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

     Author:     Makarius

 Outer syntax token markup.

 */

 package isabelle.jedit

 import isabelle._

 import java.awt.{Font, Color}

 import java.awt.font.{TextAttribute, TransformAttribute, FontRenderContext, LineMetrics}

 import java.awt.geom.AffineTransform

 import org.gjt.sp.util.SyntaxUtilities

 import org.gjt.sp.jedit.Mode

 import org.gjt.sp.jedit.syntax.{Token => JEditToken, TokenMarker, TokenHandler,

   ParserRuleSet, ModeProvider, XModeHandler, SyntaxStyle}

 import javax.swing.text.Segment

 object Token_Markup

 {

   /* font operations */

   private def font_metrics(font: Font): LineMetrics =

     font.getLineMetrics("", new FontRenderContext(null, false, false))

   private def imitate_font(family: String, font: Font): Font =

   {

     val font1 = new Font (family, font.getStyle, font.getSize)

     font1.deriveFont(font_metrics(font).getAscent / font_metrics(font1).getAscent * font.getSize)

   }

   private def transform_font(font: Font, transform: AffineTransform): Font =

   {

     import scala.collection.JavaConversions._

     font.deriveFont(Map(TextAttribute.TRANSFORM -> new TransformAttribute(transform)))

   }

   /* extended syntax styles */

   private val plain_range: Int = JEditToken.ID_COUNT

   private val full_range = 6 * plain_range + 1

   private def check_range(i: Int) { require(0 <= i && i < plain_range) }

   def subscript(i: Byte): Byte = { check_range(i); (i + plain_range).toByte }

   def superscript(i: Byte): Byte = { check_range(i); (i + 2 * plain_range).toByte }

   def bold(i: Byte): Byte = { check_range(i); (i + 3 * plain_range).toByte }

   def user_font(idx: Int, i: Byte): Byte = { check_range(i); (i + (4 + idx) * plain_range).toByte }

   val hidden: Byte = (6 * plain_range).toByte

   private def font_style(style: SyntaxStyle, f: Font => Font): SyntaxStyle =

     new SyntaxStyle(style.getForegroundColor, style.getBackgroundColor, f(style.getFont))

   private def script_style(style: SyntaxStyle, i: Int): SyntaxStyle =

   {

     font_style(style, font0 =>

       {

         import scala.collection.JavaConversions._

         val font1 = font0.deriveFont(Map(TextAttribute.SUPERSCRIPT -> new java.lang.Integer(i)))

         def shift(y: Float): Font =

           transform_font(font1, AffineTransform.getTranslateInstance(0.0, y.toDouble))

         val m0 = font_metrics(font0)

         val m1 = font_metrics(font1)

         val a = m1.getAscent - m0.getAscent

         val b = (m1.getDescent + m1.getLeading) - (m0.getDescent + m0.getLeading)

         if (a > 0.0f) shift(a)

         else if (b > 0.0f) shift(- b)

         else font1

       })

   }

   private def bold_style(style: SyntaxStyle): SyntaxStyle =

     font_style(style, _.deriveFont(Font.BOLD))

   class Style_Extender extends SyntaxUtilities.StyleExtender

   {

     if (Symbol.font_names.length > 2)

       error("Too many user symbol fonts (max 2 permitted): " + Symbol.font_names.mkString(", "))

     override def extendStyles(styles: Array[SyntaxStyle]): Array[SyntaxStyle] =

     {

       val new_styles = new Array[SyntaxStyle](full_range)

       for (i <- 0 until plain_range) {

         val style = styles(i)

         new_styles(i) = style

         new_styles(subscript(i.toByte)) = script_style(style, -1)

         new_styles(superscript(i.toByte)) = script_style(style, 1)

         new_styles(bold(i.toByte)) = bold_style(style)

         for ((family, idx) <- Symbol.font_index)

           new_styles(user_font(idx, i.toByte)) = font_style(style, imitate_font(family, _))

       }

       new_styles(hidden) =

         new SyntaxStyle(Color.white, null,

           { val font = styles(0).getFont

             transform_font(new Font(font.getFamily, 0, 1),

               AffineTransform.getScaleInstance(1.0, font.getSize.toDouble)) })

       new_styles

     }

   }

   def extended_styles(text: CharSequence): Map[Text.Offset, Byte => Byte] =

   {

     // FIXME Symbol.is_bsub_decoded etc.

     def ctrl_style(sym: String): Option[Byte => Byte] =

       if (Symbol.is_subscript_decoded(sym)) Some(subscript(_))

       else if (Symbol.is_superscript_decoded(sym)) Some(superscript(_))

       else if (Symbol.is_bold_decoded(sym)) Some(bold(_))

       else None

     var result = Map[Text.Offset, Byte => Byte]()

     def mark(start: Text.Offset, stop: Text.Offset, style: Byte => Byte)

     {

       for (i <- start until stop) result += (i -> style)

     }

     var offset = 0

     var ctrl = ""

     for (sym <- Symbol.iterator(text)) {

       if (ctrl_style(sym).isDefined) ctrl = sym

       else if (ctrl != "") {

         if (Symbol.is_controllable(sym) && sym != "\"" && !Symbol.fonts.isDefinedAt(sym)) {

           mark(offset - ctrl.length, offset, _ => hidden)

           mark(offset, offset + sym.length, ctrl_style(ctrl).get)

         }

         ctrl = ""

       }

       Symbol.lookup_font(sym) match {

         case Some(idx) => mark(offset, offset + sym.length, user_font(idx, _))

         case _ =>

       }

       offset += sym.length

     }

     result

   }

   /* token marker */

   private val isabelle_rules = new ParserRuleSet("isabelle", "MAIN")

   private class Line_Context(val context: Scan.Context)

     extends TokenMarker.LineContext(isabelle_rules, null)

   {

     override def hashCode: Int = context.hashCode

     override def equals(that: Any): Boolean =

       that match {

         case other: Line_Context => context == other.context

         case _ => false

       }

   }

   class Marker extends TokenMarker

   {

     override def markTokens(context: TokenMarker.LineContext,

         handler: TokenHandler, line: Segment): TokenMarker.LineContext =

     {

       val context1 =

         if (Isabelle.session.is_ready) {

           val syntax = Isabelle.session.current_syntax()

           val ctxt =

             context match {

               case c: Line_Context => c.context

               case _ => Scan.Finished

             }

           val (tokens, ctxt1) = syntax.scan_context(line, ctxt)

           val context1 = new Line_Context(ctxt1)

           val extended = extended_styles(line)

           var offset = 0

           for (token <- tokens) {

             val style = Isabelle_Markup.token_markup(syntax, token)

             val length = token.source.length

             val end_offset = offset + length

             if ((offset until end_offset) exists extended.isDefinedAt) {

               for (i <- offset until end_offset) {

                 val style1 =

                   extended.get(i) match {

                     case None => style

                     case Some(ext) => ext(style)

                   }

                 handler.handleToken(line, style1, i, 1, context1)

               }

             }

             else handler.handleToken(line, style, offset, length, context1)

             offset += length

           }

           handler.handleToken(line, JEditToken.END, line.count, 0, context1)

           context1

         }

         else {

           val context1 = new Line_Context(Scan.Finished)

           handler.handleToken(line, JEditToken.NULL, 0, line.count, context1)

           handler.handleToken(line, JEditToken.END, line.count, 0, context1)

           context1

         }

       val context2 = context1.intern

       handler.setLineContext(context2)

       context2

     }

   }

   /* mode provider */

   class Mode_Provider(orig_provider: ModeProvider) extends ModeProvider

   {

     for (mode <- orig_provider.getModes) addMode(mode)

     val isabelle_token_marker = new Token_Markup.Marker

     override def loadMode(mode: Mode, xmh: XModeHandler)

     {

       super.loadMode(mode, xmh)

       if (mode.getName == "isabelle")

         mode.setTokenMarker(isabelle_token_marker)

     }

   }

 }