/*******************************************************************************
 * 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.g2d.utils;

import java.awt.Shape;
import java.awt.geom.CubicCurve2D;
import java.awt.geom.Line2D;
import java.awt.geom.Path2D;
import java.awt.geom.PathIterator;
import java.awt.geom.Point2D;
import java.awt.geom.QuadCurve2D;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Iterator;
import java.util.List;

/**
 * Path Utils.
 * <p>
 * A line segment (linear, quadratic or cubic bezier) is described
 * with a double array. The length of the array describes its degree (4,6,8).
 * The first 2 elements define start point and last 2 the end point.
 * Points in the middle are bezier control points.
 * 
 * @See {@link GeometryUtils} for more geometry related utilities
 * @author Toni Kalajainen
 */
public class PathUtils2 {

	/**
	 * Get tangent of an bezier
	 * @param lineSegment bezier of n degrees
	 * @param degree 1..3 
	 * @param t 0..1
	 * @return unit vector
	 */
	public static Point2D getLineTangent(Shape line, double t, Point2D pt)
	{
		double x=0, y=0;
		if (line instanceof Line2D)
		{
			Line2D l = (Line2D) line;
			x = l.getX1() - l.getX2();
			y = l.getY1() - l.getY2();
		} else if (line instanceof QuadCurve2D) {
			QuadCurve2D l = (QuadCurve2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX();
			double p1y = l.getCtrlY();
			double p2x = l.getX2();
			double p2y = l.getY2();			
			x = 2*t*(p0x - 2*p1x + p2x) + 2*(-p0x + p1x);
			y = 2*t*(p0y - 2*p1y + p2y) + 2*(-p0y + p1y);
			
		} else if (line instanceof CubicCurve2D) {
			CubicCurve2D l = (CubicCurve2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX1();
			double p1y = l.getCtrlY1();
			double p2x = l.getCtrlX2();
			double p2y = l.getCtrlY2();
			double p3x = l.getX2();
			double p3y = l.getY2();			
			x = 3*(1-t)*(1-t)*(p1x-p2x) + 3*(p2x-p1x)*2*t*(1-t) + 3*(p3x-p0x)*t*t;
			y = 3*(1-t)*(1-t)*(p1y-p0y) + 3*(p2y-p1y)*2*t*(1-t) + 3*(p3y-p2y)*t*t;
		} else throw new IllegalArgumentException();
		
		return new Point2D.Double(x, y);
	}
	
	/**
	 * 
	 * @param lineSegment
	 * @param t 0..1
	 * @return
	 */
	public static Point2D getLinePos(Shape line, double t, Point2D pt)
	{		
		assert(line!=null);
		double x=0, y=0;
		if (pt==null) pt = new Point2D.Double();
		
		if (line instanceof Line2D) {
			Line2D l = (Line2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getX2();
			double p1y = l.getY2();
			
			x = p0x*(1-t) + t*p1x;
			y = p0y*(1-t) + t*p1y;
		} else 
		if (line instanceof QuadCurve2D) {
			QuadCurve2D l = (QuadCurve2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX();
			double p1y = l.getCtrlY();
			double p2x = l.getX2();
			double p2y = l.getY2();			
			
			double c2x = p0x-2*p1x+p2x;
			double c2y = p0y-2*p1y+p2y;
			
			double c1x = -2*p0x+2*p1x;
			double c1y = -2*p0y+2*p1y;
			
			double c0x = p0x;
			double c0y = p0y;
			
			x = t*t*c2x+t*c1x+c0x;
			y = t*t*c2y+t*c1y+c0y;
		} else if (line instanceof CubicCurve2D) {
			CubicCurve2D l = (CubicCurve2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX1();
			double p1y = l.getCtrlY1();
			double p2x = l.getCtrlX2();
			double p2y = l.getCtrlY2();
			double p3x = l.getX2();
			double p3y = l.getY2();			

			x = (1-t)*(1-t)*(1-t)*p0x + 3*t*(1-t)*(1-t)*p1x + 3*t*t*(1-t)*p2x + t*t*t*p3x;
			y = (1-t)*(1-t)*(1-t)*p0y + 3*t*(1-t)*(1-t)*p1y + 3*t*t*(1-t)*p2y + t*t*t*p3y;
		} else throw new IllegalArgumentException();
		pt.setLocation(x, y);
		
		return pt;
	}
	
	public static double getLineLength(Shape line)
	{
		if (line instanceof Line2D) {
			Line2D l = (Line2D) line;
			double dx = l.getX2() - l.getX1();
			double dy = l.getY2() - l.getY1();
			return Math.sqrt(dx*dx+dy*dy);
		}
		
		// Quick'n'dirty approximation 
		// TODO Replace with accurate value
		double result = 0;
		Point2D prevPos = getLinePos(line, 0.0, null); 
		for (int i=0; i<10; i++)
		{
			double t = (double)(i+1)/10;
			Point2D pos = getLinePos(line, t, null);
			result += pos.distance(prevPos);
			prevPos.setLocation(pos);
		}
		return result;
	}
	
	public static int getLineDegree(Shape line)
	{
		if (line instanceof Line2D) return 1;
		if (line instanceof QuadCurve2D) return 2;
		if (line instanceof CubicCurve2D) return 3;
		throw new IllegalArgumentException(line+" is not a shape");
	}
	
	
	public static double[] toArray(Shape line)
	{
		if (line instanceof Line2D) {
			Line2D l = (Line2D) line;
			return new double[] {l.getX1(), l.getY1(), l.getX2(), l.getY2()};
		}
		if (line instanceof QuadCurve2D) {
			QuadCurve2D l = (QuadCurve2D) line;
			return new double[] {l.getX1(), l.getY1(), l.getCtrlX(), l.getCtrlY(), l.getX2(), l.getY2()};
		}
		if (line instanceof CubicCurve2D) {
			CubicCurve2D l = (CubicCurve2D) line;
			return new double[] {l.getX1(), l.getY1(), l.getCtrlX1(), l.getCtrlY1(), l.getCtrlX2(), l.getCtrlY2(), l.getX2(), l.getY2()};			
		}
		throw new IllegalArgumentException(line+" is not a shape");		
	}
	
	public static Shape toShape(double dada[])
	{
		if (dada.length==4) 
			return new Line2D.Double(dada[0], dada[1], dada[2], dada[3]);
		if (dada.length==6) 
			return new QuadCurve2D.Double(dada[0], dada[1], dada[2], dada[3], dada[4], dada[5]);
		if (dada.length==8) 
			return new CubicCurve2D.Double(dada[0], dada[1], dada[2], dada[3], dada[4], dada[5], dada[6], dada[7]);
		throw new IllegalArgumentException();
	}

	public static void interpolatePaths(List<Shape> l1, List<Shape> l2, double t, Collection<Shape> result)
	{
		if (l1.size()>l2.size()) {
			List<Shape> l_ = l1;
			l1 = l2;
			l2 = l_;
			t = 1-t;
		}
		
		int div = l2.size() / l1.size();
		int mod = l2.size() % l1.size();
		
		int rightIndex = 0;
		for (int i=0; i<l1.size(); i++) {
			int rightCounterParts = i<l1.size()-1 ? (i<mod?div+1:div) : div; 
			int leftIndex = i;
			Shape leftShape = l1.get(leftIndex); 
			for (int j=0; j<rightCounterParts; j++)
			{
				Shape rightShape = l2.get(rightIndex++);
				double inv = 1/(double)rightCounterParts;
				double t0  = j*inv;
				double t1  = (j+1)*inv;
				Shape leftShapePart  = subdiv(leftShape, t0, t1);				
				Shape intpShape = interpolateLine(leftShapePart, rightShape, t);
				result.add( intpShape );
			}
		}
	}
	
	/**
	 * Interpolate two paths
	 * @param path1
	 * @param path2
	 * @param t phase 0..1, 0==path1, 1==path2
	 * @return
	 */
	public static Path2D interpolatePaths(PathIterator path1, PathIterator path2, double t)
	{
		ArrayList<Shape> l1 = new ArrayList<Shape>();
		ArrayList<Shape> l2 = new ArrayList<Shape>(); 
		toShapes(path1, l1);
		toShapes(path2, l2);
		ArrayList<Shape> result = new ArrayList<Shape>();
		interpolatePaths(l1, l2, t, result);
		Path2D p = new Path2D.Double();
		appedToPath(p, result);
		return p;
	}

	public static Path2D interpolatePaths(Path2D path1, Path2D path2, double t)
	{
		return interpolatePaths(path1.getPathIterator(null), path2.getPathIterator(null), t);
	}
	
	public static Shape interpolateLine(Shape l1, Shape l2, double t)
	{
		assert(t>=0 && t<=1);
		if (t==0) return l1;
		if (t==1) return l2;
		
		double[] a1 = toArray(l1);
		double[] a2 = toArray(l2);
		double[] res = PathUtils.interpolateLineSegment(a1, a2, t);
		return toShape(res);
	}
	
	public static void toShapes(PathIterator pi, Collection<Shape> result)
	{
		Iterator<Shape> i = toShapeIterator(pi);
		while (i.hasNext()) {
			Shape segment = i.next();
			result.add(segment);
		}
	}
	
	/**
	 * Returns an iterator that splits path into line shapes
	 * @param pi path iterator
	 * @return line segment iterator
	 */
	public static Iterator<Shape> toShapeIterator(final PathIterator pi)
	{
		return new PathIteratorToShapeIterator(pi);
	}
	
	private static class PathIteratorToShapeIterator implements Iterator<Shape>
	{
		final PathIterator pi;
		double	lineTo[] = new double[6];
		double	startPos[] = new double[2];
		double	from[] = new double[2];
		int		degree = 0;
		PathIteratorToShapeIterator(PathIterator pi) {
			this.pi = pi;
			while(!pi.isDone()) {
				int type = pi.currentSegment(lineTo);
				pi.next();
				if (type == PathIterator.SEG_MOVETO) {
					startPos[0] = from[0] = lineTo[0];
					startPos[1] = from[1] = lineTo[1];
				}
				if (type == PathIterator.SEG_CLOSE) {
					type = PathIterator.SEG_LINETO;
					lineTo[0] = startPos[0];
					lineTo[1] = startPos[1];
				}
				if (type>=PathIterator.SEG_LINETO && type<=PathIterator.SEG_CUBICTO)
				{
					degree = type;
					// from == xx
					break;
				}
			}
		}		
		@Override
		public boolean hasNext() {
			return degree>0;
		}
		@Override
		public Shape next() {
			if (degree==0) return null;
			Shape res = null;
			if (degree==1) 
				res = new Line2D.Double(from[0], from[1], lineTo[0], lineTo[1]);
			else if (degree==2) 
				res = new QuadCurve2D.Double(from[0], from[1], lineTo[0], lineTo[1], lineTo[2], lineTo[3]);
			else if (degree==3) 
				res = new CubicCurve2D.Double(from[0], from[1], lineTo[0], lineTo[1], lineTo[2], lineTo[3], lineTo[4], lineTo[5]);
			else throw new IllegalArgumentException();
			// traverse path iterator until end or until next segment is known
			degree = 0;
			from[0] = lineTo[0];
			from[1] = lineTo[1];
			while(!pi.isDone()) {
				int type = pi.currentSegment(lineTo);
				pi.next();
				if (type == PathIterator.SEG_MOVETO) {
					startPos[0] = from[0] = lineTo[0];
					startPos[1] = from[1] = lineTo[1];
				}
				if (type == PathIterator.SEG_CLOSE) {
					type = PathIterator.SEG_LINETO;
					lineTo[0] = startPos[0];
					lineTo[1] = startPos[1];
				}
				if (type>=PathIterator.SEG_LINETO && type<=PathIterator.SEG_CUBICTO)
				{
					degree = type;					
					break;
				}
			}
			return res;
		}
		@Override
		public void remove() {
			throw new UnsupportedOperationException();
		}
	}

	
	
	
	public static Shape subdiv_takeLeft(Shape line, double t)
	{
		if (t==1) return line;
		if (line instanceof Line2D) {
			Line2D l = (Line2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getX2();
			double p1y = l.getY2();			
			double p1x_  = p0x*(1-t) + p1x*t;
			double p1y_  = p0y*(1-t) + p1y*t;
			
			return new Line2D.Double( p0x, p0y, p1x_, p1y_ );
		}
		
		if (line instanceof QuadCurve2D) {
			QuadCurve2D l = (QuadCurve2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX();
			double p1y = l.getCtrlY();			
			double p2x = l.getX2();
			double p2y = l.getY2();			
			double p1x_  = p0x*(1-t) + p1x*t;
			double p1y_  = p0y*(1-t) + p1y*t;
		
			double q0x = p0x*(1-t) + p1x*t;
			double q0y = p0y*(1-t) + p1y*t;

			double q1x = p1x*(1-t) + p2x*t;
			double q1y = p1y*(1-t) + p2y*t;
			
			double p2x_ = q0x*(1-t) + q1x*t;
			double p2y_ = q0y*(1-t) + q1y*t;
								
			return new QuadCurve2D.Double( p0x, p0y, p1x_, p1y_, p2x_, p2y_ );			
		}

		if (line instanceof CubicCurve2D) {
			CubicCurve2D l = (CubicCurve2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX1();
			double p1y = l.getCtrlY1();			
			double p2x = l.getCtrlX2();
			double p2y = l.getCtrlY2();			
			double p3x = l.getX2();
			double p3y = l.getY2();			
			double p1x_  = p0x*(1-t) + p1x*t;
			double p1y_  = p0y*(1-t) + p1y*t;
		
			double q0x = p0x*(1-t) + p1x*t;
			double q0y = p0y*(1-t) + p1y*t;

			double q1x = p1x*(1-t) + p2x*t;
			double q1y = p1y*(1-t) + p2y*t;
			
			double p2x_ = q0x*(1-t) + q1x*t;
			double p2y_ = q0y*(1-t) + q1y*t;
			
			double q2x = p2x*(1-t) + p3x*t;
			double q2y = p2y*(1-t) + p3y*t;

			double r0x = q0x*(1-t) + q1x*t;
			double r0y = q0y*(1-t) + q1y*t;
				
			double r1x = q1x*(1-t) + q2x*t;
			double r1y = q1y*(1-t) + q2y*t;
				
			double p3x_  = r0x*(1-t) + r1x*t;
			double p3y_  = r0y*(1-t) + r1y*t;			
			
			return new CubicCurve2D.Double(p0x, p0y, p1x_, p1y_, p2x_, p2y_, p3x_, p3y_);			
		}

		throw new IllegalArgumentException();
	}
	
	public static Shape subdiv_takeRight(Shape line, double t)
	{
		if (t==0) return line;
		if (line instanceof Line2D) {
			Line2D l = (Line2D) line;
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getX2();
			double p1y = l.getY2();			
			double p0x_  = p0x*(1-t) + p1x*t;
			double p0y_  = p0y*(1-t) + p1y*t;
			
			return new Line2D.Double( p0x_, p0y_, p1x, p1y );
		}
		
		if (line instanceof QuadCurve2D) {
			QuadCurve2D l = (QuadCurve2D) line;		
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX();
			double p1y = l.getCtrlY();			
			double p2x = l.getX2();
			double p2y = l.getY2();			

			double q0x = p0x*(1-t) + p1x*t;
			double q0y = p0y*(1-t) + p1y*t;

			double q1x = p1x*(1-t) + p2x*t;
			double q1y = p1y*(1-t) + p2y*t;
			
			double p2x_ = q0x*(1-t) + q1x*t;
			double p2y_ = q0y*(1-t) + q1y*t;
			
			return new QuadCurve2D.Double( p2x_, p2y_, q1x, q1y, p2x, p2y );			
		}		

		
		if (line instanceof CubicCurve2D) {
			CubicCurve2D l = (CubicCurve2D) line;
			
			double p0x = l.getX1();
			double p0y = l.getY1();
			double p1x = l.getCtrlX1();
			double p1y = l.getCtrlY1();			
			double p2x = l.getCtrlX2();
			double p2y = l.getCtrlY2();			
			double p3x = l.getX2();
			double p3y = l.getY2();
			
			double q0x = p0x*(1-t) + p1x*t;
			double q0y = p0y*(1-t) + p1y*t;

			double q1x = p1x*(1-t) + p2x*t;
			double q1y = p1y*(1-t) + p2y*t;
			
			double q2x = p2x*(1-t) + p3x*t;
			double q2y = p2y*(1-t) + p3y*t;

			double r0x = q0x*(1-t) + q1x*t;
			double r0y = q0y*(1-t) + q1y*t;
				
			double r1x = q1x*(1-t) + q2x*t;
			double r1y = q1y*(1-t) + q2y*t;
				
			double p3x_  = r0x*(1-t) + r1x*t;
			double p3y_  = r0y*(1-t) + r1y*t;			
			
			return new CubicCurve2D.Double( p3x_, p3y_, r1x, r1y, q2x, q2y, p3x, p3y );			
		}				
		
		return null;
	}
	


	/**
	 * Crops line segment into a smaller line segment
	 * @param line line segment
	 * @param t0 begin t
	 * @param t1 end t
	 * @return cropped line segment
	 */
	public static Shape subdiv(Shape line, double t0, double t1)
	{
		if (t0==0 && t1==1) return line;
		Shape temp = subdiv_takeLeft(line, t1);
		return subdiv_takeRight(temp, t0/t1);
	}
	
	public static void appedToPath(Path2D p, Shape ... shapes)
	{
		for (Shape s : shapes)
		{
			Point2D cur = p.getCurrentPoint();
			if (s instanceof Line2D) {
				Line2D l = (Line2D) s;
				if (cur.getX()!=l.getX1() || cur.getY()!=l.getY1())
					p.moveTo(l.getX1(), l.getY1());
				p.lineTo(l.getX2(), l.getY2());
			} else if (s instanceof QuadCurve2D) {
				QuadCurve2D l = (QuadCurve2D) s;
				if (cur.getX()!=l.getX1() || cur.getY()!=l.getY1())
					p.moveTo(l.getX1(), l.getY1());
				p.quadTo(l.getCtrlX(), l.getCtrlY(), l.getX2(), l.getY2());
			} else if (s instanceof CubicCurve2D) {
				CubicCurve2D l = (CubicCurve2D) s;
				if (cur.getX()!=l.getX1() || cur.getY()!=l.getY1())
					p.moveTo(l.getX1(), l.getY1());
				p.curveTo(l.getCtrlX1(), l.getCtrlY1(), l.getCtrlX2(), l.getCtrlY2(), l.getX2(), l.getY2());
			} throw new IllegalArgumentException();
		}
	}
	public static void appedToPath(Path2D p, Collection<Shape> shapes)
	{
		for (Shape s : shapes)
		{
			Point2D cur = p.getCurrentPoint();
			if (s instanceof Line2D) {
				Line2D l = (Line2D) s;
				if (cur==null || cur.getX()!=l.getX1() || cur.getY()!=l.getY1())
					p.moveTo(l.getX1(), l.getY1());
				p.lineTo(l.getX2(), l.getY2());
			} else if (s instanceof QuadCurve2D) {
				QuadCurve2D l = (QuadCurve2D) s;
				if (cur==null || cur.getX()!=l.getX1() || cur.getY()!=l.getY1())
					p.moveTo(l.getX1(), l.getY1());
				p.quadTo(l.getCtrlX(), l.getCtrlY(), l.getX2(), l.getY2());
			} else if (s instanceof CubicCurve2D) {
				CubicCurve2D l = (CubicCurve2D) s;
				if (cur==null || cur.getX()!=l.getX1() || cur.getY()!=l.getY1())
					p.moveTo(l.getX1(), l.getY1());
				p.curveTo(l.getCtrlX1(), l.getCtrlY1(), l.getCtrlX2(), l.getCtrlY2(), l.getX2(), l.getY2());
			} else throw new IllegalArgumentException();
		}
	}
	

	public static void main(String[] args) {
		
	}
			
	
}