/*
 *  RapidMiner
 *
 *  Copyright (C) 2001-2014 by RapidMiner and the contributors
 *
 *  Complete list of developers available at our web site:
 *
 *       http://rapidminer.com
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU Affero General Public License as published by
 *  the Free Software Foundation, either version 3 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU Affero General Public License for more details.
 *
 *  You should have received a copy of the GNU Affero General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/.
 */
package com.rapidminer.gui.graphs;

import java.awt.Component;
import java.awt.Dimension;
import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;

import edu.uci.ics.jung.algorithms.layout.Layout;
import edu.uci.ics.jung.graph.Graph;
import edu.uci.ics.jung.graph.util.Context;
import edu.uci.ics.jung.graph.util.Pair;
import edu.uci.ics.jung.visualization.Layer;
import edu.uci.ics.jung.visualization.RenderContext;
import edu.uci.ics.jung.visualization.renderers.EdgeLabelRenderer;
import edu.uci.ics.jung.visualization.renderers.Renderer;
import edu.uci.ics.jung.visualization.transform.shape.GraphicsDecorator;

/**
 * This code is the basic edge label renderer from Jung (unfortunately there was no
 * authot given in the original source) but it was changed so that the labels are always painted
 * in the center location of the edge.
 *
 * @author Ingo Mierswa
 */
public class TreeModelEdgeLabelRenderer<V, E> implements Renderer.EdgeLabel<V, E> {

	public Component prepareRenderer(RenderContext<V, E> rc, EdgeLabelRenderer graphLabelRenderer, Object value, boolean isSelected, E edge) {
		return rc.getEdgeLabelRenderer().<E> getEdgeLabelRendererComponent(rc.getScreenDevice(), value, rc.getEdgeFontTransformer().transform(edge), isSelected, edge);
	}

	public void labelEdge(RenderContext<V, E> rc, Layout<V, E> layout, E e, String label) {
		if (label == null || label.length() == 0)
			return;

		Graph<V, E> graph = layout.getGraph();
		// don't draw edge if either incident vertex is not drawn
		Pair<V> endpoints = graph.getEndpoints(e);
		V v1 = endpoints.getFirst();
		V v2 = endpoints.getSecond();
		if (!rc.getVertexIncludePredicate().evaluate(Context.<Graph<V, E>, V> getInstance(graph, v1)) || !rc.getVertexIncludePredicate().evaluate(Context.<Graph<V, E>, V> getInstance(graph, v2)))
			return;

		Point2D p1 = layout.transform(v1);
		Point2D p2 = layout.transform(v2);
		p1 = rc.getMultiLayerTransformer().transform(Layer.LAYOUT, p1);
		p2 = rc.getMultiLayerTransformer().transform(Layer.LAYOUT, p2);
		float x1 = (float) p1.getX();
		float y1 = (float) p1.getY();
		float x2 = (float) p2.getX();
		float y2 = (float) p2.getY();

		GraphicsDecorator g = rc.getGraphicsContext();
		float distX = x2 - x1;
		float distY = y2 - y1;
		double totalLength = Math.sqrt(distX * distX + distY * distY);

		double closeness = rc.getEdgeLabelClosenessTransformer().transform(Context.<Graph<V, E>, E> getInstance(graph, e)).doubleValue();
		
		int posX = (int) (x1 + (closeness) * distX);
		int posY = (int) (y1 + (closeness) * distY);

		int xDisplacement = 0;
		int yDisplacement = 0;
		
		/* BUG 1: change X and Y in distXXX
		xDisplacement = (int) (rc.getLabelOffset() * (distY / totalLength));
		yDisplacement = (int) (rc.getLabelOffset() * (-distX / totalLength));
		*/
		
		xDisplacement = (int) (rc.getLabelOffset() * (distX / totalLength));
		yDisplacement = (int) (rc.getLabelOffset() * (-distY / totalLength));

		
		// BUG 2
		/*
		Component component = prepareRenderer(rc, rc.getEdgeLabelRenderer(), label, rc.getPickedEdgeState().isPicked(e), e);
		Dimension d = component.getPreferredSize();
		Shape edgeShape = rc.getEdgeShapeTransformer().transform(Context.<Graph<V, E>, E> getInstance(graph, e));
		double parallelOffset = 1;

		parallelOffset -= rc.getParallelEdgeIndexFunction().getIndex(graph, e);

		if (edgeShape instanceof Ellipse2D) {
			parallelOffset += edgeShape.getBounds().getHeight();
			parallelOffset = -parallelOffset;
		}

		parallelOffset *= d.height;
		*/
				
		AffineTransform old = g.getTransform();
		AffineTransform xform = new AffineTransform(old);
		xform.translate(posX + xDisplacement, posY + yDisplacement);

		// BUG 3
		/*
        double dx = x2 - x1;
		double dy = y2 - y1;
		if (rc.getEdgeLabelRenderer().isRotateEdgeLabels()) {
			double theta = Math.atan2(dy, dx);
			if (dx < 0) {
				theta += Math.PI;
			}
			xform.rotate(theta);
		}
		if (dx < 0) {
			parallelOffset = -parallelOffset;
		}
		*/

		double parallelOffset = 0.0d;
		Component component = prepareRenderer(rc, rc.getEdgeLabelRenderer(), label, rc.getPickedEdgeState().isPicked(e), e);
		Dimension d = component.getPreferredSize();
		xform.translate(-d.width / 2.0d, -(d.height / 2.0d - parallelOffset));
		g.setTransform(xform);
		g.draw(component, rc.getRendererPane(), 0, 0, d.width, d.height, true);
		g.setTransform(old);
	}
}