/*

 * Scala instance of Console plugin

 *

 * @author Makarius

 */

package isabelle.jedit

import console.{Console, ConsolePane, Shell, Output}

import org.gjt.sp.jedit.{jEdit, JARClassLoader}

import org.gjt.sp.jedit.MiscUtilities

import java.io.{File, Writer, PrintWriter}

import scala.tools.nsc.{Interpreter, GenericRunnerSettings, NewLinePrintWriter, ConsoleWriter}

import scala.collection.mutable

class Scala_Console extends Shell("Scala")

{

  private var interpreters = Map[Console, Interpreter]()

  private var global_console: Console = null

  private var global_out: Output = null

  private var global_err: Output = null

  private def with_console[A](console: Console, out: Output, err: Output)(e: => A): A =

  {

    global_console = console

    global_out = out

    global_err = if (err == null) out else err

    val res = Exn.capture { e }

    global_console = null

    global_out = null

    global_err = null

    Exn.release(res)

  }

  private def report_error(str: String)

  {

    if (global_console == null || global_err == null) System.err.println(str)

    else global_err.print(global_console.getErrorColor, str)

  }

  private def construct_classpath(): String =

  {

    def find_jars(start: String): List[String] =

      if (start != null)

        Standard_System.find_files(new File(start),

          entry => entry.isFile && entry.getName.endsWith(".jar")).map(_.getAbsolutePath)

      else Nil

    val path =

      (jEdit.getJEditHome + File.separator + "jedit.jar") ::

        (find_jars(jEdit.getSettingsDirectory) ::: find_jars(jEdit.getJEditHome))

     path.mkString(File.pathSeparator)

  }

  private class Console_Writer extends Writer

  {

    def close {}

    def flush {}

    def write(cbuf: Array[Char], off: Int, len: Int)

    {

      if (len > 0) write(new String(cbuf.subArray(off, off + len)))

    }

    override def write(str: String)

    {

      if (global_out == null) System.out.println(str)

      else global_out.print(null, str)

    }

  }

  override def openConsole(console: Console)

  {

    val settings = new GenericRunnerSettings(report_error)

    settings.classpath.value = construct_classpath()

    val printer = new PrintWriter(new Console_Writer, true)

    val interp = new Interpreter(settings, printer)

    {

      override def parentClassLoader = new JARClassLoader

    }

    interp.setContextClassLoader

    interp.bind("view", "org.gjt.sp.jedit.View", console.getView)

    interpreters += (console -> interp)

  }

  override def closeConsole(console: Console)

  {

    interpreters -= console

  }

  override def printPrompt(console: Console, out: Output)

	{

    out.writeAttrs(ConsolePane.colorAttributes(console.getInfoColor), "scala>")

		out.writeAttrs(ConsolePane.colorAttributes(console.getPlainColor), " ")

	}

  override def execute(console: Console, input: String, out: Output, err: Output, command: String)

  {

    val interp = interpreters(console)

    with_console(console, out, err) { interp.interpret(command) }

    if (err != null) err.commandDone()

		out.commandDone()

  }

}