/*  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.actors.Actor._

import java.lang.System

import java.awt.{BorderLayout, Graphics, Color, Dimension, Graphics2D, Point}

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

  FocusAdapter, FocusEvent, WindowEvent, WindowAdapter}

import javax.swing.{JPanel, ToolTipManager, 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 */

  // simplify slightly odd result of TextArea.getScreenLineEndOffset etc.

  // NB: jEdit already normalizes \r\n and \r to \n

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

  {

    val stop = if (start < end) end - 1 else end min model.buffer.getLength

    Text.Range(start, stop)

  }

  def visible_range(): Text.Range =

  {

    val start = text_area.getScreenLineStartOffset(0)

    val raw_end = text_area.getScreenLineEndOffset(text_area.getVisibleLines - 1 max 0)

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

  }

  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 = Text.Range(0, (model.buffer.getLength - 1) max 0)

    Text.Perspective(

      for {

        i <- 0 until text_area.getVisibleLines

        val start = text_area.getScreenLineStartOffset(i)

        val stop = text_area.getScreenLineEndOffset(i)

        if start >= 0 && stop >= 0

        val 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_Markup.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 */

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

    : Option[(Text.Range, Color)] =

  {

    val offset = text_area.xyToOffset(x, y)

    snapshot.select_markup(Text.Range(offset, offset + 1))(Isabelle_Markup.subexp) match {

      case Text.Info(_, Some((range, color))) #:: _ => Some((snapshot.convert(range), color))

      case _ => None

    }

  }

  @volatile private var _highlight_range: Option[(Text.Range, Color)] = None

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

  /* CONTROL-mouse management */

  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) {

      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.swing_buffer_lock(model.buffer) {

          val snapshot = update_snapshot()

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

          _highlight_range map { case (range, _) => invalidate_range(range) }

          _highlight_range = if (control) subexp_range(snapshot, x, y) else None

          _highlight_range map { case (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)

        if (control) {

          snapshot.select_markup(Text.Range(offset, offset + 1))(Isabelle_Markup.tooltip) match

          {

            case Text.Info(_, Some(text)) #:: _ => Isabelle.tooltip(text)

            case _ => null

          }

        }

        else {

          // FIXME snapshot.cumulate

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

          {

            case Text.Info(_, Some(text)) #:: _ => Isabelle.tooltip(text)

            case _ => 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(()) {

        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.swing_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

                val icons =

                  (for (Text.Info(_, Some(icon)) <- // FIXME snapshot.cumulate

                    snapshot.select_markup(line_range)(Isabelle_Markup.gutter_message).iterator)

                  yield icon).toList.sortWith(_ >= _)

                icons match {

                  case icon :: _ =>

                    val icn = icon.icon

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

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

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

                  case Nil =>

                }

              }

            }

          }

        }

      }

    }

  }

  /* 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.proper_command_at(text_area.getCaretPosition)

  }

  private val caret_listener = new CaretListener {

    private val delay = Swing_Thread.delay_last(session.input_delay) {

      session.perspective.event(Session.Perspective)

    }

    override def caretUpdate(e: CaretEvent) { delay() }

  }

  /* overview of command status left of scrollbar */

  private val overview = new JPanel(new BorderLayout)

  {

    private val WIDTH = 10

    private val HEIGHT = 2

    setPreferredSize(new Dimension(WIDTH, 0))

    setRequestFocusEnabled(false)

    addMouseListener(new MouseAdapter {

      override def mousePressed(event: MouseEvent) {

        val line = y_to_line(event.getY)

        if (line >= 0 && line < text_area.getLineCount)

          text_area.setCaretPosition(text_area.getLineStartOffset(line))

      }

    })

    override def addNotify() {

      super.addNotify()

      ToolTipManager.sharedInstance.registerComponent(this)

    }

    override def removeNotify() {

      ToolTipManager.sharedInstance.unregisterComponent(this)

      super.removeNotify

    }

    override def paintComponent(gfx: Graphics)

    {

      super.paintComponent(gfx)

      Swing_Thread.assert()

      val buffer = model.buffer

      Isabelle.buffer_lock(buffer) {

        val snapshot = update_snapshot()

        def line_range(command: Command, start: Text.Offset): Option[(Int, Int)] =

        {

          try {

            val line1 = buffer.getLineOfOffset(snapshot.convert(start))

            val line2 = buffer.getLineOfOffset(snapshot.convert(start + command.length)) + 1

            Some((line1, line2))

          }

          catch { case e: ArrayIndexOutOfBoundsException => None }

        }

        for {

          (command, start) <- snapshot.node.command_starts

          if !command.is_ignored

          (line1, line2) <- line_range(command, start)

          val y = line_to_y(line1)

          val height = HEIGHT * (line2 - line1)

          color <- Isabelle_Markup.overview_color(snapshot, command)

        } {

          gfx.setColor(color)

          gfx.fillRect(0, y, getWidth - 1, height)

        }

      }

    }

    private def line_to_y(line: Int): Int =

      (line * getHeight) / (text_area.getBuffer.getLineCount max text_area.getVisibleLines)

    private def y_to_line(y: Int): Int =

      (y * (text_area.getBuffer.getLineCount max text_area.getVisibleLines)) / getHeight

  }

  /* main actor */

  private val main_actor = actor {

    loop {

      react {

        case Session.Commands_Changed(changed) =>

          val buffer = model.buffer

          Isabelle.swing_buffer_lock(buffer) {

            val (updated, snapshot) = flush_snapshot()

            val visible = visible_range()

            if (updated || changed.exists(snapshot.node.commands.contains))

              overview.repaint()

            if (updated) invalidate_range(visible)

            else {

              val visible_cmds =

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

              if (visible_cmds.exists(changed)) {

                for {

                  line <- 0 until text_area.getVisibleLines

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

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

                  val range = proper_line_range(start, end)

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

                  if line_cmds.exists(changed)

                } text_area.invalidateScreenLineRange(line, line)

              }

            }

          }

        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)

    text_area.removeLeftOfScrollBar(overview)

    text_area.getGutter.removeExtension(gutter_painter)

    text_area_painter.deactivate()

    painter.removeExtension(tooltip_painter)

    painter.removeExtension(update_perspective)

    exit_popup()

  }

}