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

     Author:     Fabian Immler, TU Munich

     Author:     Makarius

 Document view connected to jEdit text area.

 */

 package isabelle.jedit

 import isabelle._

 import scala.collection.mutable

 import scala.collection.immutable.SortedMap

 import scala.actors.Actor._

 import java.lang.System

 import java.text.BreakIterator

 import java.awt.{Color, Graphics2D, Point}

 import java.awt.event.{MouseMotionAdapter, MouseEvent,

   FocusAdapter, FocusEvent, WindowEvent, WindowAdapter}

 import javax.swing.{Popup, PopupFactory, SwingUtilities, BorderFactory}

 import javax.swing.event.{CaretListener, CaretEvent}

 import org.gjt.sp.util.Log

 import org.gjt.sp.jedit.{jEdit, OperatingSystem, Debug}

 import org.gjt.sp.jedit.gui.RolloverButton

 import org.gjt.sp.jedit.options.GutterOptionPane

 import org.gjt.sp.jedit.textarea.{JEditTextArea, TextArea, TextAreaExtension, TextAreaPainter,

   ScrollListener}

 import org.gjt.sp.jedit.syntax.{SyntaxStyle}

 object Document_View

 {

   /* document view of text area */

   private val key = new Object

   def apply(text_area: JEditTextArea): Option[Document_View] =

   {

     Swing_Thread.require()

     text_area.getClientProperty(key) match {

       case doc_view: Document_View => Some(doc_view)

       case _ => None

     }

   }

   def exit(text_area: JEditTextArea)

   {

     Swing_Thread.require()

     apply(text_area) match {

       case None =>

       case Some(doc_view) =>

         doc_view.deactivate()

         text_area.putClientProperty(key, null)

     }

   }

   def init(model: Document_Model, text_area: JEditTextArea): Document_View =

   {

     exit(text_area)

     val doc_view = new Document_View(model, text_area)

     text_area.putClientProperty(key, doc_view)

     doc_view.activate()

     doc_view

   }

 }

 class Document_View(val model: Document_Model, val text_area: JEditTextArea)

 {

   private val session = model.session

   /* robust extension body */

   def robust_body[A](default: A)(body: => A): A =

   {

     try {

       Swing_Thread.require()

       if (model.buffer == text_area.getBuffer) body

       else {

         Log.log(Log.ERROR, this, ERROR("Inconsistent document model"))

         default

       }

     }

     catch { case t: Throwable => Log.log(Log.ERROR, this, t); default }

   }

   /* visible text range */

   // NB: TextArea.getScreenLineEndOffset of last line is beyond Buffer.getLength

   def proper_line_range(start: Text.Offset, end: Text.Offset): Text.Range =

     Text.Range(start, end min model.buffer.getLength)

   def visible_range(): Option[Text.Range] =

   {

     val n = text_area.getVisibleLines

     if (n > 0) {

       val start = text_area.getScreenLineStartOffset(0)

       val raw_end = text_area.getScreenLineEndOffset(n - 1)

       Some(proper_line_range(start, if (raw_end >= 0) raw_end else model.buffer.getLength))

     }

     else None

   }

   def invalidate_range(range: Text.Range)

   {

     text_area.invalidateLineRange(

       model.buffer.getLineOfOffset(range.start),

       model.buffer.getLineOfOffset(range.stop))

   }

   /* perspective */

   def perspective(): Text.Perspective =

   {

     Swing_Thread.require()

     val buffer_range = model.buffer_range()

     Text.Perspective(

       for {

         i <- 0 until text_area.getVisibleLines

         start = text_area.getScreenLineStartOffset(i)

         stop = text_area.getScreenLineEndOffset(i)

         if start >= 0 && stop >= 0

         range <- buffer_range.try_restrict(Text.Range(start, stop))

         if !range.is_singularity

       }

       yield range)

   }

   private def update_perspective = new TextAreaExtension

   {

     override def paintScreenLineRange(gfx: Graphics2D,

       first_line: Int, last_line: Int, physical_lines: Array[Int],

       start: Array[Int], end: Array[Int], y: Int, line_height: Int)

     {

       model.update_perspective()

     }

   }

   /* snapshot */

   // owned by Swing thread

   @volatile private var was_outdated = false

   @volatile private var was_updated = false

   def update_snapshot(): Document.Snapshot =

   {

     Swing_Thread.require()

     val snapshot = model.snapshot()

     was_updated = was_outdated && !snapshot.is_outdated

     was_outdated = was_outdated || snapshot.is_outdated

     snapshot

   }

   def flush_snapshot(): (Boolean, Document.Snapshot) =

   {

     Swing_Thread.require()

     val snapshot = update_snapshot()

     val updated = was_updated

     if (updated) { was_outdated = false; was_updated = false }

     (updated, snapshot)

   }

   /* HTML popups */

   private var html_popup: Option[Popup] = None

   private def exit_popup() { html_popup.map(_.hide) }

   private val html_panel =

     new HTML_Panel(Isabelle.font_family(), scala.math.round(Isabelle.font_size()))

   html_panel.setBorder(BorderFactory.createLineBorder(Color.black))

   private def html_panel_resize()

   {

     Swing_Thread.now {

       html_panel.resize(Isabelle.font_family(), scala.math.round(Isabelle.font_size()))

     }

   }

   private def init_popup(snapshot: Document.Snapshot, x: Int, y: Int)

   {

     exit_popup()

 /* FIXME broken

     val offset = text_area.xyToOffset(x, y)

     val p = new Point(x, y); SwingUtilities.convertPointToScreen(p, text_area.getPainter)

     // FIXME snapshot.cumulate

     snapshot.select_markup(Text.Range(offset, offset + 1))(Isabelle_Rendering.popup) match {

       case Text.Info(_, Some(msg)) #:: _ =>

         val popup = PopupFactory.getSharedInstance().getPopup(text_area, html_panel, p.x, p.y + 60)

         html_panel.render_sync(List(msg))

         Thread.sleep(10)  // FIXME !?

         popup.show

         html_popup = Some(popup)

       case _ =>

     }

 */

   }

   /* subexpression highlighting */

   @volatile private var _highlight_range: Option[Text.Info[Color]] = None

   def highlight_range(): Option[Text.Info[Color]] = _highlight_range

   private var control: Boolean = false

   private def exit_control()

   {

     exit_popup()

     _highlight_range = None

   }

   private val focus_listener = new FocusAdapter {

     override def focusLost(e: FocusEvent) {

       _highlight_range = None // FIXME exit_control !?

     }

   }

   private val window_listener = new WindowAdapter {

     override def windowIconified(e: WindowEvent) { exit_control() }

     override def windowDeactivated(e: WindowEvent) { exit_control() }

   }

   private val mouse_motion_listener = new MouseMotionAdapter {

     override def mouseMoved(e: MouseEvent) {

       Swing_Thread.assert()

       control = if (OperatingSystem.isMacOS()) e.isMetaDown else e.isControlDown

       val x = e.getX()

       val y = e.getY()

       if (!model.buffer.isLoaded) exit_control()

       else

         Isabelle.buffer_lock(model.buffer) {

           val snapshot = update_snapshot()

           if (control) init_popup(snapshot, x, y)

           for (Text.Info(range, _) <- _highlight_range) invalidate_range(range)

           _highlight_range =

             if (control) {

               val offset = text_area.xyToOffset(x, y)

               Isabelle_Rendering.subexp(snapshot, Text.Range(offset, offset + 1))

             }

             else None

           for (Text.Info(range, _) <- _highlight_range) invalidate_range(range)

         }

     }

   }

   /* text area painting */

   private val text_area_painter = new Text_Area_Painter(this)

   private val tooltip_painter = new TextAreaExtension

   {

     override def getToolTipText(x: Int, y: Int): String =

     {

       robust_body(null: String) {

         val snapshot = update_snapshot()

         val offset = text_area.xyToOffset(x, y)

         val range = Text.Range(offset, offset + 1)

         val tip =

           if (control) Isabelle_Rendering.tooltip(snapshot, range)

           else Isabelle_Rendering.tooltip_message(snapshot, range)

         tip.map(Isabelle.tooltip(_)) getOrElse null

       }

     }

   }

   private val gutter_painter = new TextAreaExtension

   {

     override def paintScreenLineRange(gfx: Graphics2D,

       first_line: Int, last_line: Int, physical_lines: Array[Int],

       start: Array[Int], end: Array[Int], y: Int, line_height: Int)

     {

       robust_body(()) {

         Swing_Thread.assert()

         val gutter = text_area.getGutter

         val width = GutterOptionPane.getSelectionAreaWidth

         val border_width = jEdit.getIntegerProperty("view.gutter.borderWidth", 3)

         val FOLD_MARKER_SIZE = 12

         if (gutter.isSelectionAreaEnabled && !gutter.isExpanded && width >= 12 && line_height >= 12) {

           Isabelle.buffer_lock(model.buffer) {

             val snapshot = update_snapshot()

             for (i <- 0 until physical_lines.length) {

               if (physical_lines(i) != -1) {

                 val line_range = proper_line_range(start(i), end(i))

                 // gutter icons

                 Isabelle_Rendering.gutter_message(snapshot, line_range) match {

                   case Some(icon) =>

                     val x0 = (FOLD_MARKER_SIZE + width - border_width - icon.getIconWidth) max 10

                     val y0 = y + i * line_height + (((line_height - icon.getIconHeight) / 2) max 0)

                     icon.paintIcon(gutter, gfx, x0, y0)

                   case None =>

                 }

               }

             }

           }

         }

       }

     }

   }

   /* caret range */

   def caret_range(): Text.Range =

     Isabelle.buffer_lock(model.buffer) {

       def text(i: Text.Offset): Char = model.buffer.getText(i, 1).charAt(0)

       val caret = text_area.getCaretPosition

       try {

         val c = text(caret)

         if (Character.isHighSurrogate(c) && Character.isLowSurrogate(text(caret + 1)))

           Text.Range(caret, caret + 2)

         else if (Character.isLowSurrogate(c) && Character.isHighSurrogate(text(caret - 1)))

           Text.Range(caret - 1, caret + 1)

         else Text.Range(caret, caret + 1)

       }

       catch { case _: ArrayIndexOutOfBoundsException => Text.Range(caret, caret + 1) }

     }

   /* caret handling */

   def selected_command(): Option[Command] =

   {

     Swing_Thread.require()

     update_snapshot().node.command_at(text_area.getCaretPosition).map(_._1)

   }

   private val delay_caret_update =

     Swing_Thread.delay_last(session.input_delay) {

       session.caret_focus.event(Session.Caret_Focus)

     }

   private val caret_listener = new CaretListener {

     override def caretUpdate(e: CaretEvent) { delay_caret_update(true) }

   }

   /* text status overview left of scrollbar */

   private val overview = new Text_Overview(this)

   {

     val delay_repaint =

       Swing_Thread.delay_first(Isabelle.session.update_delay) { repaint() }

   }

   /* main actor */

   private val main_actor = actor {

     loop {

       react {

         case changed: Session.Commands_Changed =>

           val buffer = model.buffer

           Swing_Thread.later {

             Isabelle.buffer_lock(buffer) {

               if (model.buffer == text_area.getBuffer) {

                 val (updated, snapshot) = flush_snapshot()

                 if (updated ||

                     (changed.nodes.contains(model.name) &&

                      changed.commands.exists(snapshot.node.commands.contains)))

                   overview.delay_repaint(true)

                 visible_range() match {

                   case Some(visible) =>

                     if (updated) invalidate_range(visible)

                     else {

                       val visible_cmds =

                         snapshot.node.command_range(snapshot.revert(visible)).map(_._1)

                       if (visible_cmds.exists(changed.commands)) {

                         for {

                           line <- 0 until text_area.getVisibleLines

                           start = text_area.getScreenLineStartOffset(line) if start >= 0

                           end = text_area.getScreenLineEndOffset(line) if end >= 0

                           range = proper_line_range(start, end)

                           line_cmds = snapshot.node.command_range(snapshot.revert(range)).map(_._1)

                           if line_cmds.exists(changed.commands)

                         } text_area.invalidateScreenLineRange(line, line)

                       }

                     }

                   case None =>

                 }

               }

             }

           }

         case Session.Global_Settings => html_panel_resize()

         case bad => System.err.println("command_change_actor: ignoring bad message " + bad)

       }

     }

   }

   /* activation */

   private def activate()

   {

     val painter = text_area.getPainter

     painter.addExtension(TextAreaPainter.LOWEST_LAYER, update_perspective)

     painter.addExtension(TextAreaPainter.LINE_BACKGROUND_LAYER + 1, tooltip_painter)

     text_area_painter.activate()

     text_area.getGutter.addExtension(gutter_painter)

     text_area.addFocusListener(focus_listener)

     text_area.getView.addWindowListener(window_listener)

     painter.addMouseMotionListener(mouse_motion_listener)

     text_area.addCaretListener(caret_listener)

     text_area.addLeftOfScrollBar(overview)

     session.commands_changed += main_actor

     session.global_settings += main_actor

   }

   private def deactivate()

   {

     val painter = text_area.getPainter

     session.commands_changed -= main_actor

     session.global_settings -= main_actor

     text_area.removeFocusListener(focus_listener)

     text_area.getView.removeWindowListener(window_listener)

     painter.removeMouseMotionListener(mouse_motion_listener)

     text_area.removeCaretListener(caret_listener); delay_caret_update(false)

     text_area.removeLeftOfScrollBar(overview); overview.delay_repaint(false)

     text_area.getGutter.removeExtension(gutter_painter)

     text_area_painter.deactivate()

     painter.removeExtension(tooltip_painter)

     painter.removeExtension(update_perspective)

     exit_popup()

   }

 }