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

     Author:     Makarius

 Misc library functions for jEdit.

 */

 package isabelle.jedit

 import isabelle._

 import java.awt.{Component, Container, GraphicsEnvironment, Point, Rectangle, Dimension}

 import java.awt.event.{InputEvent, KeyEvent, KeyListener}

 import javax.swing.{Icon, ImageIcon, JWindow, SwingUtilities}

 import scala.annotation.tailrec

 import org.gjt.sp.jedit.{jEdit, Buffer, View, GUIUtilities, Debug}

 import org.gjt.sp.jedit.gui.KeyEventWorkaround

 import org.gjt.sp.jedit.buffer.JEditBuffer

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

 object JEdit_Lib

 {

   /* location within multi-screen environment */

   final case class Screen_Location(point: Point, bounds: Rectangle)

   {

     def relative(parent: Component, size: Dimension): Point =

     {

       val w = size.width

       val h = size.height

       val x0 = parent.getLocationOnScreen.x

       val y0 = parent.getLocationOnScreen.y

       val x1 = x0 + parent.getWidth - w

       val y1 = y0 + parent.getHeight - h

       val x2 = point.x min (bounds.x + bounds.width - w)

       val y2 = point.y min (bounds.y + bounds.height - h)

       val location = new Point((x2 min x1) max x0, (y2 min y1) max y0)

       SwingUtilities.convertPointFromScreen(location, parent)

       location

     }

   }

   def screen_location(component: Component, point: Point): Screen_Location =

   {

     val screen_point = new Point(point.x, point.y)

     SwingUtilities.convertPointToScreen(screen_point, component)

     val ge = GraphicsEnvironment.getLocalGraphicsEnvironment

     val screen_bounds =

       (for {

         device <- ge.getScreenDevices.iterator

         config <- device.getConfigurations.iterator

         bounds = config.getBounds

       } yield bounds).find(_.contains(screen_point)) getOrElse ge.getMaximumWindowBounds

     Screen_Location(screen_point, screen_bounds)

   }

   /* window geometry measurement */

   private lazy val dummy_window = new JWindow

   final case class Window_Geometry(width: Int, height: Int, inner_width: Int, inner_height: Int)

   {

     def deco_width: Int = width - inner_width

     def deco_height: Int = height - inner_height

   }

   def window_geometry(outer: Container, inner: Component): Window_Geometry =

   {

     Swing_Thread.require()

     val old_content = dummy_window.getContentPane

     dummy_window.setContentPane(outer)

     dummy_window.pack

     dummy_window.revalidate

     val geometry =

       Window_Geometry(

         dummy_window.getWidth, dummy_window.getHeight, inner.getWidth, inner.getHeight)

     dummy_window.setContentPane(old_content)

     geometry

   }

   /* buffers */

   def swing_buffer_lock[A](buffer: JEditBuffer)(body: => A): A =

     Swing_Thread.now { buffer_lock(buffer) { body } }

   def buffer_text(buffer: JEditBuffer): String =

     buffer_lock(buffer) { buffer.getText(0, buffer.getLength) }

   def buffer_mode(buffer: JEditBuffer): String =

   {

     val mode = buffer.getMode

     if (mode == null) ""

     else {

       val name = mode.getName

       if (name == null) "" else name

     }

   }

   def buffer_name(buffer: Buffer): String = buffer.getSymlinkPath

   /* main jEdit components */

   def jedit_buffers(): Iterator[Buffer] = jEdit.getBuffers().iterator

   def jedit_buffer(name: String): Option[Buffer] =

     jedit_buffers().find(buffer => buffer_name(buffer) == name)

   def jedit_views(): Iterator[View] = jEdit.getViews().iterator

   def jedit_text_areas(view: View): Iterator[JEditTextArea] =

     view.getEditPanes().iterator.map(_.getTextArea)

   def jedit_text_areas(): Iterator[JEditTextArea] =

     jedit_views().flatMap(jedit_text_areas(_))

   def jedit_text_areas(buffer: JEditBuffer): Iterator[JEditTextArea] =

     jedit_text_areas().filter(_.getBuffer == buffer)

   def buffer_lock[A](buffer: JEditBuffer)(body: => A): A =

   {

     try { buffer.readLock(); body }

     finally { buffer.readUnlock() }

   }

   def buffer_edit[A](buffer: JEditBuffer)(body: => A): A =

   {

     try { buffer.beginCompoundEdit(); body }

     finally { buffer.endCompoundEdit() }

   }

   /* get text */

   def try_get_text(buffer: JEditBuffer, range: Text.Range): Option[String] =

     try { Some(buffer.getText(range.start, range.length)) }

     catch { case _: ArrayIndexOutOfBoundsException => None }

   def try_get_text(text: String, range: Text.Range): Option[String] =

     try { Some(text.substring(range.start, range.stop)) }

     catch { case _: IndexOutOfBoundsException => None }

   /* point range */

   def point_range(buffer: JEditBuffer, offset: Text.Offset): Text.Range =

     buffer_lock(buffer) {

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

       try {

         val c = text(offset)

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

           Text.Range(offset, offset + 2)

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

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

         else

           Text.Range(offset, offset + 1)

       }

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

     }

   /* text ranges */

   def buffer_range(buffer: JEditBuffer): Text.Range =

     Text.Range(0, buffer.getLength)

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

   {

     val buffer = text_area.getBuffer

     val n = text_area.getVisibleLines

     if (n > 0) {

       val start = text_area.getScreenLineStartOffset(0)

       val raw_end = text_area.getScreenLineEndOffset(n - 1)

       val end = if (raw_end >= 0) raw_end min buffer.getLength else buffer.getLength

       Some(Text.Range(start, end))

     }

     else None

   }

   def invalidate_range(text_area: TextArea, range: Text.Range)

   {

     val buffer = text_area.getBuffer

     buffer_range(buffer).try_restrict(range) match {

       case Some(range1) if !range1.is_singularity =>

         text_area.invalidateLineRange(

           buffer.getLineOfOffset(range1.start),

           buffer.getLineOfOffset(range1.stop))

       case _ =>

     }

   }

   /* graphics range */

   case class Gfx_Range(val x: Int, val y: Int, val length: Int)

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

   // NB: last line lacks \n

   def gfx_range(text_area: TextArea, range: Text.Range): Option[Gfx_Range] =

   {

     val metric = pretty_metric(text_area.getPainter)

     val char_width = (metric.unit * metric.average).round.toInt

     val buffer = text_area.getBuffer

     val end = buffer.getLength

     val stop = range.stop

     val (p, q, r) =

       try {

         val p = text_area.offsetToXY(range.start)

         val (q, r) =

           if (try_get_text(buffer, Text.Range(stop - 1, stop)) == Some("\n"))

             (text_area.offsetToXY(stop - 1), char_width)

           else if (stop >= end)

             (text_area.offsetToXY(end), char_width * (stop - end))

           else (text_area.offsetToXY(stop), 0)

         (p, q, r)

       }

       catch { case _: ArrayIndexOutOfBoundsException => (null, null, 0) }

     if (p != null && q != null && p.x < q.x + r && p.y == q.y)

       Some(Gfx_Range(p.x, p.y, q.x + r - p.x))

     else None

   }

   /* pixel range */

   def pixel_range(text_area: TextArea, x: Int, y: Int): Option[Text.Range] =

   {

     // coordinates wrt. inner painter component

     val painter = text_area.getPainter

     if (0 <= x && x < painter.getWidth && 0 <= y && y < painter.getHeight) {

       val offset = text_area.xyToOffset(x, y, false)

       if (offset >= 0) {

         val range = point_range(text_area.getBuffer, offset)

         gfx_range(text_area, range) match {

           case Some(g) if (g.x <= x && x < g.x + g.length) => Some(range)

           case _ => None

         }

       }

       else None

     }

     else None

   }

   /* pretty text metric */

   abstract class Pretty_Metric extends Pretty.Metric

   {

     def average: Double

   }

   def pretty_metric(painter: TextAreaPainter): Pretty_Metric =

     new Pretty_Metric {

       def string_width(s: String): Double =

         painter.getFont.getStringBounds(s, painter.getFontRenderContext).getWidth

       val unit = string_width(Pretty.space)

       val average = string_width("mix") / (3 * unit)

       def apply(s: String): Double = if (s == "\n") 1.0 else string_width(s) / unit

     }

   /* icons */

   def load_icon(name: String): Icon =

   {

     val name1 =

       if (name.startsWith("idea-icons/")) {

         val file =

           Isabelle_System.platform_file_url(Path.explode("$JEDIT_HOME/dist/jars/idea-icons.jar"))

         "jar:" + file + "!/" + name

       }

       else name

     val icon = GUIUtilities.loadIcon(name1)

     if (icon.getIconWidth < 0 || icon.getIconHeight < 0) error("Bad icon: " + name)

     else icon

   }

   def load_image_icon(name: String): ImageIcon =

     load_icon(name) match {

       case icon: ImageIcon => icon

       case _ => error("Bad image icon: " + name)

     }

   /* key event handling */

   def request_focus_view

   {

     val view = jEdit.getActiveView()

     if (view != null) {

       val text_area = view.getTextArea

       if (text_area != null) text_area.requestFocus

     }

   }

   def propagate_key(view: View, evt: KeyEvent)

   {

     if (view != null && !evt.isConsumed)

       view.getInputHandler().processKeyEvent(evt, View.ACTION_BAR, false)

   }

   def key_listener(

     key_typed: KeyEvent => Unit = _ => (),

     key_pressed: KeyEvent => Unit = _ => (),

     key_released: KeyEvent => Unit = _ => ()): KeyListener =

   {

     def process_key_event(evt0: KeyEvent, handle: KeyEvent => Unit)

     {

       val evt = KeyEventWorkaround.processKeyEvent(evt0)

       if (evt != null) handle(evt)

     }

     new KeyListener

     {

       def keyTyped(evt: KeyEvent) { process_key_event(evt, key_typed) }

       def keyPressed(evt: KeyEvent) { process_key_event(evt, key_pressed) }

       def keyReleased(evt: KeyEvent) { process_key_event(evt, key_released) }

     }

   }

   def special_key(evt: KeyEvent): Boolean =

   {

     // cf. 5.1.0/jEdit/org/gjt/sp/jedit/gui/KeyEventWorkaround.java

     val mod = evt.getModifiers

     (mod & InputEvent.CTRL_MASK) != 0 && (mod & InputEvent.ALT_MASK) == 0 ||

     (mod & InputEvent.CTRL_MASK) == 0 && (mod & InputEvent.ALT_MASK) != 0 &&

       !Debug.ALT_KEY_PRESSED_DISABLED ||

     (mod & InputEvent.META_MASK) != 0

   }

 }