/*  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()

  }

}