package org.simantics.plant3d.scenegraph.controlpoint;

import java.util.ArrayList;
import java.util.Collection;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

import javax.vecmath.Point3d;
import javax.vecmath.Quat4d;
import javax.vecmath.Vector3d;

import org.simantics.g3d.math.MathTools;
import org.simantics.plant3d.scenegraph.InlineComponent;
import org.simantics.plant3d.scenegraph.Nozzle;
import org.simantics.plant3d.scenegraph.P3DRootNode;
import org.simantics.plant3d.scenegraph.PipeRun;
import org.simantics.plant3d.scenegraph.PipelineComponent;
import org.simantics.plant3d.scenegraph.TurnComponent;
import org.simantics.plant3d.scenegraph.controlpoint.PipeControlPoint.Direction;
import org.simantics.plant3d.utils.ComponentUtils;
import org.simantics.utils.ui.ErrorLogger;

public class PipingRules {
	private static final boolean DEBUG = false;
	private static final boolean DUMMY = false;

	private static double MIN_TURN_ANGLE = 0.001; // Threshold for removing turn components.
	private static double ALLOWED_OFFSET = 0.001; // Allowed offset for directed path legs

	private static final int REMOVE_NONE = 0;
	private static final int REMOVE_START = 1;
	private static final int REMOVE_END = 2;
	private static final int REMOVE_BOTH = 3;
	

	private enum PathLegUpdateType {
		NONE, PREV, NEXT, PREV_S, NEXT_S
	};
	
	private static boolean enabled = true;
	private static boolean updating = false;
	private static boolean allowInsertRemove = true;
	private static boolean triedIR = false;

	
	private static List<PipeControlPoint> updates = new ArrayList<PipeControlPoint>();
	
	private static Object mutex = new Object();
	
	public static void requestUpdate(PipeControlPoint pcp) {
		if (DEBUG) System.out.println("PipingRules request " + pcp);
		synchronized (mutex) {
		if (!updates.contains(pcp))
			updates.add(pcp);
		}
	}
	
	public static synchronized boolean update() throws Exception {
		if (updates.size() == 0)
			return false;
		List<PipeControlPoint> temp = new ArrayList<PipeControlPoint>(updates.size());
		synchronized(mutex) {
			temp.addAll(updates);
			updates.clear();
		}
		
		for (PipeControlPoint pcp : temp)
			positionUpdate(pcp);
		return true;
	}
	
	public static boolean positionUpdate(PipeControlPoint pcp) throws Exception {
		
		return positionUpdate(pcp, true);
	}
	
	public static boolean positionUpdate(PipeControlPoint pcp, boolean allowIR) throws Exception {
		if (updating || !enabled)
			return true;
		if (pcp.getPipeRun() == null)
			return false;
		try {
			if (DEBUG) System.out.println("PipingRules " + pcp);
			updating = true;
			allowInsertRemove = allowIR;
			triedIR = false;
			validate(pcp.getPipeRun());
			if (pcp.isPathLegEnd()) {
				updatePathLegEndControlPoint(pcp); // FIXME: Rules won't work properly, if they are not run twice.
				updatePathLegEndControlPoint(pcp);
			} else {
				updateInlineControlPoint(pcp);
				updateInlineControlPoint(pcp);
			}
			validate(pcp.getPipeRun());
			if (!allowInsertRemove)
				return !triedIR;
			return true;
		} finally {
			updating = false;
//			System.out.println("PipingRules done " + pcp);
		}
	}
	
	public static void setEnabled(boolean enabled) {
		PipingRules.enabled = enabled;
		if(!enabled)
			updates.clear();
	}
	
	public static boolean isEnabled() {
		return enabled;
	}
	
//	private void commit() {
//		root.getNodeMap().commit();
//	}

	public static class ExpandIterInfo {
		// these two are turn control points
		private PipeControlPoint start;
		private PipeControlPoint end;
		private int type;

		public ExpandIterInfo() {

		}

		public ExpandIterInfo(PipeControlPoint tcp, int type) {
			if (type == REMOVE_START)
				start = tcp;
			else
				end = tcp;
			this.type = type;
		}

		public ExpandIterInfo(PipeControlPoint start, PipeControlPoint end) {
			this.start = start;
			this.end = end;
			this.type = REMOVE_BOTH;
		}

		public PipeControlPoint getEnd() {
			return end;
		}

		public void setEnd(PipeControlPoint end) {
			this.end = end;
		}

		public PipeControlPoint getStart() {
			return start;
		}

		public void setStart(PipeControlPoint start) {
			this.start = start;
		}

		public int getType() {
			return type;
		}

		public void setType(int type) {
			this.type = type;
		}

	}

	private static void updatePathLegEndControlPoint(PipeControlPoint pcp) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updatePathLegEndControlPoint() " + pcp);
		if (pcp.getNext() != null) {
			updatePathLegNext(pcp, pcp, PathLegUpdateType.NEXT_S);
		}
		if (pcp.getPrevious() != null) {
			updatePathLegPrev(pcp, pcp, PathLegUpdateType.PREV_S);
		}

	}

	private static void updateInlineControlPoint(PipeControlPoint pcp) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updateInlineControlPoint() " + pcp);
		PipeControlPoint start = pcp.findPreviousEnd();
		updatePathLegNext(start, pcp, PathLegUpdateType.NONE);
	}

	private static PipeControlPoint insertElbow(PipeControlPoint pcp1, PipeControlPoint pcp2, Vector3d pos) throws Exception{
		if (DEBUG)
			System.out.println("PipingRules.insertElbow() " + pcp1 + " " + pcp2 + " " + pos);
		if (pcp1.getNext() == pcp2 && pcp2.getPrevious() == pcp1) {
			
		} else if (pcp1.getNext() == pcp2 && pcp1.isDualInline() && pcp2.getPrevious() == pcp1.getSubPoint().get(0)) {
			pcp1 = pcp1.getSubPoint().get(0);	
		} else if (pcp1.getPrevious() == pcp2 && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2;
			pcp2 = t;
		} else if (pcp2.isDualInline() && pcp1.getPrevious() == pcp2.getSubPoint().get(0) && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2.getSubPoint().get(0);
			pcp2 = t;
		} else {
			throw new RuntimeException();
		}
		TurnComponent elbow = ComponentUtils.createTurn((P3DRootNode)pcp1.getRootNode());
		PipeControlPoint pcp = elbow.getControlPoint();
		if (pcp1.isDualInline())
			pcp1 = pcp1.getSubPoint().get(0);
		String name = pcp1.getPipeRun().getUniqueName("Elbow");
		elbow.setName(name);
		pcp1.getPipeRun().addChild(elbow);

		pcp.insert(pcp1, pcp2);

		pcp.setWorldPosition(pos);
		validate(pcp.getPipeRun());
		return pcp;
	}
	
	private static PipeControlPoint insertStraight(PipeControlPoint pcp1, PipeControlPoint pcp2, Vector3d pos, double length) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.insertStraight() " + pcp1 + " " + pcp2 + " " + pos);
		if (pcp1.getNext() == pcp2 && pcp2.getPrevious() == pcp1) {
			
		} else if (pcp1.getNext() == pcp2 && pcp1.isDualInline() && pcp2.getPrevious() == pcp1.getSubPoint().get(0)) {
			pcp1 = pcp1.getSubPoint().get(0);	
		} else if (pcp1.getPrevious() == pcp2 && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2;
			pcp2 = t;
		} else if (pcp2.isDualInline() && pcp1.getPrevious() == pcp2.getSubPoint().get(0) && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2.getSubPoint().get(0);
			pcp2 = t;
		} else {
			throw new RuntimeException();
		}
		InlineComponent component = ComponentUtils.createStraight((P3DRootNode)pcp1.getRootNode());
		PipeControlPoint scp = component.getControlPoint();
		if (pcp1.isDualInline())
			pcp1 = pcp1.getSubPoint().get(0);
		String name = pcp1.getPipeRun().getUniqueName("Pipe");
		component.setName(name);
		pcp1.getPipeRun().addChild(component);
		
		scp.insert(pcp1, pcp2);

		scp.setWorldPosition(pos);
		scp.setLength(length);
		validate(scp.getPipeRun());
		return scp;
	}
	
	private static PipeControlPoint insertStraight(PipeControlPoint pcp, Direction direction , Vector3d pos, double length) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.insertStraight() " + pcp + " " + direction + " " + pos);
		
		InlineComponent component = ComponentUtils.createStraight((P3DRootNode)pcp.getRootNode());
		PipeControlPoint scp = component.getControlPoint();
		if (pcp.isDualInline() && direction == Direction.NEXT)
			pcp = pcp.getSubPoint().get(0);
		String name = pcp.getPipeRun().getUniqueName("Pipe");
		component.setName(name);
		pcp.getPipeRun().addChild(component);
		
		scp.insert(pcp,direction);

		scp.setWorldPosition(pos);
		scp.setLength(length);
		validate(scp.getPipeRun());
		return scp;
	}

	private static void updatePathLegNext(PipeControlPoint start, PipeControlPoint updated, PathLegUpdateType lengthChange) throws Exception {
		ArrayList<PipeControlPoint> list = new ArrayList<PipeControlPoint>();
		PipeControlPoint end = start.findNextEnd(list);
		// this is for inline cp that is also path leg end
		if (lengthChange == PathLegUpdateType.NONE) {
			if (start.equals(updated))
				lengthChange = PathLegUpdateType.NEXT;
			else if (end.equals(updated))
				lengthChange = PathLegUpdateType.PREV;
		}
		updatePathLegNext(start, list, end, updated, lengthChange);
	}

	private static void updatePathLegNext(PipeControlPoint start, ArrayList<PipeControlPoint> list, PipeControlPoint end, PipeControlPoint updated, PathLegUpdateType lengthChange) throws Exception {
		updatePathLeg(start, list, end, false, 0, new ArrayList<ExpandIterInfo>(), updated, lengthChange);
	}
	
	private static void updatePathLegPrev(PipeControlPoint start, PipeControlPoint updated, PathLegUpdateType lengthChange) throws Exception {
		ArrayList<PipeControlPoint> list = new ArrayList<PipeControlPoint>();
		PipeControlPoint end = start.findPreviousEnd(list);
		// TODO: this method is not symmetric with updatePathLegNext, which may alter lengthChange parameter?
		updatePathLegPrev(start, list, end, updated, lengthChange);
	}

	private static void updatePathLegPrev(PipeControlPoint start, ArrayList<PipeControlPoint> list, PipeControlPoint end, PipeControlPoint updated, PathLegUpdateType lengthChange) throws Exception {
		// reverses the list
		ArrayList<PipeControlPoint> nextList = new ArrayList<PipeControlPoint>();
		for (PipeControlPoint icp : list) {
			if (icp.isDualSub()) {
				nextList.add(0, icp.getParentPoint());
			} else {
				nextList.add(0, icp);
			}
		}
		updatePathLeg(end, nextList, start, true, 0, new ArrayList<ExpandIterInfo>(), updated, lengthChange);

	}

	private static class UpdateStruct2 {
		public PipeControlPoint start;
		public Vector3d startPoint;
		public ArrayList<PipeControlPoint> list;
		public PipeControlPoint end;
		public Vector3d endPoint;
		public Vector3d dir;
		public Vector3d offset;
		public boolean hasOffsets;
		public int iter;
		public boolean reversed;
		public ArrayList<ExpandIterInfo> toRemove;
		public PipeControlPoint updated;

		public UpdateStruct2(PipeControlPoint start, Vector3d startPoint, ArrayList<PipeControlPoint> list, PipeControlPoint end, Vector3d endPoint, Vector3d dir, Vector3d offset, boolean hasOffsets, int iter, boolean reversed, ArrayList<ExpandIterInfo> toRemove, PipeControlPoint updated) {
			if (start == null || end == null)
				throw new NullPointerException();
			this.start = start;
			this.startPoint = startPoint;
			this.list = list;
			this.end = end;
			this.endPoint = endPoint;
			this.dir = dir;
			this.offset = offset;
			this.hasOffsets = hasOffsets;
			this.iter = iter;
			this.reversed = reversed;
			this.toRemove = toRemove;
			this.updated = updated;
			
			if (!MathTools.isValid(startPoint) || 
				!MathTools.isValid(endPoint) || 
				!MathTools.isValid(dir)) {
				throw new RuntimeException();
			}
		}

		public String toString() {
			return start + " " + end+ " " + dir + " " + hasOffsets + " " + offset + " " + iter + " " + toRemove.size();
		}

	}

	private static boolean calculateOffset(Vector3d startPoint, Vector3d endPoint, ArrayList<PipeControlPoint> list, Vector3d dir, Vector3d offset) {
		boolean hasOffsets = false;
		List<PipeControlPoint> offsets = new ArrayList<PipeControlPoint>(list.size());
		for (PipeControlPoint icp : list) {
			if (icp.isOffset()) {
				offsets.add(icp);
			} else if (icp.isDualSub())
				ErrorLogger.defaultLogError("Updating pipe run, found offset controlpoint " + icp, new Exception("ASSERT!"));
		}
		if (offsets.size() == 0) {
			dir.set(endPoint);
			dir.sub(startPoint);
			double l = dir.lengthSquared(); 
			if (l > MathTools.NEAR_ZERO)
				dir.scale(1.0/Math.sqrt(l));
			offset.set(0.0, 0.0, 0.0);
			return false;
		} else {
			Vector3d sp = new Vector3d(startPoint);
			Point3d ep = new Point3d(endPoint);
			dir.set(ep);
			dir.sub(sp);
			double l = dir.lengthSquared(); 
			if (l > MathTools.NEAR_ZERO)
				dir.scale(1.0/Math.sqrt(l));
			int iter = 100;
			while (iter >= 0) {
				iter--;
				offset.set(0.0, 0.0, 0.0);
				
				for (PipeControlPoint icp : offsets) {
					Vector3d v = icp.getSizeChangeOffsetVector(dir);
					offset.add(v);
				}
				Point3d nep = new Point3d(endPoint);
				nep.sub(offset);
				if (nep.distance(ep) < 0.0000000001) {
					break;
				} 
				ep = nep;
				dir.set(ep);
				dir.sub(sp);
				l = dir.lengthSquared(); 
				if (l > MathTools.NEAR_ZERO)
					dir.scale(1.0/Math.sqrt(l));
			}
			hasOffsets = true;
		}
		
//		for (PipeControlPoint icp : list) {
//			if (icp.isOffset()) {
//				icp.setOffset(((InlineComponent)icp.getPipelineComponent()).getOffset());
//				hasOffsets = true;
//				Vector3d v = icp.getSizeChangeOffsetVector(dir);
//				offset.add(v);
//			} else if (icp.isDualSub())
//				ErrorLogger.defaultLogError("Updating pipe run, found offset controlpoint " + icp, new Exception("ASSERT!"));
//		}
		if (DEBUG && hasOffsets)
			System.out.println("calcOffset s:"+ startPoint + " e:" + endPoint + " d:" + dir + " o:"+offset) ;
		return hasOffsets;
	}

	/**
	 * @param start
	 *            starting point of the pipe run
	 * @param list
	 *            list of inline control points in the pipe run
	 * @param end
	 *            ending point of the pipe run
	 * @param reversed
	 *            boolean flag indicating wether start or end control point was
	 *            modified (if true then end point was modified)
	 * @throws TransactionException
	 */
	private static void updatePathLeg(PipeControlPoint start, ArrayList<PipeControlPoint> list, PipeControlPoint end, boolean reversed, int iter, ArrayList<ExpandIterInfo> toRemove, PipeControlPoint updated, PathLegUpdateType lengthChange) throws Exception {
		if (start == end)
			return;
		// FIXME: direction is calculated wrong way!
		boolean hasOffsets = false;
		Vector3d offset = new Vector3d();
		Vector3d startPoint = start.getWorldPosition();
		Vector3d endPoint = end.getWorldPosition();
		Vector3d dir = new Vector3d();
		hasOffsets = calculateOffset(startPoint, endPoint, list, dir, offset);
		updatePathLeg(new UpdateStruct2(start, startPoint, list, end, endPoint, dir, offset, hasOffsets, iter, reversed, toRemove, updated), lengthChange);

	}

	private static void updatePathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange) throws Exception {
		int directed = 0;
		if (u.start.isDirected())
			directed++;
		if (u.end.isDirected())
			directed++;
		switch (directed) {
		case 0:
			updateFreePathLeg(u, lengthChange);
			break;
		case 1:
			updateDirectedPathLeg(u, lengthChange);
			break;
		case 2:
			updateDualDirectedPathLeg(u, lengthChange);
			break;
		}

	}

	private static void updateFreePathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updateFreePipeRun " + u + " " + lengthChange);
		checkExpandPathLeg(u, lengthChange);
		if (u.start.isInline() || u.end.isInline())
			processPathLeg(u, true, false);
	}

	private static void updateInlineControlPoints(UpdateStruct2 u, boolean checkSizes) throws Exception{
		if (DEBUG)
			System.out.println("PipingRules.updateInlineControlPoints() " + u);

		Vector3d start = new Vector3d(u.startPoint);
		Vector3d end = new Vector3d(u.endPoint);
		
		if (checkSizes) {
			// create offsets for leg ends.
			MathTools.mad(start, u.dir, u.start.getInlineLength());
			MathTools.mad(end, u.dir, -u.end.getInlineLength());
		}
		
		boolean recalcline = false;
		if (!u.hasOffsets) {
			
			
			for (PipeControlPoint icp : u.list) {
				updateInlineControlPoint(icp, start, end, u.dir);
				
				if (icp.isOffset()) {
					// TODO : offset vector is already calculated and should be cached
					Vector3d off = icp.getSizeChangeOffsetVector(u.dir);
					updateOffsetPoint(icp, off);
				}
			}
			if (!checkSizes)
				return;			

			ArrayList<PipeControlPoint> pathLegPoints = new ArrayList<PipeControlPoint>();
			pathLegPoints.add(u.start);
			for (PipeControlPoint icp : u.list) {
				// updateInlineControlPoint(icp, u.startPoint,
				// u.endPoint,u.dir);
				updateBranchControlPointBranches(icp);
				pathLegPoints.add(icp);
			}
			pathLegPoints.add(u.end);

			// TODO : values can be cached in the loop
			for (int i = 1; i < pathLegPoints.size(); i++) {
				PipeControlPoint icp = pathLegPoints.get(i);

				PipeControlPoint prev = pathLegPoints.get(i - 1);
				

				if (icp.isVariableLength()) {
					if (i != pathLegPoints.size() - 1) {
						PipeControlPoint next = pathLegPoints.get(i + 1);
						recalcline = recalcline | updateVariableLength(icp,  prev, next);

					} else {
						// this is variable length component at the end of the
						// piperun.
						// the problem is that we want to keep unconnected end
						// of the component in the same
						// place, but center of the component must be moved.
						updateVariableLengthEnd(icp, prev);
					}


				} else if (!prev.isVariableLength()) {
					// If this and previous control point are not variable
					// length pcps, we'll have to check if there is no empty
					// space between them.
					// I there is, we'll have to create new variable length
					// component between them.
					recalcline = recalcline | possibleVaribleLengthInsert(icp, prev);
				}
			}
		} else { // with offset
			Vector3d sp = new Vector3d(start);
			Vector3d ep = new Vector3d(end);
			ep.sub(u.offset);
			
			ArrayList<PipeControlPoint> pathLegPoints = new ArrayList<PipeControlPoint>();
			pathLegPoints.add(u.start);

			for (PipeControlPoint icp : u.list) {
				updateInlineControlPoint(icp, sp, ep, u.dir);
				updateBranchControlPointBranches(icp);
				pathLegPoints.add(icp);
				if (icp.isOffset()) {
					// TODO : offset vector is already calculated and should be
					// cached
					Vector3d  offset = icp.getSizeChangeOffsetVector(u.dir);
					updateOffsetPoint(icp, offset);
					sp.add(offset);
					ep.add(offset);
				}
			}
			pathLegPoints.add(u.end);
			
			if (!checkSizes)
				return;	
			
			sp = new Vector3d(u.startPoint);
			ep = new Vector3d(u.endPoint);
			ep.sub(u.offset);
			
			for (int i = 1; i < pathLegPoints.size(); i++) {
				PipeControlPoint icp = pathLegPoints.get(i);

				PipeControlPoint prev = pathLegPoints.get(i - 1);
				if (prev.isDualInline())
					prev = prev.getSubPoint().get(0);
				

				if (icp.isVariableLength()) {
					if (i != pathLegPoints.size() - 1) {
						PipeControlPoint next;
						next = pathLegPoints.get(i + 1);
						recalcline = recalcline | updateVariableLength(icp,  prev, next);

					} else {
						// this is variable length component at the end of the
						// piperun.
						// the problem is that we want to keep unconnected end
						// of the component in the same
						// place, but center of the component must be moved.
						updateVariableLengthEnd(icp, prev);
					}
				} else if (!prev.isVariableLength()) {
					// If this and previous control point are not variable
					// length pcps, we'll have to check if there is no empty
					// space between them.
					// I there is, we'll have to create new variable length
					// component between them.
					recalcline = recalcline | possibleVaribleLengthInsert(icp, prev);
				}
				if (icp.isOffset()) {
					// TODO : offset vector is already calculated and should be
					// cached
					Vector3d  offset = icp.getSizeChangeOffsetVector(u.dir);
					sp.add(offset);
					ep.add(offset);
				}
			}
		}
		if (recalcline) {
			u.list.clear();
			u.start.findNextEnd(u.list);
		}
	}
	
	private static boolean updateVariableLength(PipeControlPoint icp, PipeControlPoint prev,  PipeControlPoint next) {
		Vector3d prevPos = prev.getWorldPosition();
		Vector3d nextPos = next.getWorldPosition();
		
		Vector3d dir = new Vector3d(nextPos);
		dir.sub(prevPos);
		double l = dir.lengthSquared(); // distance between
										// control points
										// (square)
		double l2prev = prev.getInlineLength(); // distance
																	// taken
																	// by
																	// components
		double l2next = next.getInlineLength();
		double l2 = l2prev + l2next;
		double l2s = MathTools.square(l2);
		if (l2s < l) { // check if there is enough space for
						// variable length component.
			// components fit
			dir.normalize();
			double length = Math.sqrt(l) - l2; // true length of
												// the variable
												// length
												// component
			dir.scale(length * 0.5 + l2prev); // calculate
												// center
												// position of
												// the component
			dir.add(prevPos);
			icp.setWorldPosition(dir);
			icp.setLength(length);
			return false;
		} else {
			// components leave no space to the component and it
			// must be removed
			
			if (icp.isDeletable()) {
				if (DEBUG)
					System.out.println("PipingRules.updateVariableLength removing " + icp);
				icp._remove();
				return true;
			}
			return false;
		}
	}
	
	private static boolean possibleVaribleLengthInsert(PipeControlPoint icp, PipeControlPoint prev) throws Exception{
		Vector3d currentPos = icp.getWorldPosition();
		Vector3d prevPos = prev.getWorldPosition();
		Vector3d dir = new Vector3d(currentPos);
		dir.sub(prevPos);
		double l = dir.lengthSquared();
		double l2prev = prev.getInlineLength();
		double l2next = icp.getInlineLength();
		double l2 = l2prev + l2next;
		double l2s = l2 * l2;
		if (l > l2s) {
			if (allowInsertRemove) {
				dir.normalize();
				double length = Math.sqrt(l) - l2; // true length of the
													// variable length
													// component
				dir.scale(length * 0.5 + l2prev); // calculate center
													// position of the
													// component
				dir.add(prevPos);
				PipeControlPoint scp = insertStraight(prev, icp, dir, length);
				return true;
			} else {
				triedIR = true;
			}
		}
		return false;
	}
	
	private static void updateVariableLengthEnd(PipeControlPoint icp,  PipeControlPoint prev) {
		double currentLength = icp.getLength();
		Vector3d currentPos = icp.getWorldPosition();
		Vector3d prevPos = prev.getWorldPosition();
		
		Vector3d dir = new Vector3d();
		dir.sub(currentPos, prevPos);
		
		if (currentLength < MathTools.NEAR_ZERO) {
			currentLength = (dir.length() - prev.getInlineLength()) * 2.0;
		}
		
		if (dir.lengthSquared() > MathTools.NEAR_ZERO)
			dir.normalize();
		Point3d endPos = new Point3d(dir);
		endPos.scale(currentLength * 0.5);
		endPos.add(currentPos); // this is the free end of the
								// component

		double offset = prev.getInlineLength();
		Point3d beginPos = new Point3d(dir);
		beginPos.scale(offset);
		beginPos.add(prevPos); // this is the connected end of
								// the component

		double l = beginPos.distance(endPos);
		
		if (Double.isNaN(l))
			System.out.println("Length for " + icp + " is NaN");

		dir.scale(l * 0.5);
		beginPos.add(dir); // center position

		if (DEBUG)
			System.out.println("PipingRules.updateInlineControlPoints() setting variable length to " + l);
		icp.setLength(l);

		icp.setWorldPosition(new Vector3d(beginPos));
	}

	private static void ppNoOffset(UpdateStruct2 u) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.ppNoOffset() " + u);
		Vector3d offset = new Vector3d();
		if (u.hasOffsets) {
			u.dir.normalize();
			for (PipeControlPoint icp : u.list) {
				if (icp.isOffset()) {
					offset.add(icp.getSizeChangeOffsetVector(u.dir));
				} else if (icp.isDualSub())
					ErrorLogger.defaultLogError("Updating pipe run, found offset controlpoint " + icp, new Exception("ASSERT!"));
			}
		}
		u.offset = offset;
		checkExpandPathLeg(u, PathLegUpdateType.NONE);
	}

	private static void ppNoDir(PipeControlPoint start, Vector3d startPoint, ArrayList<PipeControlPoint> list, PipeControlPoint end, Vector3d endPoint, boolean hasOffsets, int iter, boolean reversed, ArrayList<ExpandIterInfo> toRemove, PipeControlPoint updated) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.ppNoDir() " + start + " " + end + " " + iter + " " + toRemove.size());
		// FIXME : extra loop (dir should be calculated here)
		Vector3d dir = new Vector3d();
		Vector3d offset = new Vector3d();
		hasOffsets = calculateOffset(startPoint, endPoint, list, dir, offset);
		ppNoOffset(new UpdateStruct2(start, startPoint, list, end, endPoint, dir, null, hasOffsets, iter, reversed, toRemove, updated));
	}

	private static void checkExpandPathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange) throws Exception {
		checkExpandPathLeg(u, lengthChange, u.updated.isInline() && u.updated.isOffset());
	}
	
	private static void checkExpandPathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange, boolean updateEnds) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.checkExpandPathLeg() " + u + " " + lengthChange);
		if (lengthChange != PathLegUpdateType.NONE) {
			// FIXME : turns cannot be checked before inline cps are updated,
			// since their position affects calculation of turns
			processPathLeg(u, updateEnds, false);
			int type = checkTurns(u, lengthChange);
			if (type == REMOVE_NONE) {
				processPathLeg(u, updateEnds, true);
			} else {
				expandPathLeg(u, type);
			}
		} else {
			processPathLeg(u, updateEnds, true);
		}
	}

	private static void updateDirectedPathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updateDirectedPipeRun() " + u + " " + lengthChange);
		PipeControlPoint dcp;
		PipeControlPoint other;
		boolean canMoveOther = false;
		boolean dcpStart = false;
		boolean inlineEnd = false;
		Vector3d position;
		if (u.start.isDirected()) {
			dcp = u.start;
			other = u.end;
			position = u.startPoint;
			dcpStart = true;
			if (!u.reversed)
				canMoveOther = true;
			inlineEnd = u.end.isInline();
				
		} else {
			dcp = u.end;
			other = u.start;
			position = u.endPoint;
			if (u.reversed)
				canMoveOther = true;
			inlineEnd = u.start.isInline();
		}

		Vector3d directedDirection = dcp.getDirection();
		Point3d directedEndPoint = new Point3d(u.endPoint);
		if (u.hasOffsets)
			directedEndPoint.add(u.offset);

		double mu[] = new double[2];

		Vector3d closest;
		Vector3d t = new Vector3d();

		if (dcpStart) {
			closest = MathTools.closestPointOnStraight(directedEndPoint, u.startPoint, directedDirection, mu);
			t.sub(closest, directedEndPoint);
		} else {
			closest = MathTools.closestPointOnStraight(u.startPoint, directedEndPoint, directedDirection, mu);
			t.sub(closest, u.startPoint);
		}

		double distance = t.length();
		boolean aligned = (distance < ALLOWED_OFFSET);
		if (aligned) {
			checkExpandPathLeg(u, lengthChange, inlineEnd);
			
		} else {
			if (u.iter > 0) {
				backIter(u);
			} else {
				PipeControlPoint nextToMoved;

				if (u.list.size() > 0)
					if (dcpStart)
						nextToMoved = u.list.get(0);
					else
						nextToMoved = u.list.get(u.list.size() - 1);
				else if (dcpStart)
					nextToMoved = u.end;
				else
					nextToMoved = u.start;
				if (other.isVariableAngle()) {

					// TODO calculate needed space from next run end.
					if (mu[0] < 1.0) {
						if (dcpStart) {
							closest.set(u.startPoint);
						} else {
							closest.set(u.endPoint);
						}
						Vector3d v = new Vector3d(directedDirection);
						v.scale(spaceForTurn(other));
						closest.add(v);
					}

					if (canMoveOther) {
						if (DEBUG)
							System.out.println("PipingRules.updateDirectedPipeRun() moved end " + other + " to " + closest);
						other.setWorldPosition(closest);
						if (dcpStart) {
							ppNoOffset(new UpdateStruct2(u.start, u.startPoint, u.list, u.end, new Vector3d(closest), directedDirection, null, u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated));
							if (u.end.getNext() != null)
								updatePathLegNext(u.end, u.updated, PathLegUpdateType.NEXT);
						} else {
							ppNoOffset(new UpdateStruct2(u.start, new Vector3d(closest), u.list, u.end, u.endPoint, directedDirection, null, u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated));
							if (u.start.getPrevious() != null)
								updatePathLegPrev(u.start, u.updated, PathLegUpdateType.PREV);
						}
					} else {
						// TODO : calculate needed space from next run end.
						if (allowInsertRemove)
							insertElbowUpdate(u, dcp, nextToMoved, dcpStart, position, directedDirection);
							
						else
							triedIR = true;
					}
				} else if (other.isNonDirected() && other.getParentPoint() != null) {
					// FIXME : this code was for updating branches
					Vector3d bintersect = new Vector3d();
					PipeControlPoint bcp = other.getParentPoint();
					if (bcp != null && canMoveOther) {
						Point3d bstart = new Point3d();
						Point3d bend = new Point3d();
						Vector3d bdir = new Vector3d();
						bcp.getInlineControlPointEnds(bstart, bend, bdir);
						Vector3d nintersect = new Vector3d();

						MathTools.intersectStraightStraight(position, directedDirection, bend, bdir, nintersect, bintersect, mu);
						Vector3d dist = new Vector3d(nintersect);
						dist.sub(bintersect);
						canMoveOther = mu[1] > 0.0 && mu[1] < 1.0 && dist.lengthSquared() < 0.01;
					} else {
						// TODO : endControlPoints are undirected: calculcate
						// correct position for it
						throw new UnsupportedOperationException("not implemented");
					}
					if (canMoveOther) {
						if (DEBUG)
							System.out.println("PipingRules.updateDirectedPipeRun() moved end " + other + " to " + bintersect);
						// is required branch position is in possible range
						bcp.setWorldPosition(bintersect);
						if (dcpStart) {
							checkExpandPathLeg(new UpdateStruct2(u.start, u.startPoint, u.list, u.end, new Vector3d(bintersect), directedDirection, u.offset, u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated), lengthChange);
						} else {
							checkExpandPathLeg(new UpdateStruct2(u.start, new Vector3d(bintersect), u.list, u.end, u.endPoint, directedDirection, u.offset, u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated), lengthChange);
						}
					} else {
						// branch cannot be moved into right position, new turn
						// / elbow must be inserted
						if (allowInsertRemove)
							insertElbowUpdate(u, dcp, nextToMoved, dcpStart, position, directedDirection);
						else
							triedIR = true;
					}

				} else { // assume that control point cannot be moved, but can
							// be rotated
					if (allowInsertRemove)
						insertElbowUpdate(u, dcp, nextToMoved, dcpStart, position, directedDirection);
					else
						triedIR = true;
				}
			}
		}
		
		
	}

	private static void updateDualDirectedPathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updateDualDirectedPipeRun() " + u + " " + lengthChange);
		
		PipeControlPoint dcp1 = u.start;
		PipeControlPoint dcp2 = u.end;
		Point3d position1 = new Point3d(u.startPoint);
		Point3d position2 = new Point3d(u.endPoint);
		Point3d position1offset = new Point3d(position1);
		position1offset.sub(u.offset);
		Point3d position2offset = new Point3d(position2);
		position2offset.add(u.offset);
		Vector3d dir1 = dcp1.getDirection();
		Vector3d dir2 = dcp2.getDirection();
		Vector3d p1 = MathTools.closestPointOnStraight(position1offset, position2, dir2);
		Vector3d p2 = MathTools.closestPointOnStraight(position2offset, position1, dir1);
		double d1 = position1.distance(new Point3d(p1));
		double d2 = position2.distance(new Point3d(p2));

		boolean aligned = (d1 < ALLOWED_OFFSET && d2 < ALLOWED_OFFSET);
		if (aligned) {
			processPathLeg(u);
		} else {
			if (u.iter > 0) {
				backIter(u);
			} else if (allowInsertRemove){
				PipeControlPoint dcp;
				PipeControlPoint next;
				if (!u.reversed) {
					dcp = dcp1;
					if (u.list.size() > 0)
						next = u.list.get(0);
					else
						next = dcp2;
				} else {
					dcp = dcp2;
					if (u.list.size() > 0)
						next = u.list.get(u.list.size() - 1);
					else
						next = dcp1;
				}
				
				p1 = dcp.getWorldPosition();
				// FIXME: calculate position of the elbows properly.
				if (!u.reversed)
					p1.add(dir1);
				else
					p1.add(dir2);

				if (!u.reversed)
					p2 = MathTools.closestPointOnStraight(new Point3d(p1), position2, dir2);
				else
					p2 = MathTools.closestPointOnStraight(new Point3d(p1), position1, dir1);

				
				PipeControlPoint tcp1 = insertElbow(dcp, next, p1);
				PipeControlPoint tcp2 = insertElbow(tcp1, next, p2);

				if (DEBUG)
					System.out.println("PipingRules.updateDualDirectedPipeRun() created two turns " + tcp1 + " " + tcp2);

				if (!u.reversed) {
					Vector3d dd = new Vector3d(p2);
					dd.sub(p1);
					dir2.negate();
					updatePathLegNext(u.start, u.updated, PathLegUpdateType.NONE);
					updatePathLegNext(tcp1, u.updated, PathLegUpdateType.NONE);
					if (!u.reversed)
						updatePathLegNext(tcp2, u.updated, PathLegUpdateType.NONE);
					else
						updatePathLegPrev(tcp2, u.updated, PathLegUpdateType.NONE);
				} else {
					Vector3d dd = new Vector3d(p1);
					dd.sub(p2);
					dir2.negate();
					updatePathLegNext(tcp1, u.updated, PathLegUpdateType.NONE);
					updatePathLegNext(tcp2, u.updated, PathLegUpdateType.NONE);
					if (!u.reversed)
						updatePathLegNext(u.start, u.updated, PathLegUpdateType.NONE);
					else
						updatePathLegPrev(u.start, u.updated, PathLegUpdateType.NONE);
				}
			} else {
				triedIR = true;
			}
		}
		
	}
	
	private static double spaceForTurn(PipeControlPoint tcp) {
		// TODO : this returns now space for 90 deg turn.
		// The challenge: position of tcp affects the turn angle, which then affects the required space. Perhaps we need to iterate...
		// Additionally, if the path legs contain offset, using just positions of opposite path leg ends is not enough,    
		return tcp.getPipeRun().getTurnRadius();
	}

	private static void insertElbowUpdate(UpdateStruct2 u, PipeControlPoint dcp, PipeControlPoint next, boolean dcpStart, Vector3d position, Vector3d directedDirection) throws Exception{

		
//		Vector3d closest = new Vector3d(position);
//		closest.add(directedDirection);
		
		PipeControlPoint tcp = null;
		Vector3d closest;
		if (dcpStart) {
			closest = MathTools.closestPointOnStraight(next.getWorldPosition(), position, directedDirection);
			tcp = insertElbow(dcp, next, closest);
		} else {
			closest = MathTools.closestPointOnStraight(dcp.getWorldPosition(), position, directedDirection);
			tcp = insertElbow(next, dcp, closest);
		}
		// TODO properly calculate required distance between start and inserted elbow.
		double d = MathTools.distance(position, closest);
		double s = spaceForTurn(tcp);
		if (d < s)  {
			d = s - d;
			Vector3d p = new Vector3d(directedDirection);
			p.scale(d);
			p.add(closest);
			tcp.setPosition(p);
			closest = p;
		}
		
		

		if (DEBUG)
			System.out.println("PipingRules.updateDirectedPipeRun() inserted " + tcp);

		if (dcpStart) {
			// update pipe run from new turn to other end
			ppNoDir(tcp, new Vector3d(closest), u.list, u.end, u.endPoint, u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated);
			// update pipe run from directed to new turn
			processPathLeg(new UpdateStruct2(u.start, u.startPoint, new ArrayList<PipeControlPoint>(), tcp, new Vector3d(closest), directedDirection, new Vector3d(), false, 0, false, new ArrayList<ExpandIterInfo>(), u.updated));
		} else {
			// update pipe run from other end to new turn
			ppNoDir(u.start, u.startPoint, u.list, tcp, new Vector3d(closest), u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated);
			// update pipe run from new turn to directed
			processPathLeg(new UpdateStruct2(tcp, new Vector3d(closest), new ArrayList<PipeControlPoint>(), u.end, u.endPoint, directedDirection, new Vector3d(), false, 0, false, new ArrayList<ExpandIterInfo>(), u.updated));
		}
	}

	/**
	 * Checks if turns can be removed (turn angle near zero)
	 */
	private static int checkTurns(UpdateStruct2 u, PathLegUpdateType lengthChange) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.checkTurns() " + u.start + " " + u.end);
		boolean startRemoved = false;
		boolean endRemoved = false;
		if (u.start.isVariableAngle()) {
			// this won't work properly if inline control points are not updated
			PipeControlPoint startPrev = u.start.getPrevious();
			if (startPrev != null) {
				double a;
				if (!u.hasOffsets) {
					a = updateTurnControlPointTurn(u.start, startPrev, u.end);
				} else {
					Vector3d ep = new Vector3d(u.endPoint);
					ep.sub(u.offset);
					a = updateTurnControlPointTurn(u.start, u.startPoint, startPrev.getPosition(), ep);

				}
				if (a < MIN_TURN_ANGLE && u.start.isDeletable())
					startRemoved = true;
				else if (lengthChange == PathLegUpdateType.PREV || lengthChange == PathLegUpdateType.PREV_S) {
					PathLegUpdateType type;
					if (lengthChange == PathLegUpdateType.PREV_S)
						type = PathLegUpdateType.PREV;
					else
						type = PathLegUpdateType.NONE;
					updatePathLegPrev(u.start, u.start, type);
				}
			}
		}
		if (u.end.isVariableAngle()) {

			PipeControlPoint endNext = u.end.getNext();
			if (endNext != null) {
				double a;
				if (!u.hasOffsets) {
					a = updateTurnControlPointTurn(u.end, u.start, endNext);
				} else {
					Vector3d sp = new Vector3d(u.startPoint);
					sp.add(u.offset);
					a = updateTurnControlPointTurn(u.end, u.endPoint, sp, endNext.getPosition());
				}
				if (a < MIN_TURN_ANGLE && u.end.isDeletable())
					endRemoved = true;
				else if (lengthChange == PathLegUpdateType.NEXT || lengthChange == PathLegUpdateType.NEXT_S) {
					PathLegUpdateType type;
					if (lengthChange == PathLegUpdateType.NEXT_S)
						type = PathLegUpdateType.NEXT;
					else
						type = PathLegUpdateType.NONE;
					updatePathLegNext(u.end, u.end, type);
				}
			}
		}
		if (DEBUG)
			System.out.println("PipingRules.checkTurns() res " + startRemoved + " " + endRemoved);
		if (!startRemoved && !endRemoved)
			return REMOVE_NONE;
		if (startRemoved && endRemoved)
			return REMOVE_BOTH;
		if (startRemoved)
			return REMOVE_START;
		return REMOVE_END;
	}

	/**
	 * Expands piperun search over turns that are going to be removed
	 * 
	 */
	private static void expandPathLeg(UpdateStruct2 u, int type) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.expandPipeline " + u.start + " " + u.end);
		ArrayList<PipeControlPoint> newList = new ArrayList<PipeControlPoint>();
		switch (type) {
		case REMOVE_NONE:
			throw new RuntimeException("Error in piping rules");
		case REMOVE_START:
			u.toRemove.add(new ExpandIterInfo(u.start, REMOVE_START));
			u.start = u.start.findPreviousEnd();
			u.startPoint = u.start.getPosition();
			u.start.findNextEnd(newList);
			newList.addAll(u.list);
			u.list = newList;
			break;
		case REMOVE_END:
			u.toRemove.add(new ExpandIterInfo(u.end, REMOVE_END));
			u.end = u.end.findNextEnd(newList);
			u.endPoint = u.end.getPosition();
			u.list.addAll(newList);
			break;
		case REMOVE_BOTH:
			u.toRemove.add(new ExpandIterInfo(u.start, u.end));
			u.start = u.start.findPreviousEnd();
			u.startPoint = u.start.getPosition();
			u.start.findNextEnd(newList);
			newList.addAll(u.list);
			u.list = newList;
			newList = new ArrayList<PipeControlPoint>();
			u.end = u.end.findNextEnd(newList);
			u.endPoint = u.end.getPosition();
			u.list.addAll(newList);
			break;
		default:
			throw new RuntimeException("Error in piping rules");

		}
		u.offset = new Vector3d();
		if (u.hasOffsets) {
			u.dir.normalize();
			for (PipeControlPoint icp : u.list) {
				if (icp.isOffset()) {
					u.offset.add(icp.getSizeChangeOffsetVector(u.dir));
				} else if (icp.isDualSub())
					ErrorLogger.defaultLogError("Updating pipe run, found offset controlpoint " + icp, new Exception("ASSERT!"));
			}
		}
		if (DEBUG)
			System.out.println("PipingRules.expandPipeline expanded " + u.start + " " + u.end);
		u.iter++;
		updatePathLeg(u, PathLegUpdateType.NONE);
	}

	/**
	 * reverts one iteration of turn removing back)
	 */
	private static void backIter(UpdateStruct2 u) throws Exception {

		if (DEBUG)
			System.out.println("PipingRules.backIter" + u.start + " " + u.end);
		if (u.iter == 0)
			throw new RuntimeException("Error in piping rules");
		ExpandIterInfo info = u.toRemove.get(u.toRemove.size() - 1);
		u.toRemove.remove(u.toRemove.size() - 1);
		if (info.getType() == REMOVE_START || info.getType() == REMOVE_BOTH) {
			while (u.list.size() > 0) {
				PipeControlPoint icp = u.list.get(0);
				if (icp.getPrevious().equals(info.getStart()))
					break;
				u.list.remove(icp);
			}
			u.start = info.getStart();
		}
		if (info.getType() == REMOVE_END || info.getType() == REMOVE_BOTH) {
			while (u.list.size() > 0) {
				PipeControlPoint icp = u.list.get(u.list.size() - 1);
				if (icp.getNext().equals(info.getEnd()))
					break;
				u.list.remove(icp);
			}
			u.end = info.getEnd();
		}
		u.offset = new Vector3d();
		if (u.hasOffsets) {
			u.dir.normalize();
			for (PipeControlPoint icp : u.list) {
				if (icp.isOffset()) {
					u.offset.add(icp.getSizeChangeOffsetVector(u.dir));
				} else if (icp.isDualSub())
					ErrorLogger.defaultLogError("Updating pipe run, found offset controlpoint " + icp, new Exception("ASSERT!"));
			}
		}
		processPathLeg(u);

	}

	/**
	 * Processes pipe run (removes necessary turns and updates run ends)
	 */
	// private static void processPathLeg(PipeControlPoint start, Point3d
	// startPoint,ArrayList<InlineControlPoint> list, PipeControlPoint
	// end,Point3d endPoint, Vector3d dir,Vector3d offset, boolean
	// hasOffsets,int iter, boolean reversed, ArrayList<ExpandIterInfo>
	// toRemove) throws TransactionException {

	private static void processPathLeg(UpdateStruct2 u) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.processPathLeg " + u.start + " " + u.end);
		processPathLeg(u, true, true);
	}

	private static void processPathLeg(UpdateStruct2 u, boolean updateEnds, boolean updateInline) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.processPathLeg " + (updateEnds ? "ends " : "") + (updateInline ? "inline " : "") + u.start + " " + u.end);

		if (u.toRemove.size() > 0) {
			for (ExpandIterInfo info : u.toRemove) {
				if (info.getStart() != null) {
					if (DEBUG)
						System.out.println("PipingRules.processPathLeg removing start " + info.getStart());
					info.getStart()._remove();
				}
				if (info.getEnd() != null) {
					if (DEBUG)
						System.out.println("PipingRules.processPathLeg removing end " + info.getEnd());
					info.getEnd()._remove();
				}
			}
			// ControlPointTools.removeControlPoint may remove mo0re than one
			// CP;
			// we must populate inline CP list again.
			u.list.clear();
			u.start.findNextEnd( u.list);
		}
		// FIXME : inline CPs are update twice because their positions must be
		// updated before and after ends.
		updateInlineControlPoints(u, false);
		
		if (updateEnds) {
			if (u.start.isTurn()) {
				updateTurnControlPointTurn(u.start, u.start.getPrevious(), u.start.getNext());
//				updatePathLegPrev(u.start, u.start, PathLegUpdateType.NONE);
			} else if (u.start.isEnd()) {
				updateEndComponentControlPoint(u.start, u.startPoint, u.endPoint);
			} else if (u.start.isInline()) {
				updateControlPointOrientation(u.start);
			}
			if (u.end.isTurn()) {
				updateTurnControlPointTurn(u.end, u.end.getPrevious(), u.end.getNext());
//				updatePathLegNext(u.end, u.end, PathLegUpdateType.NONE);
			} else if (u.end.isEnd()) {
				updateEndComponentControlPoint(u.end, u.startPoint, u.endPoint);
			} else if (u.end.isInline()) {
				updateControlPointOrientation(u.end);
			}

		} else {
			if (u.start.isEnd()) {
				updateEndComponentControlPoint(u.start, u.startPoint, u.endPoint);
			}
			if (u.end.isEnd()) {
				updateEndComponentControlPoint(u.end, u.startPoint, u.endPoint);
			}
		}
		if (updateInline)
			updateInlineControlPoints(u, true);

	}

	/**
	 * Processes pipe run and recalculates offset
	 */
	// private static void processPathLeg(PipeControlPoint start, Point3d
	// startPoint,ArrayList<InlineControlPoint> list, PipeControlPoint
	// end,Point3d endPoint, Vector3d dir, boolean hasOffsets,int iter, boolean
	// reversed, ArrayList<ExpandIterInfo> toRemove) throws TransactionException
	// {
	private static void processPathLegNoOffset(UpdateStruct2 u) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.processPathLeg " + u.start + " " + u.end);
		Vector3d offset = new Vector3d();
		if (u.hasOffsets) {
			u.dir.normalize();
			for (PipeControlPoint icp : u.list) {
				if (icp.isOffset()) {
					offset.add(icp.getSizeChangeOffsetVector(u.dir));
				} else if (icp.isDualSub()) {
					ErrorLogger.defaultLogError("Updating pipe run, found offset controlpoint " + icp, new Exception("ASSERT!"));
				}
			}
		}
		processPathLeg(u);
	}

	private static void updateOffsetPoint(PipeControlPoint sccp, Vector3d offset) {
		Vector3d world = sccp.getWorldPosition();
		world.add(offset);
		PipeControlPoint ocp = sccp.getSubPoint().iterator().next();
		ocp.setWorldPosition(world);
	}

	/**
	 * Updates InlineControlPoints position when straight pipe's end(s) have
	 * been changed)
	 * 
	 * @param pipeline
	 * @param icp
	 * @param nextPoint
	 * @param prevPoint
	 */
	private static void updateInlineControlPoint(PipeControlPoint icp, Vector3d prev, Vector3d next,  Vector3d dir) {
		if (DEBUG)
			System.out.println("PipingRules.updateInlineControlPoint() " + icp);

		Vector3d inlinePoint = icp.getWorldPosition();
		Vector3d prevPoint = new Vector3d(prev);
		Vector3d nextPoint = new Vector3d(next);
		if (!icp.isVariableLength()) {
			// Reserve space for fixed length components. 
			MathTools.mad(prevPoint, dir, icp.getInlineLength());
			MathTools.mad(nextPoint, dir, -icp.getInlineLength());
			if (MathTools.distance(prevPoint, nextPoint) < ALLOWED_OFFSET) {
				prevPoint = prev;
				nextPoint = next;
			}
		}
		boolean canCalc = MathTools.distance(prevPoint, nextPoint) > ALLOWED_OFFSET;
		if (DEBUG)
			System.out.print("InlineControlPoint update " + icp + " " + inlinePoint + " " + prevPoint + " " + nextPoint);
		Vector3d newInlinePoint = null;
		if (canCalc) {
			boolean branchUpdate = false;
			PipeControlPoint becp = null;
			for (PipeControlPoint pcp : icp.getSubPoint())
				if (pcp.isNonDirected()) {
					branchUpdate = true;
					becp = pcp;
					break;
				}
	
			if (DUMMY || !branchUpdate) {
				newInlinePoint = MathTools.closestPointOnEdge(new Vector3d(inlinePoint), prevPoint, nextPoint);
				
			} else {
	
				// FIXME : can only handle one branch
				PipeControlPoint p = null;
				if (becp.getNext() != null) {
					p = becp.findNextEnd();
				} else if (becp.getPrevious() != null) {
					p = becp.findPreviousEnd();
				}
				if (p == null) {
					newInlinePoint = MathTools.closestPointOnEdge(new Vector3d(inlinePoint), prevPoint, nextPoint);
				} else if (canCalc){
					Vector3d branchLegEnd = p.getWorldPosition();
					Vector3d dir2 = new Vector3d(inlinePoint);
					dir2.sub(branchLegEnd);
					Vector3d dir1 = new Vector3d(nextPoint);
					dir1.sub(prevPoint);
					newInlinePoint = new Vector3d();
					double mu[] = new double[2];
					MathTools.intersectStraightStraight(new Vector3d(prevPoint), dir1, new Vector3d(branchLegEnd), dir2, newInlinePoint, new Vector3d(), mu);
					if (DEBUG)
						System.out.println(mu[0]);
					// FIXME : reserve space
					if (mu[0] < 0.0) {
						newInlinePoint = new Vector3d(prevPoint);
					} else if (mu[0] > 1.0) {
						newInlinePoint = new Vector3d(nextPoint);
					}
				}
			}
		} else {
			// prevPoint == nextPoint
			newInlinePoint = new Vector3d(prevPoint);
		}
		if (DEBUG)
			System.out.println(" " + newInlinePoint);

		icp.setWorldPosition(newInlinePoint);
		updateControlPointOrientation(icp);
	}

	/**
	 * Updates InlineControlPoints position when straight pipe's end(s) have
	 * been changed)
	 * 
	 * @param pipeline
	 * @param icp
	 * @param nextPoint
	 * @param prevPoint
	 */
	private static void updateEndComponentControlPoint(PipeControlPoint ecp, Vector3d start, Vector3d end) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updateEndComponentControlPoint() " + ecp);
		// PipeControlPoint next = ecp.getNext();
		// PipeControlPoint prev = ecp.getPrevious();
		// if (next != null) {
		// end = G3DTools.getPoint(next.getLocalPosition());
		// start = G3DTools.getPoint(ecp.getLocalPosition());
		// } else if (prev != null) {
		// end = G3DTools.getPoint(ecp.getLocalPosition());
		// start = G3DTools.getPoint(prev.getLocalPosition());
		// } else {
		// // TODO : warning?
		// return;
		// }
		// Vector3d dir = new Vector3d (end);
		// dir.sub(start);
		// dir.normalize();
		// G3DTools.setTuple(ecp.getDirection(), dir);
		if (!ecp.isFixed())
			updateControlPointOrientation(ecp);

		for (PipeControlPoint pcp : ecp.getSubPoint()) {
			// TODO update position
			updatePathLegEndControlPoint(pcp);
		}
	}

	private static void updateControlPointOrientation(PipeControlPoint pcp) {
		// FIXME : hack to bypass variable length components orientation
//		if (pcp.getAtMostOneRelatedObject(ProcessResource.g3dResource.HasWorldOrientation) == null)
//			return;
//		if (pcp.rotationAngle == null)
//			return;
		Double angleO = pcp.getRotationAngle();
		double angle = 0.0;
		if (angleO != null)
			angle = angleO;
		Boolean reversedO = pcp.getReversed();
		boolean reversed = false;
		if (reversedO != null)
			reversed = reversedO;
		Quat4d q = pcp.getControlPointOrientationQuat(angle, reversed);
		pcp.setWorldOrientation(q);
	}

	/**
	 * Updates all branches when branch's position has been changed
	 * 
	 * @param bcp
	 */
	private static void updateBranchControlPointBranches(PipeControlPoint bcp) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updateBranchControlPointBranches() " + bcp);
		if (bcp.isDualInline())
			return;
		Collection<PipeControlPoint> branches = bcp.getSubPoint();
		if (branches.size() == 0) {
			if (DEBUG)
				System.out.println("No Branches found");
			return;
		}
		
		for (PipeControlPoint pcp : branches) {
			updatePathLegEndControlPoint(pcp);
		}
	}

	/**
	 * Recalculates turn control point's internal data (turn angle and offset)
	 * 
	 * @param tcp
	 * @param prev
	 * @param next
	 */
	private static double updateTurnControlPointTurn(PipeControlPoint tcp, PipeControlPoint prev, PipeControlPoint next) {
		if (DEBUG)
			System.out.println("PipingTools.updateTurnControlPointTurn()" + tcp);
		if (next == null || prev == null)
			return Math.PI; // FIXME : argh
		Vector3d middlePoint = tcp.getWorldPosition();
		Vector3d nextPoint = next.getWorldPosition();
		Vector3d prevPoint = prev.getWorldPosition();
		return updateTurnControlPointTurn(tcp, middlePoint, prevPoint, nextPoint);
	}

	/**
	 * Recalculates turn control point's internal data (turn angle and offset)
	 * 
	 * @param tcp
	 * @param middlePoint
	 * @param nextPoint
	 * @param prevPoint
	 */
	private static double updateTurnControlPointTurn(PipeControlPoint tcp, Vector3d middlePoint, Vector3d prevPoint, Vector3d nextPoint) {

		Vector3d dir1 = new Vector3d(middlePoint);
		dir1.sub(prevPoint);
		Vector3d dir2 = new Vector3d(nextPoint);
		dir2.sub(middlePoint);
		if (DEBUG)
			System.out.println("PipingTools.updateTurnControlPointTurn " + tcp + " " + prevPoint + " " + middlePoint + " " + nextPoint);
		return updateTurnControlPointTurn(tcp, dir1, dir2);
	}

	private static double updateTurnControlPointTurn(PipeControlPoint tcp, Vector3d dir1, Vector3d dir2) {
		double turnAngle = dir1.angle(dir2);

		double angle = Math.PI - turnAngle;

		Vector3d turnAxis = new Vector3d();
		turnAxis.cross(dir1, dir2);
		if (turnAxis.lengthSquared() > MathTools.NEAR_ZERO) {
			double elbowRadius = tcp.getPipelineComponent().getPipeRun().getTurnRadius();
			double R = elbowRadius / Math.tan(angle * 0.5);
			
			turnAxis.normalize();
			tcp.setTurnAngle(turnAngle);
			tcp.setLength(R);// setComponentOffsetValue(R);
			tcp.setTurnAxis(turnAxis);
//			tcp.setPosition(tcp.getPosition());
		} else {
			turnAngle = 0.0;
			tcp.setTurnAngle(0.0);
			tcp.setLength(0.0);
			tcp.setTurnAxis(MathTools.Y_AXIS);
		}
		updateControlPointOrientation(tcp);
		if (DEBUG)
			System.out.println("PipingTools.updateTurnControlPointTurn " + dir1 + " " + dir2 + " " + turnAngle + " " + turnAxis);
		return turnAngle;
	}
	
	public static List<PipeControlPoint> getControlPoints(PipeRun pipeRun) {
		List<PipeControlPoint> list = new ArrayList<PipeControlPoint>();
		if (pipeRun.getControlPoints().size() == 0)
			return list;
		PipeControlPoint pcp = pipeRun.getControlPoints().iterator().next();
		while (pcp.getPrevious() != null) {
			PipeControlPoint prev = pcp.getPrevious();
			if (prev.getPipeRun() != pipeRun)
				break;
			pcp = prev;
		}
		if (pcp.isDualSub()) {
			pcp = pcp.getParentPoint();
		}
		list.add(pcp);
		while (pcp.getNext() != null) {
			pcp = pcp.getNext();
			if (pcp.getPipeRun() != pipeRun)
				break;
			list.add(pcp);
		}
		return list;
	}
	
	public static void reverse(PipeRun pipeRun) {
		List<PipeControlPoint> list = getControlPoints(pipeRun);
		if (list.size() <= 1)
			return; // nothing to do.
		
		for (int i = 0 ; i < list.size(); i++) {
			boolean first = i == 0;
			boolean last = i == list.size() - 1;
			PipeControlPoint current = list.get(i);
			PipeControlPoint currentSub = null;
			if (current.isDualInline())
				currentSub = current.getSubPoint().get(0);
			if (first) {
				PipeControlPoint next = list.get(i+1);
				if (next.isDualInline())
					next = next.getSubPoint().get(0);
				current.setNext(null);
				current.setPrevious(next);
				if (currentSub != null) {
					currentSub.setNext(null);
					currentSub.setPrevious(next);		
				}
			} else if (last) {
				PipeControlPoint prev = list.get(i-1);
				
				current.setPrevious(null);
				current.setNext(prev);
				
				if (currentSub != null) {
					currentSub.setPrevious(null);
					currentSub.setNext(prev);		
				}
			} else {
				PipeControlPoint prev = list.get(i-1);
				PipeControlPoint next = list.get(i+1);
				if (next.isDualInline())
					next = next.getSubPoint().get(0);
				
				
				current.setPrevious(next);
				current.setNext(prev);
				
				if (currentSub != null) {
					currentSub.setPrevious(next);
					currentSub.setNext(prev);		
				}
				
			}
		}
	}
	
	public static void merge(PipeRun run1, PipeRun r2) {
		Map<PipeControlPoint, Vector3d> positions = new HashMap<PipeControlPoint, Vector3d>();
		Map<PipeControlPoint, Quat4d> orientations = new HashMap<PipeControlPoint, Quat4d>();
		for (PipeControlPoint pcp : r2.getControlPoints()) {
			positions.put(pcp, pcp.getWorldPosition());
			orientations.put(pcp, pcp.getWorldOrientation());
		}
		for (PipeControlPoint pcp : r2.getControlPoints()) {
			r2.deattachChild(pcp);
			run1.addChild(pcp);
			PipelineComponent component = pcp.getPipelineComponent();
			if (component != null) {
				if (!(component instanceof Nozzle)) {
					component.deattach();
					run1.addChild(component);
				} else {
					Nozzle n = (Nozzle)component;
					n.setPipeRun(run1);
				}
			}
		}
		r2.remove();
		
	}
	
	public static void validate(PipeRun pipeRun) {
		if (pipeRun == null)
			return;
		Collection<PipeControlPoint> pcps = pipeRun.getControlPoints();
		int count = 0;
		for (PipeControlPoint pcp : pcps) {
			if (pcp.getParentPoint() == null || pcp.getParentPoint().getPipeRun() != pipeRun)
				count++;
		}
		List<PipeControlPoint> runPcps = getControlPoints(pipeRun);
		if (runPcps.size() != count) {
			System.out.println("Run is not connected");
		}
		for (PipeControlPoint pcp : pcps) {
			if (!pcp.isDirected() && pcp.getNext() == null && pcp.getPrevious() == null)
				System.out.println("Orphan undirected " + pcp);
		}
		for (PipeControlPoint pcp : pcps) {
			if (pcp.getParentPoint() == null) {
				PipeControlPoint sub = null;
				if (pcp.isDualInline())
					sub = pcp.getSubPoint().get(0);
				PipeControlPoint next = pcp.getNext();
				PipeControlPoint prev = pcp.getPrevious();
				if (next != null) {
					if (!(next.getPrevious() == pcp || next.getPrevious() == sub)) {
						System.out.println("Inconsistency between " + pcp + " -> " +next );
					}
				}
				if (prev != null) {
					PipeControlPoint prevParent = null;
					if (prev.isDualSub()) {
						prevParent = prev.getParentPoint();
					} else if (prev.isDualInline()) {
						System.out.println("Inconsistency between " + pcp + " <-- " +prev );
					}
					if (!(prev.getNext() == pcp && (prevParent == null || prevParent.getNext() == pcp))) {
						System.out.println("Inconsistency between " + pcp + " <-- " +prev );
					}
				}
			}
		}
	}
	
	public static void splitVariableLengthComponent(PipelineComponent newComponent, InlineComponent splittingComponent, boolean assignPos) throws Exception{
		assert(!splittingComponent.getControlPoint().isFixed());
		assert(!(newComponent instanceof  InlineComponent && !newComponent.getControlPoint().isFixed()));
		PipeControlPoint newCP = newComponent.getControlPoint();
		PipeControlPoint splittingCP = splittingComponent.getControlPoint();
		PipeControlPoint nextCP = splittingCP.getNext();
		PipeControlPoint prevCP = splittingCP.getPrevious();
		
		/* there are many different cases to insert new component when
		   it splits existing VariableLengthinlineComponent.
	    
	       1. VariableLengthComponet is connected from both sides:
	          - insert new component between VariableLength component and component connected to it
	          - insert new VariableLengthComponent between inserted component and component selected in previous step
		
		   2. VariableLengthComponent is connected from one side
		     - Use previous case or:
		     - Insert new component to empty end
		     - Insert new VariableLength component to inserted components empty end
		     
		   3. VariableLength is not connected to any component.
		     - Should not be possible, at least in current implementation.
		     - Could be done using second case

		*/
		
		if (nextCP == null && prevCP == null) {
			// this should not be possible
			throw new RuntimeException("VariableLengthComponent " + splittingComponent + " is not connected to anything.");
		}
		double reservedLength = splittingComponent.getControlPoint().getLength();
		double newLength = newComponent.getControlPoint().getLength();
		
		
		Point3d next = new Point3d();
		Point3d prev = new Point3d();
		splittingCP.getInlineControlPointEnds(prev, next);
		
		Vector3d newPos = null;
		if (assignPos) {
			newPos = new Vector3d(prev);
			Vector3d dir = new Vector3d(next);
			dir.sub(prev);
			dir.scale(0.5);
			newPos.add(dir);
			newComponent.setWorldPosition(newPos);
		} else {
			newPos = newComponent.getWorldPosition();
		}
		
		

		Vector3d dir = new Vector3d(next);
		dir.sub(prev);
		dir.normalize();
		dir.scale(newLength * 0.5);
		Point3d vn = new Point3d(newPos);
		Point3d vp = new Point3d(newPos);
		vn.add(dir);
		vp.sub(dir);
		double ln = vn.distance(next);
		double lp = vp.distance(prev);
		vp.interpolate(prev, 0.5);
		vn.interpolate(next, 0.5);
		
		
		PipeControlPoint newVariableLengthCP = null;//insertStraight(pcp1, pcp2, pos, length);
		if (nextCP == null) {
			newCP.insert(splittingCP, Direction.NEXT);
			newVariableLengthCP = insertStraight(newCP, Direction.NEXT, new Vector3d(vn), ln);
			splittingCP.setWorldPosition(new Vector3d(vp));
//			ControlPointTools.setWorldPosition(splittingCP, vp);
//			splittingCP.setRelatedScalarDouble(ProcessResource.plant3Dresource.HasLength, lp);
		} else if (prevCP == null) {
			newCP.insert(splittingCP, Direction.PREVIOUS);
			newVariableLengthCP = insertStraight(newCP, Direction.PREVIOUS, new Vector3d(vp), lp);
			splittingCP.setWorldPosition(new Vector3d(vn));
//			splittingCP.setRelatedScalarDouble(ProcessResource.plant3Dresource.HasLength, ln);
		} else {
			newCP.insert(splittingCP, nextCP);
			newVariableLengthCP = insertStraight(newCP, nextCP, new Vector3d(vn), ln);
			splittingCP.setWorldPosition(new Vector3d(vp));
//			splittingCP.setRelatedScalarDouble(ProcessResource.plant3Dresource.HasLength, lp);
		}
		positionUpdate(newCP);

	}
	
	public static void addSizeChange(boolean reversed, PipeRun pipeRun, PipeRun other, InlineComponent reducer, PipeControlPoint previous, PipeControlPoint next) {
		PipeControlPoint pcp = reducer.getControlPoint();
		PipeControlPoint ocp = pcp.getSubPoint().get(0);
		if (!reversed) {
			String name = pipeRun.getUniqueName("Reducer");
			reducer.setName(name);
			pipeRun.addChild(reducer);
			other.addChild(ocp);
			reducer.setAlternativePipeRun(other);
			
			previous.setNext(pcp);
			pcp.setPrevious(previous);
			ocp.setPrevious(previous);
			if (next != null) {
				pcp.setNext(next);
				ocp.setNext(next);
				next.setPrevious(ocp);
			}
		} else {
			String name = other.getUniqueName("Reducer");
			reducer.setName(name);
			other.addChild(reducer);
			pipeRun.addChild(ocp);
			reducer.setAlternativePipeRun(pipeRun);
			
			if (next != null) {
				next.setNext(pcp);
				pcp.setPrevious(next);
				ocp.setPrevious(next);
			}
			pcp.setNext(previous);
			ocp.setNext(previous);
			previous.setPrevious(ocp);
		}
	}
}