/**
 * Copyright 2010-2012 Jingjing Li.
 *
 * This file is part of jplot2d.
 *
 * jplot2d is free software: you can redistribute it and/or modify it
 * under the terms of the GNU Lesser General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or any later version.
 *
 * jplot2d 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 General Lesser Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License
 * along with jplot2d. If not, see .
 */
package org.jplot2d.element.impl;

import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics2D;
import java.awt.geom.AffineTransform;
import java.awt.geom.Dimension2D;
import java.awt.geom.Path2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;

import org.jplot2d.element.HAlign;
import org.jplot2d.element.VAlign;
import org.jplot2d.tex.MathElement;
import org.jplot2d.tex.MathLabel;
import org.jplot2d.tex.TeXMathUtils;
import org.jplot2d.util.DoubleDimension2D;
import org.jplot2d.util.SymbolShape;

/**
 * @author Jingjing Li
 * 
 */
public class XYLegendItemImpl extends LegendItemImpl implements XYLegendItemEx {

	private static final double LABEL_SPACE = 8;

	private static final double LINE_LENGTH = 24;

	private float symbolSize = Float.NaN;

	private MathElement textModel;

	private transient MathLabel label;

	public XYLegendItemImpl() {

	}

	public XYGraphEx getParent() {
		return (XYGraphEx) super.getParent();
	}

	public void setLegend(LegendEx legend) {
		Font oldFont = (getLegend() == null) ? null : getLegend().getEffectiveFont();
		super.setLegend(legend);
		if (legend != null && !legend.getEffectiveFont().equals(oldFont)) {
			label = null;
			if (isVisible()) {
				if (getLegend() != null) {
					getLegend().itemSizeChanged(this);
				}
			}
		}
	}

	public void legendEffectiveFontChanged() {
		label = null;
		if (isVisible()) {
			if (getLegend() != null) {
				getLegend().itemSizeChanged(this);
			}
		}
	}

	private MathLabel getLabel() {
		if (label == null && getLegend() != null && getLegend().getEffectiveFont().getSize2D() > 0) {
			label = new MathLabel(textModel, getLegend().getEffectiveFont(), VAlign.MIDDLE, HAlign.LEFT);
		}
		return label;
	}

	public Dimension2D getSize() {
		if (getLabel() == null) {
			return null;
		}
		Rectangle2D labelBounds = getLabel().getBounds();
		double width = labelBounds.getWidth();
		double height = labelBounds.getHeight();
		// System.out.println(height);
		if (height < getEffectiveSymbolSize()) {
			height = getEffectiveSymbolSize();
		}
		return new DoubleDimension2D(LINE_LENGTH + LABEL_SPACE + width, height);
	}

	public String getText() {
		return TeXMathUtils.toString(textModel);
	}

	public void setText(String text) {
		boolean contributable = canContribute();
		textModel = TeXMathUtils.parseText(text);
		label = null;
		if (getLegend() != null) {
			if (canContribute() != contributable) {
				getLegend().itemContribitivityChanged(this);
			} else if (contributable) {
				getLegend().itemSizeChanged(this);
			}
		}
	}

	public boolean canContribute() {
		return textModel != null && textModel != MathElement.EMPTY;
	}

	public float getSymbolSize() {
		return symbolSize;
	}

	public void setSymbolSize(float size) {
		if (symbolSize != size) {
			symbolSize = size;
			symbolSizeChanged();
		}
	}

	public void graphSymbolSizeChanged() {
		if (Float.isNaN(symbolSize)) {
			symbolSizeChanged();
		}
	}

	private void symbolSizeChanged() {
		if (isVisible() && getLegend() != null) {
			getLegend().itemSizeChanged(this);
		}
	}

	private float getEffectiveSymbolSize() {
		if (Float.isNaN(symbolSize)) {
			return getParent().getSymbolSize();
		} else {
			return symbolSize;
		}
	}

	public void draw(Graphics2D g) {
		Point2D loc = getLocation();

		/* draw line and mark */
		XYGraphEx graph = getParent();

		float ax = (float) loc.getX();
		float bx = ax + (float) (LINE_LENGTH);
		float ay = (float) loc.getY();
		float by = ay;

		Color sc = graph.getEffectiveSymbolColor();
		if (graph.isLineVisible()) {
			g.setColor(graph.getEffectiveColor());
			g.setStroke(graph.getLineStroke());
			Path2D.Float gp = new Path2D.Float();
			gp.moveTo(ax, ay);
			gp.lineTo(bx, by);
			g.draw(gp);
			if (graph.isSymbolVisible()) {
				drawSymbol(g, ax, ay, sc);
				drawSymbol(g, bx, by, sc);
			}
		} else if (graph.isSymbolVisible()) {
			drawSymbol(g, bx, by, sc);
		}

		/* draw label */
		drawLabel(g);
	}

	private void drawSymbol(Graphics2D g, float x, float y, Color color) {
		XYGraphEx graph = getParent();

		// use half of line stroke to draw marks
		float lw = graph.getLineStroke().getLineWidth() / 2;
		g.setStroke(new BasicStroke(lw, BasicStroke.CAP_BUTT, BasicStroke.JOIN_MITER));
		g.setColor(color);

		float actSymbolSize = getEffectiveSymbolSize();
		AffineTransform maf = AffineTransform.getTranslateInstance(x, y);
		maf.scale(actSymbolSize, actSymbolSize);

		SymbolShape ss = graph.getSymbolShape();
		ss.draw(g, maf);
	}

	private void drawLabel(Graphics2D g) {
		AffineTransform oldTransform = g.getTransform();

		g.translate(getLocation().getX() + LINE_LENGTH + LABEL_SPACE, getLocation().getY());
		g.scale(1.0, -1.0);
		g.setColor(Color.BLACK);
		getLabel().draw(g);

		g.setTransform(oldTransform);
	}

	@Override
	public void copyFrom(ElementEx src) {
		super.copyFrom(src);

		XYLegendItemImpl xyli = (XYLegendItemImpl) src;
		textModel = xyli.textModel;
	}

}