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

    Author:     Fabian Immler, TU Munich

    Author:     Makarius

Document view connected to jEdit text area.

*/

package isabelle.jedit

import isabelle._

import scala.actors.Actor._

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

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

import javax.swing.{JPanel, ToolTipManager}

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

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

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

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

object Document_View

{

  def choose_color(snapshot: Document.Snapshot, command: Command): Color =

  {

    val state = snapshot.state(command)

    if (snapshot.is_outdated) new Color(240, 240, 240)

    else

      Isar_Document.command_status(state.status) match {

        case Isar_Document.Forked(i) if i > 0 => new Color(255, 228, 225)

        case Isar_Document.Finished => new Color(234, 248, 255)

        case Isar_Document.Failed => new Color(255, 193, 193)

        case Isar_Document.Unprocessed => new Color(255, 228, 225)

        case _ => Color.red

      }

  }

  /* document view of text area */

  private val key = new Object

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

  {

    Swing_Thread.require()

    val doc_view = new Document_View(model, text_area)

    text_area.putClientProperty(key, doc_view)

    doc_view.activate()

    doc_view

  }

  def apply(text_area: TextArea): 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: TextArea)

  {

    Swing_Thread.require()

    apply(text_area) match {

      case None => error("No document view for text area: " + text_area)

      case Some(doc_view) =>

        doc_view.deactivate()

        text_area.putClientProperty(key, null)

    }

  }

}

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

{

  private val session = model.session

  /* extended token styles */

  private var styles: Array[SyntaxStyle] = null  // owned by Swing thread

  def extend_styles()

  {

    Swing_Thread.require()

    styles = Document_Model.Token_Markup.extend_styles(text_area.getPainter.getStyles)

  }

  extend_styles()

  def set_styles()

  {

    Swing_Thread.require()

    text_area.getPainter.setStyles(styles)

  }

  /* visible line ranges */

  // 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 screen_lines_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)

  }

  /* commands_changed_actor */

  private val commands_changed_actor = actor {

    loop {

      react {

        case Session.Commands_Changed(changed) =>

          val buffer = model.buffer

          Isabelle.swing_buffer_lock(buffer) {

            val snapshot = model.snapshot()

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

              overview.repaint()

            val visible_range = screen_lines_range()

            val visible_cmds = snapshot.node.command_range(snapshot.revert(visible_range)).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)

              // FIXME danger of deadlock!?

              // FIXME potentially slow!?

              model.buffer.propertiesChanged()

            }

          }

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

      }

    }

  }

  /* text_area_extension */

  private val text_area_extension = new TextAreaExtension

  {

    override def paintScreenLineRange(gfx: Graphics2D,

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

      start: Array[Int], end: Array[Int], y0: Int, line_height: Int)

    {

      Isabelle.swing_buffer_lock(model.buffer) {

        val snapshot = model.snapshot()

        val saved_color = gfx.getColor

        try {

          var y = y0

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

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

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

              val cmds = snapshot.node.command_range(snapshot.revert(line_range))

              for ((command, command_start) <- cmds if !command.is_ignored) {

                val range = line_range.restrict(snapshot.convert(command.range + command_start))

                val p = text_area.offsetToXY(range.start)

                val q = text_area.offsetToXY(range.stop)

                if (p != null && q != null) {

                  gfx.setColor(Document_View.choose_color(snapshot, command))

                  gfx.fillRect(p.x, y, q.x - p.x, line_height)

                }

              }

            }

            y += line_height

          }

        }

        finally { gfx.setColor(saved_color) }

      }

    }

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

    {

      Isabelle.swing_buffer_lock(model.buffer) {

        val snapshot = model.snapshot()

        val offset = text_area.xyToOffset(x, y)

        val markup =

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

            case Text.Info(range, XML.Elem(Markup(Markup.ML_TYPING, _), body)) =>

              Isabelle.tooltip(Pretty.string_of(List(Pretty.block(body)), margin = 40))

          } { null }

        if (markup.hasNext) markup.next.info else null

      }

    }

  }

  /* caret handling */

  def selected_command(): Option[Command] =

  {

    Swing_Thread.require()

    model.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 getToolTipText(event: MouseEvent): String =

    {

      val line = y_to_line(event.getY())

      if (line >= 0 && line < text_area.getLineCount) "<html><b>TODO:</b><br>Tooltip</html>"

      else ""

    }

    override def paintComponent(gfx: Graphics)

    {

      super.paintComponent(gfx)

      Swing_Thread.assert()

      val buffer = model.buffer

      Isabelle.buffer_lock(buffer) {

        val snapshot = model.snapshot()

        val saved_color = gfx.getColor  // FIXME needed!?

        try {

          for ((command, start) <- snapshot.node.command_starts if !command.is_ignored) {

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

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

            val y = line_to_y(line1)

            val height = HEIGHT * (line2 - line1)

            gfx.setColor(Document_View.choose_color(snapshot, command))

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

          }

        }

        finally { gfx.setColor(saved_color) }

      }

    }

    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

  }

  /* activation */

  private def activate()

  {

    text_area.getPainter.

      addExtension(TextAreaPainter.LINE_BACKGROUND_LAYER + 1, text_area_extension)

    text_area.addCaretListener(caret_listener)

    text_area.addLeftOfScrollBar(overview)

    session.commands_changed += commands_changed_actor

  }

  private def deactivate()

  {

    session.commands_changed -= commands_changed_actor

    text_area.removeLeftOfScrollBar(overview)

    text_area.removeCaretListener(caret_listener)

    text_area.getPainter.removeExtension(text_area_extension)

  }

}