/*  Title:      Pure/PIDE/command.scala

    Author:     Johannes Hölzl, TU Munich

    Author:     Fabian Immler, TU Munich

    Author:     Makarius

Prover commands with semantic state.

*/

package isabelle

import scala.actors.Actor, Actor._

import scala.collection.mutable

object Command

{

  object Status extends Enumeration

  {

    val UNPROCESSED = Value("UNPROCESSED")

    val FINISHED = Value("FINISHED")

    val FAILED = Value("FAILED")

  }

  case class HighlightInfo(highlight: String) { override def toString = highlight }

  case class TypeInfo(ty: String)

  case class RefInfo(file: Option[String], line: Option[Int],

    command_id: Option[String], offset: Option[Int])

}

class Command(

    val id: Isar_Document.Command_ID,

    val span: Thy_Syntax.Span)

  extends Session.Entity

{

  /* classification */

  def is_command: Boolean = !span.isEmpty && span.head.is_command

  def is_ignored: Boolean = span.forall(_.is_ignored)

  def is_malformed: Boolean = !is_command && !is_ignored

  def name: String = if (is_command) span.head.content else ""

  override def toString = if (is_command) name else if (is_ignored) "<ignored>" else "<malformed>"

  /* source text */

  val source: String = span.map(_.source).mkString

  def source(i: Int, j: Int): String = source.substring(i, j)

  def length: Int = source.length

  lazy val symbol_index = new Symbol.Index(source)

  /* accumulated messages */

  @volatile protected var state = new State(this)

  def current_state: State = state

  private case class Consume(session: Session, message: XML.Tree)

  private case object Assign

  private val accumulator = actor {

    var assigned = false

    loop {

      react {

        case Consume(session: Session, message: XML.Tree) if !assigned =>

          state = state.+(session, message)

        case Assign =>

          assigned = true  // single assignment

          reply(())

        case bad => System.err.println("command accumulator: ignoring bad message " + bad)

      }

    }

  }

  def consume(session: Session, message: XML.Tree) { accumulator ! Consume(session, message) }

  def assign_state(state_id: Isar_Document.State_ID): Command =

  {

    val cmd = new Command(state_id, span)

    accumulator !? Assign

    cmd.state = current_state

    cmd

  }

  /* markup */

  lazy val empty_markup = new Markup_Text(Nil, source)

  def markup_node(begin: Int, end: Int, info: Any): Markup_Tree =

  {

    val start = symbol_index.decode(begin)

    val stop = symbol_index.decode(end)

    new Markup_Tree(new Markup_Node(start, stop, info), Nil)

  }

}