/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.modeling.ui.diagram.style;

import java.awt.Color;
import java.awt.Font;
import java.awt.geom.AffineTransform;

import org.simantics.databoard.Bindings;
import org.simantics.datatypes.literal.Vec2d;
import org.simantics.db.ReadGraph;
import org.simantics.db.Resource;
import org.simantics.db.exception.DatabaseException;
import org.simantics.db.layer0.variable.Variable;
import org.simantics.diagram.elements.TextNode;
import org.simantics.diagram.profile.StyleBase;
import org.simantics.diagram.synchronization.graph.DiagramGraphUtil;
import org.simantics.g2d.utils.Alignment;
import org.simantics.layer0.Layer0;
import org.simantics.modeling.ModelingResources;
import org.simantics.scenegraph.INode;
import org.simantics.scenegraph.g2d.IG2DNode;
import org.simantics.scenegraph.g2d.nodes.SingleElementNode;
import org.simantics.scenegraph.profile.EvaluationContext;
import org.simantics.scenegraph.profile.common.ProfileVariables;
import org.simantics.scenegraph.utils.NodeUtil;
import org.simantics.utils.datastructures.map.Tuple;


/**
 * @author Tuukka Lehtonen
 */
public class SymbolTerminalNameStyle extends StyleBase<SymbolNameResult> {

    static final Font FONT = Font.decode("Arial 6"); //$NON-NLS-1$

    private static final String NODE_NAME = "terminalName"; //$NON-NLS-1$

    /**
     * Must override the StyleBase implementation because terminals do not
     * depend on runtime variable. They need to be shown regardless of variable
     * existence.
     */
    @Override
    public SymbolNameResult calculateStyle(ReadGraph graph, Resource runtimeDiagram, Resource entry, Resource groupItem) throws DatabaseException {
        return calculateStyle(graph, runtimeDiagram, entry, groupItem, null);
    }

    @Override
    public SymbolNameResult calculateStyle(ReadGraph graph, Resource runtimeDiagram, Resource entry, Resource element, Variable configuration) throws DatabaseException {

        AffineTransform transform = DiagramGraphUtil.getAffineTransform(graph, element);

        Layer0 L0 = Layer0.getInstance(graph);
        ModelingResources MOD = ModelingResources.getInstance(graph);

        Resource binds = DiagramGraphUtil.getPossibleConnectionPointOfTerminal(graph, element);
        if (binds == null)
            return null;

        Resource conn = graph.getPossibleObject(binds, MOD.DiagramConnectionRelationToConnectionRelation);
        String name = graph.getPossibleRelatedValue(conn, L0.HasName, Bindings.STRING);
        if (conn == null || name == null)
            return null;

        return new SymbolNameResult(name, transform);

    }

    private AffineTransform translateAndScaleIfNeeded(AffineTransform tr, Vec2d offset, double scale) {
    	if(!offset.isZero() || scale != 1.0) {
    		tr = new AffineTransform(tr);
    		tr.translate(offset.x, offset.y);
    		tr.scale(scale, scale);
    	}
    	return tr;
    }
    
    private AffineTransform getSymbolTransform(INode node, Vec2d offset, double size) {
    	if(node instanceof SingleElementNode) {
    		SingleElementNode s = (SingleElementNode)node;
    		INode symbol = NodeUtil.findChildByPrefix(s, "composite_image");  //$NON-NLS-1$
        	return translateAndScaleIfNeeded(symbol != null ? ((IG2DNode)symbol).getTransform() : new AffineTransform(), offset, size);
    	}
    	return null;
    }
    
    @Override
    public void applyStyleForNode(EvaluationContext observer, INode _node, SymbolNameResult result) {
    	
        if (result == null) {
            ProfileVariables.denyChild(_node, "", NODE_NAME); //$NON-NLS-1$
            return;
        }

        TextNode node = ProfileVariables.claimChild(_node, "", NODE_NAME, TextNode.class, observer); //$NON-NLS-1$

        node.setZIndex( Integer.MAX_VALUE );
        node.setTransform( getSymbolTransform(_node, new Vec2d(0, -1), 0.08) ); 
        node.setText(result.getName());
        node.setHorizontalAlignment((byte)Alignment.CENTER.ordinal());
        node.setBackgroundColor(Color.WHITE);
        node.setPadding(0.2, 0);
        
    }

    @Override
    protected void cleanupStyleForNode(INode node) {
        ProfileVariables.denyChild(node, "", NODE_NAME); //$NON-NLS-1$
    }

}

/**
 * This is needed to keep the issue decoration up-to-date when its parent
 * element moves.
 */
class SymbolNameResult extends Tuple {
    public SymbolNameResult(String name, AffineTransform transform) {
        super(name, transform);
    }
    public String getName() {
        return (String) getField(0);
    }
}