/*  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, ByteArrayOutputStream}

 import javax.swing.text.Segment

 import scala.util.parsing.input.Reader

 import org.gjt.sp.jedit.io.{VFS, FileVFS, 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],

     known_theories: Map[String, Document.Node.Name],

     base_syntax: Outer_Syntax)

   extends Resources(loaded_theories, known_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 if (path.is_current) dir

     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_reader[A](name: Document.Node.Name, f: Reader[Char] => A): A =

   {

     Swing_Thread.now {

       JEdit_Lib.jedit_buffer(name) match {

         case Some(buffer) =>

           JEdit_Lib.buffer_lock(buffer) { Some(f(JEdit_Lib.buffer_reader(buffer))) }

         case None => None

       }

     } getOrElse {

       if (Url.is_wellformed(name.node)) f(Scan.byte_reader(Url(name.node)))

       else {

         val file = new JFile(name.node)

         if (file.isFile) f(Scan.byte_reader(file))

         else error("No such file: " + quote(file.toString))

       }

     }

   }

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

     try {

       if (Url.is_wellformed(file)) Url.is_readable(file)

       else (new JFile(file)).isFile

     }

     catch { case ERROR(_) => false }

   /* file content */

   private class File_Content_Output(buffer: Buffer) extends

     ByteArrayOutputStream(buffer.getLength + 1)

   {

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

   }

   private class File_Content(buffer: Buffer) extends

     BufferIORequest(null, buffer, null, VFSManager.getVFSForPath(buffer.getPath), buffer.getPath)

   {

     def _run() { }

     def content(): Bytes =

     {

       val out = new File_Content_Output(buffer)

       write(buffer, out)

       out.content()

     }

   }

   def file_content(buffer: Buffer): Bytes = (new File_Content(buffer)).content()

   /* theory text edits */

   override def commit(change: Session.Change)

   {

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

   }

 }