String, Kind]

  private def find_port(kinds: KindMap)(p: Port): Unit = {
    kinds(p.name) = PortKind
  }

  def resolve_expr(kinds: KindMap)(e: Expression): Expression = e match {
    case ex: WRef => ex.copy(kind = kinds(ex.name))
    case _ => e.map(resolve_expr(kinds))
  }

  def resolve_stmt(kinds: KindMap)(s: Statement): Statement = {
    s match {
      case sx: DefWire      => kinds(sx.name) = WireKind
      case sx: DefNode      => kinds(sx.name) = NodeKind
      case sx: DefRegister  => kinds(sx.name) = RegKind
      case sx: WDefInstance => kinds(sx.name) = InstanceKind
      case sx: DefMemory    => kinds(sx.name) = MemKind
      case _ =>
    }
    s.map(resolve_stmt(kinds))
      .map(resolve_expr(kinds))
  }

  def resolve_kinds(m: DefModule): DefModule = {
    val kinds = new KindMap
    m.foreach(find_port(kinds))
    m.map(resolve_stmt(kinds))
  }

  def run(c: Circuit): Circuit =
    c.copy(modules = c.modules.map(resolve_kinds))
}
