src/Tools/jEdit/src/proofdocument/session.scala

register Proof_Document instances as session entities -- handle Markup.EDIT messages locally;

/*
 * Isabelle session, potentially with running prover
 *
 * @author Makarius
 */

package isabelle.proofdocument


import scala.actors.Actor._


object Session
{
  /* events */

  case object Global_Settings


  /* managed entities */

  type Entity_ID = String

  trait Entity
  {
    val id: Entity_ID
    def consume(session: Session, message: XML.Tree): Unit
  }
}


class Session(system: Isabelle_System)
{
  /* pervasive event buses */

  val global_settings = new Event_Bus[Session.Global_Settings.type]
  val raw_results = new Event_Bus[Isabelle_Process.Result]
  val results = new Event_Bus[Command]

  val command_change = new Event_Bus[Command]
  val document_change = new Event_Bus[Proof_Document]


  /* unique ids */

  private var id_count: BigInt = 0
  def create_id(): Session.Entity_ID = synchronized { id_count += 1; "j" + id_count }


  /* document state information -- owned by session_actor */

  @volatile private var outer_syntax = new Outer_Syntax(system.symbols)
  def syntax(): Outer_Syntax = outer_syntax

  @volatile private var entities = Map[Session.Entity_ID, Session.Entity]()
  def lookup_entity(id: Session.Entity_ID): Option[Session.Entity] = entities.get(id)

  // FIXME eliminate
  @volatile private var documents = Map[Isar_Document.Document_ID, Proof_Document]()
  def document(id: Isar_Document.Document_ID): Option[Proof_Document] = documents.get(id)



  /** main actor **/

  private case class Register(entity: Session.Entity)
  private case class Start(args: List[String])
  private case object Stop
  private case class Begin_Document(path: String)

  private val session_actor = actor {

    var prover: Isabelle_Process with Isar_Document = null
    var prover_ready = false

    def register(entity: Session.Entity) { entities += (entity.id -> entity) }


    /* document changes */

    def handle_change(change: Change)
    {
      val old = document(change.parent.get.id).get
      val (doc, changes) = old.text_changed(this, change)

      val id_changes = changes map {
        case (c1, c2) =>
          (c1.map(_.id).getOrElse(""),
           c2 match {
              case None => None
              case Some(command) =>  // FIXME clarify -- may reuse existing commands!??
                register(command)
                prover.define_command(command.id, system.symbols.encode(command.content))
                Some(command.id)
            })
      }
      register(doc)
      documents += (doc.id -> doc)
      prover.edit_document(old.id, doc.id, id_changes)

      document_change.event(doc)
    }


    /* prover results */

    def handle_result(result: Isabelle_Process.Result)
    {
      raw_results.event(result)

      val target: Option[Session.Entity] =
        Position.get_id(result.props) match {
          case None => None
          case Some(id) => entities.get(id)
        }
      if (target.isDefined) target.get.consume(this, result.message)
      else if (result.kind == Isabelle_Process.Kind.STATUS) {
        // global status message
        for (elem <- result.body) {
          elem match {
            // command and keyword declarations
            case XML.Elem(Markup.COMMAND_DECL, (Markup.NAME, name) :: (Markup.KIND, kind) :: _, _) =>
              outer_syntax += (name, kind)
            case XML.Elem(Markup.KEYWORD_DECL, (Markup.NAME, name) :: _, _) =>
              outer_syntax += name

            // process ready (after initialization)
            case XML.Elem(Markup.READY, _, _) => prover_ready = true

          case _ =>
          }
        }
      }
      else if (result.kind == Isabelle_Process.Kind.EXIT)
        prover = null
    }

    val xml_cache = new XML.Cache(131071)


    /* main loop */

    loop {
      react {
        case Register(entity: Session.Entity) =>
          register(entity)
          reply(())

        case Start(args) =>
          if (prover == null) {
            prover = new Isabelle_Process(system, self, args:_*) with Isar_Document
            reply(())
          }

        case Stop =>  // FIXME clarify
          if (prover != null)
            prover.kill
          prover_ready = false

        case Begin_Document(path: String) if prover_ready =>
          val id = create_id()
          val doc = Proof_Document.empty(id)
          register(doc)
          documents += (id -> doc)
          prover.begin_document(id, path)
          reply(doc)

        case change: Change if prover_ready =>
          handle_change(change)

        case result: Isabelle_Process.Result =>
          handle_result(result.cache(xml_cache))

        case bad if prover_ready =>
          System.err.println("session_actor: ignoring bad message " + bad)
      }
    }
  }


  /* main methods */

  def register_entity(entity: Session.Entity) { session_actor !? Register(entity) }

  def start(args: List[String]) { session_actor !? Start(args) }
  def stop() { session_actor ! Stop }
  def input(change: Change) { session_actor ! change }

  def begin_document(path: String): Proof_Document =
    (session_actor !? Begin_Document(path)).asInstanceOf[Proof_Document]
}