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

    Author:     Makarius

Resources for theories and auxiliary files, based on jEdit buffer

content and virtual file-systems.

*/

package isabelle.jedit

import isabelle._

import java.io.{File => JFile, IOException, ByteArrayOutputStream}

import javax.swing.text.Segment

import org.gjt.sp.jedit.io.{VFS, FileVFS, VFSFile, VFSManager}

import org.gjt.sp.jedit.MiscUtilities

import org.gjt.sp.jedit.{jEdit, View, Buffer}

import org.gjt.sp.jedit.bufferio.BufferIORequest

class JEdit_Resources(loaded_theories: Set[String] = Set.empty, base_syntax: Outer_Syntax)

  extends Resources(loaded_theories, base_syntax)

{

  /* document node names */

  def node_name(buffer: Buffer): Document.Node.Name =

  {

    val node = JEdit_Lib.buffer_name(buffer)

    val theory = Thy_Header.thy_name(node).getOrElse("")

    val master_dir = if (theory == "") "" else buffer.getDirectory

    Document.Node.Name(node, master_dir, theory)

  }

  def theory_node_name(buffer: Buffer): Option[Document.Node.Name] =

  {

    val name = node_name(buffer)

    if (name.is_theory) Some(name) else None

  }

  /* file-system operations */

  override def append(dir: String, source_path: Path): String =

  {

    val path = source_path.expand

    if (dir == "" || path.is_absolute) Isabelle_System.platform_path(path)

    else {

      val vfs = VFSManager.getVFSForPath(dir)

      if (vfs.isInstanceOf[FileVFS])

        MiscUtilities.resolveSymlinks(

          vfs.constructPath(dir, Isabelle_System.platform_path(path)))

      else vfs.constructPath(dir, Isabelle_System.standard_path(path))

    }

  }

  override def with_thy_text[A](name: Document.Node.Name, f: CharSequence => A): A =

  {

    Swing_Thread.now {

      JEdit_Lib.jedit_buffer(name) match {

        case Some(buffer) =>

          JEdit_Lib.buffer_lock(buffer) {

            Some(f(buffer.getSegment(0, buffer.getLength)))

          }

        case None => None

      }

    } getOrElse {

      val file = new JFile(name.node)  // FIXME load URL via jEdit VFS (!?)

      if (!file.exists || !file.isFile) error("No such file: " + quote(file.toString))

      f(File.read(file))

    }

  }

  def check_file(view: View, path: String): Boolean =

  {

    val vfs = VFSManager.getVFSForPath(path)

    val session = vfs.createVFSSession(path, view)

    try {

      session != null && {

        try {

          val file = vfs._getFile(session, path, view)

          file != null && file.isReadable && file.getType == VFSFile.FILE

        }

        catch { case _: IOException => false }

      }

    }

    finally {

      try { vfs._endVFSSession(session, view) }

      catch { case _: IOException => }

    }

  }

  /* file content */

  def file_content(buffer: Buffer): Bytes =

  {

    val path = buffer.getPath

    val vfs = VFSManager.getVFSForPath(path)

    val content =

      new BufferIORequest(null, buffer, null, vfs, path) {

        def _run() { }

        def apply(): Bytes =

        {

          val out =

            new ByteArrayOutputStream(buffer.getLength + 1) {

              def content(): Bytes = Bytes(this.buf, 0, this.count)

            }

          write(buffer, out)

          out.content()

        }

      }

    content()

  }

  /* theory text edits */

  override def commit(change: Session.Change)

  {

    if (change.syntax_changed) Swing_Thread.later { jEdit.propertiesChanged() }

    if (change.deps_changed) PIDE.deps_changed()

  }

}