/*
 *                    BioJava development code
 *
 * This code may be freely distributed and modified under the
 * terms of the GNU Lesser General Public Licence.  This should
 * be distributed with the code.  If you do not have a copy,
 * see:
 *
 *      http://www.gnu.org/copyleft/lesser.html
 *
 * Copyright for this code is held jointly by the individual
 * authors.  These should be listed in @author doc comments.
 *
 * For more information on the BioJava project and its aims,
 * or to join the biojava-l mailing list, visit the home page
 * at:
 *
 *      http://www.biojava.org/
 *
 */

package org.biojava.bio.gui.sequence;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.Paint;
import java.awt.Rectangle;
import java.awt.Shape;
import java.awt.font.FontRenderContext;
import java.awt.font.TextLayout;
import java.awt.geom.AffineTransform;
import java.awt.geom.Rectangle2D;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

import org.biojava.utils.AbstractChangeable;
import org.biojava.utils.AssertionFailure;
import org.biojava.utils.ChangeEvent;
import org.biojava.utils.ChangeForwarder;
import org.biojava.utils.ChangeSupport;
import org.biojava.utils.ChangeType;
import org.biojava.utils.ChangeVetoException;
import org.biojava.utils.Changeable;


/**
 * Renderer which draws a track of sequence with a textual label.
 *
 * <p>
 * <strong>Experimental:</strong> This should probably delegate the label-drawing to a little
 * LabelRenderer interface, and have the option of rendering trailing as well as leading labels.
 * </p>
 *
 * @author Kalle Naslund
 * @author Thomas Down
 * @author Matthew Pocock
 * @author Andreas Prlic
 * @since 1.3
 */


public class LabelledSequenceRenderer extends AbstractChangeable implements SequenceRenderer {
    // keeps track if this label renderer is selected or not
    boolean             selected        =   true;
    // the sequence we are rendering the label for
    SequenceRenderer    seqRend         =   null;
    // the area the label occupies
    double              width           =   200;
    double              depth           =   100;
    // list that contains the text our lable should display
    List                labels          =   new ArrayList();
    // the area that mouse clicks should be caught on, set it to no area in the beginning
    Rectangle           mouseClickArea  =   new Rectangle( 0, 0, -1, -1 );
    // the render forwarder needed to handle ChangeEvents from the encapsuled renderer correctly
    private transient   ChangeForwarder rendererForwarder = null;
    // the ChangeEvents this renderer can emit, due to certain things
    public static final ChangeType RENDERER  = new ChangeType(  "The SequenceRenderer has been added or removed",
                                                                LabelledSequenceRenderer.class,
                                                                "RENDERER",
                                                                SequenceRenderContext.LAYOUT );

    public static final ChangeType VALUES   = new ChangeType(   "The label value has changed",
                                                                LabelledSequenceRenderer.class,
                                                                "VALUES",
                                                                SequenceRenderContext.REPAINT );


    Color fillColor = Color.white ;
    Color textColor = Color.black ;
    
    protected ChangeSupport generateChangeSupport() {
        ChangeSupport cs    =   super.generateChangeSupport();
        rendererForwarder = new SequenceRenderer.RendererForwarder( this, cs );
        if( ( seqRend != null ) && ( seqRend instanceof Changeable ) ) {
            Changeable c = ( Changeable ) seqRend;
            c.addChangeListener( rendererForwarder, SequenceRenderContext.REPAINT );
            c.addChangeListener( rendererForwarder, SequenceRenderContext.LAYOUT );  // do i need this ?
        }

        return cs;
    }

     /**
      * Creates new LabelledSequenceRenderer with default width and depth;
      */

    public LabelledSequenceRenderer() {
    }

  public LabelledSequenceRenderer(String label, SequenceRenderer renderer) {

    try {
      addLabelString(label);
      setRenderer(renderer);
    } catch (ChangeVetoException e) {
      throw new AssertionFailure("We should not have listeners yet", e);
    }
  }

    /**
     * Creates new LabelledSequenceRenderer with the specified width and depth.
     */
    public LabelledSequenceRenderer( double minWidth, double minDepth ) {
        width   =   minWidth;
        depth   =   minDepth;
    }

    /**
     * Set the child renderer responsible for drawing the contents of this track
     */

    public void setRenderer( SequenceRenderer sR ) throws ChangeVetoException { // should transmit LAYOUT event
        if( hasListeners() ) {
            ChangeEvent     ce  =   new ChangeEvent( this, RENDERER, sR, seqRend );
            ChangeSupport   cs  =   getChangeSupport( RENDERER );

            synchronized( cs ) {
                cs.firePreChangeEvent( ce );

                if( ( seqRend != null ) && ( seqRend instanceof Changeable ) ) {
                    Changeable c = ( Changeable )seqRend;
                    c.removeChangeListener( rendererForwarder );
                }

                seqRend = sR;

                if( seqRend instanceof Changeable ) {
                    Changeable c = ( Changeable )seqRend;
                    c.addChangeListener( rendererForwarder );
                }

                cs.firePostChangeEvent( ce );
            }
        }
        else {
            seqRend = sR;
        }


    }

    /**
     * Add a piece of text to this renderer's label
     */

    public void addLabelString( String text ) throws ChangeVetoException {   // should trigger REPAINT, as currently no layout change can be triggered by more text
        if( hasListeners() ) {                                               // LAYOUT if i later let text affect the size of the renderer etc
            ChangeSupport   cs  =   getChangeSupport( VALUES );
            ChangeEvent     ce  =   new ChangeEvent( this, VALUES, text );

            synchronized( cs ) {
                cs.firePreChangeEvent( ce );
                labels.add( text );
                cs.firePostChangeEvent( ce );
            }

        }
        else {
            labels.add( text );
        }
    }

    /**
     * Remove a piece of text from the label
     */

    public void removeLabelString( String text ) throws ChangeVetoException {
        if( hasListeners() ) {
            ChangeSupport   cs  =   getChangeSupport( VALUES );
            ChangeEvent     ce  =   new ChangeEvent( this, VALUES, null, text );

            synchronized ( cs ) {
                cs.firePreChangeEvent( ce );
                labels.remove( text );
                cs.firePostChangeEvent( ce );
            }
        }
        else {
            labels.remove( text );                          // should handle exceptions i guess ?
        }
    }

    public void toggleSelectionStatus() throws ChangeVetoException {                   // should throw repaint i guess
        boolean     newStatus;

        if( selected ) {
            newStatus = false;
        }
        else {
            newStatus = true;
        }

        if( hasListeners() ) {
            ChangeSupport   cs  =   getChangeSupport( VALUES );
            ChangeEvent     ce  =   new ChangeEvent( this, VALUES );  // i cant just pass the bools here, i need to convert to objects

            synchronized( cs ) {
                cs.firePreChangeEvent( ce );
                selected = newStatus;
                cs.firePostChangeEvent( ce );
            }
        }
        else {
            selected = newStatus;
        }
    }

    // SequenceRenderer interface implemented here
    public double getMinimumLeader( SequenceRenderContext sRC ) {
        return width + seqRend.getMinimumLeader( sRC );
    }


    public double getMinimumTrailer( SequenceRenderContext sRC ) {
        return seqRend.getMinimumTrailer( sRC );
    }


    public double getDepth( SequenceRenderContext sRC ) {
        return Math.max( depth , seqRend.getDepth( sRC ) );
    }


    public SequenceViewerEvent processMouseEvent( org.biojava.bio.gui.sequence.SequenceRenderContext sRC, java.awt.event.MouseEvent mE, java.util.List path ) {

      SequenceViewerEvent sVE;

      path.add( this );
      if( mouseClickArea.contains( mE.getX(), mE.getY() )) {
        sVE = new SequenceViewerEvent( this, this, 1, mE, path );
      } else {
        if (sRC.getDirection() == SequenceRenderContext.VERTICAL) {
          mE.translatePoint(0, -(int)width);
          sVE = seqRend.processMouseEvent( sRC, mE, path );
        } else {
          mE.translatePoint(-(int)width, 0);
          sVE = seqRend.processMouseEvent( sRC, mE, path );
        }
      }

      return sVE;
    }

    
    /** Set the background color of the label area. 
     *  */
    public void setFillColor(Color c){
        fillColor = c;
    }
    /** Get the background color of the label area. 
     * */
    public Color getFillColor(){
        return fillColor;
    }
    
    /** Set the color of the label text 
     * */
    public void setTextColor (Color c) {
        textColor = c;
    }
    
    /** Get the color of the label text 
     * */
    public Color getTextColor() {
        return textColor;
    }
    

    public void paint( Graphics2D g, SequenceRenderContext sRC ) {
        Paint           selectedFill        = fillColor;
        Paint           textCol             = textColor;
        Paint           notSelectedFill     = g.getBackground();

        Shape           originalClip        = g.getClip();
        AffineTransform originalTransform   = g.getTransform();

        Rectangle2D         labelArea       = new Rectangle2D.Double();
        Font                font            = sRC.getFont();
        FontRenderContext   fRC             = g.getFontRenderContext();


        if( sRC.getDirection() == SequenceRenderContext.VERTICAL ) {
            // rotate the drawing
            g.rotate( - java.lang.Math.PI / 2 );
            g.translate( -width, 0 );
            // set the area we should grab mouseclicks in, this could most
            // likely be cached in som way
            mouseClickArea.setRect( 0.0 , -width , depth, width );
        }
        else {
            // set the area that we grab mouseclicks in
            mouseClickArea.setRect( -width, 0.0, width, depth );
        }

        // all below this is the same for vertical or horizontal drawing, as i am
        // just using the built in transformation stuff to get text and stuff
        // at the right possition, as its the simple way of drawing text

        // set cliping zone so we only can draw in our label area
        labelArea.setRect( -width , 0.0, width, depth );
        g.clip( labelArea );

         
        // draw the label area
        if( selected ) {
            g.setPaint( selectedFill );
        } else {
            g.setPaint( notSelectedFill );
        }
        g.fill( labelArea );
        g.setPaint( textCol );

        // draw text
        float   drawPosY    = 3; // initial positions for text placement
        float   drawPosX    = (float) (5 - width);

        // iterate over each string of the label
        for( Iterator labelIterator = labels.iterator() ; labelIterator.hasNext() ; ) {

            // get the current string, and setup the drawign crap for it
            String      currentString   =   ( String )labelIterator.next();
            TextLayout  tLayout         =   new TextLayout( currentString, font, fRC );

            drawPosY += tLayout.getAscent();
            tLayout.draw( g, drawPosX, drawPosY );
            drawPosY += ( tLayout.getDescent() +    tLayout.getLeading()  );
        }

        //g.setTransform( originalTransform );
        // reset the clip and transformation so the next renderer can draw its things

        g.setTransform( originalTransform );
        g.setClip( originalClip );

        // have the renderer render
        seqRend.paint( g, sRC );
    }
}