/*

  * Prover commands with semantic state

  *

  * @author Johannes Hölzl, TU Munich

  * @author Fabian Immler, TU Munich

  */

 package isabelle.proofdocument

 import scala.actors.Actor, Actor._

 import scala.collection.mutable

 import isabelle.jedit.Isabelle

 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.first.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.first.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)

   }

 }