/*  Title:      Tools/jEdit/src/isabelle_encoding.scala

    Author:     Makarius

Isabelle encoding -- based on UTF-8.

*/

package isabelle.jedit

import isabelle._

import org.gjt.sp.jedit.io.Encoding

import org.gjt.sp.jedit.buffer.JEditBuffer

import java.nio.charset.{Charset, CodingErrorAction}

import java.io.{InputStream, OutputStream, Reader, Writer, InputStreamReader, OutputStreamWriter,

  CharArrayReader, ByteArrayOutputStream}

import scala.io.{Codec, Source, BufferedSource}

object Isabelle_Encoding

{

  val NAME = "UTF-8-Isabelle"

  def is_active(buffer: JEditBuffer): Boolean =

    buffer.getStringProperty(JEditBuffer.ENCODING).asInstanceOf[String] == NAME

}

class Isabelle_Encoding extends Encoding

{

  private val BUFSIZE = 32768

  private def text_reader(in: InputStream, codec: Codec): Reader =

  {

    val source = new BufferedSource(in)(codec)

    new CharArrayReader(Symbol.decode(source.mkString).toArray)

  }

  override def getTextReader(in: InputStream): Reader =

    text_reader(in, Standard_System.codec())

  override def getPermissiveTextReader(in: InputStream): Reader =

  {

    val codec = Standard_System.codec()

    codec.onMalformedInput(CodingErrorAction.REPLACE)

    codec.onUnmappableCharacter(CodingErrorAction.REPLACE)

    text_reader(in, codec)

  }

  override def getTextWriter(out: OutputStream): Writer =

  {

    val buffer = new ByteArrayOutputStream(BUFSIZE) {

      override def flush()

      {

        val text = Symbol.encode(toString(Standard_System.charset_name))

        out.write(text.getBytes(Standard_System.charset))

        out.flush()

      }

      override def close() { out.close() }

    }

    new OutputStreamWriter(buffer, Standard_System.charset.newEncoder())

  }

}