package org.simantics.plant3d.scenegraph.controlpoint;

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

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.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.datastructures.Pair;
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 double MIN_INLINE_LENGTH = 0.0005; // Minimum length of inline components, when component removal is not allowed. 

	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;
	

	// PathLeg iteration indicator. NEXT_S > NEXT > NONE  PREV_S > PREV > NONE 
	private enum PathLegUpdateType {
		NONE,   // Only current path leg needs to be updated  (for example, inline comp was moved)
		PREV,   // Current and previous path leg need to be updated 
		NEXT,   // Current and next path leg need to be updated
		PREV_S, // Current and previous two path legs need to be updated (turn was moved, which affect other path leg end turns, and thus following path legs
		NEXT_S  // Current and next two path legs need to be updated
	};
	
	private static boolean enabled = true;  // 
	private static boolean updating = false;
	private static boolean allowInsertRemove = true;
	private static boolean triedIR = false;

	
	private static List<PipeControlPoint> requestUpdates = new ArrayList<PipeControlPoint>();
	private static List<PipeControlPoint> currentUpdates = new ArrayList<PipeControlPoint>();
	
	private static Object updateMutex = new Object();
	private static Object ruleMutex = new Object();
	
	public static void requestUpdate(PipeControlPoint pcp) {
	    if (!PipingRules.enabled)
	        return;
		if (DEBUG) System.out.println("PipingRules request " + pcp);
		synchronized (updateMutex) {
			if (!requestUpdates.contains(pcp))
				requestUpdates.add(pcp);
		}
	}
	
	public static boolean update() throws Exception {
	    if (!PipingRules.enabled)
	        return false;
	    
	    List<PipeControlPoint> temp;
	    synchronized(updateMutex) {
			if (requestUpdates.size() == 0)
				return false;
			
			temp = new ArrayList<PipeControlPoint>(requestUpdates.size());
			temp.addAll(requestUpdates);
			requestUpdates.clear();
		}
		synchronized (ruleMutex) {
			currentUpdates.clear();
			currentUpdates.addAll(temp);
			// TODO : we should remove already processed control points from currentUpdates after each _positionUpdate call.
			for (PipeControlPoint pcp : currentUpdates)
				_positionUpdate(pcp, true);
			currentUpdates.clear();
		}
		synchronized(updateMutex) {
			requestUpdates.removeAll(temp);
		}
		
		return true;
	}
	
	public static boolean positionUpdate(PipeControlPoint pcp) throws Exception {
		
		return positionUpdate(pcp, true);
	}
	
	public static boolean positionUpdate(PipeControlPoint pcp, boolean allowIR) throws Exception {
		synchronized (ruleMutex) {
			currentUpdates.add(pcp);
			boolean b = _positionUpdate(pcp, allowIR);
			currentUpdates.clear();
			return b;
		}
		
	}
	
	private 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.getParentPoint() != null)
			    pcp = pcp.getParentPoint();
			if (pcp.asPathLegEnd()) {
				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) {
			synchronized (ruleMutex) {
				currentUpdates.clear();
			}
		}
	}
	
	public static boolean isEnabled() {
		return enabled;
	}

	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);
		
		if (pcp.isOffset()) {
			// Adjusting the rotation angle of an offset component may change variable angle turns
			PipeControlPoint end = pcp.findNextEnd();
			if (end.isVariableAngle()) {
				updatePathLegNext(end, end, PathLegUpdateType.NONE);
			}
			if (start.isVariableAngle()) {
				updatePathLegPrev(start, start, 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.getDualSub()) {
			pcp1 = pcp1.getDualSub();	
		} else if (pcp1.getPrevious() == pcp2 && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2;
			pcp2 = t;
		} else if (pcp2.isDualInline() && pcp1.getPrevious() == pcp2.getDualSub() && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2.getDualSub();
			pcp2 = t;
		} else {
			throw new RuntimeException();
		}
		TurnComponent elbow = ComponentUtils.createTurn((P3DRootNode)pcp1.getRootNode());
		PipeControlPoint pcp = elbow.getControlPoint();
		if (pcp1.isDualInline())
			pcp1 = pcp1.getDualSub();
		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.getDualSub()) {
			pcp1 = pcp1.getDualSub();	
		} else if (pcp1.getPrevious() == pcp2 && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2;
			pcp2 = t;
		} else if (pcp2.isDualInline() && pcp1.getPrevious() == pcp2.getDualSub() && pcp2.getNext() == pcp1) {
			PipeControlPoint t = pcp1;
			pcp1 = pcp2.getDualSub();
			pcp2 = t;
		} else {
			throw new RuntimeException();
		}
		InlineComponent component = ComponentUtils.createStraight((P3DRootNode)pcp1.getRootNode());
		PipeControlPoint scp = component.getControlPoint();
		if (pcp1.isDualInline())
			pcp1 = pcp1.getDualSub();
		String name = pcp1.getPipeRun().getUniqueName("Pipe");
		component.setName(name);
		pcp1.getPipeRun().addChild(component);
		
		scp.insert(pcp1, pcp2);

		scp.setWorldPosition(pos);
		Vector3d dir = new Vector3d();
		dir.sub(pcp2.getWorldPosition(), pcp1.getWorldPosition());
		updateControlPointOrientation(scp, dir);
		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.getDualSub();
		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 {
		UpdateStruct2 us = createUS(start, Direction.NEXT, 0, new ArrayList<ExpandIterInfo>(), updated);
		if (us == null) {
		    System.out.println("Null update struct " + start);
		    return; 
		}
		updatePathLeg(us, lengthChange);
	}
	
	private static void updatePathLegPrev(PipeControlPoint start, PipeControlPoint updated, PathLegUpdateType lengthChange) throws Exception {
		UpdateStruct2 us = createUS(start, Direction.PREVIOUS, 0, new ArrayList<ExpandIterInfo>(), updated);
		if (us == null) {
            System.out.println("Null update struct " + start);
            return; 
        }
		updatePathLeg(us, 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();
		}

	}

	public static boolean calculateDirectedOffset(Vector3d startPoint, Vector3d endPoint, PipeControlPoint start, ArrayList<PipeControlPoint> list, PipeControlPoint end, Vector3d dir, Vector3d offset) {
		return calculateOffset(startPoint, endPoint, start, list, end, dir, offset, true);
	}

	public static boolean calculateOffset(Vector3d startPoint, Vector3d endPoint, PipeControlPoint start, ArrayList<PipeControlPoint> list, PipeControlPoint end, Vector3d dir, Vector3d offset) {
		return calculateOffset(startPoint, endPoint, start, list, end, dir, offset, false);
	}
	
	private static boolean calculateOffset(Vector3d startPoint, Vector3d endPoint, PipeControlPoint start, ArrayList<PipeControlPoint> list, PipeControlPoint end, Vector3d dir, Vector3d offset, boolean directed) {
		List<PipeControlPoint> offsets = getOffsetPoints(start, list);
		if (offsets.size() == 0) {
			setZeroOffset(startPoint, endPoint, dir, offset);
			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 (true) {
				iter--;
				offset.set(0.0, 0.0, 0.0);
				
				for (PipeControlPoint icp : offsets) {
					Vector3d v = icp.getSizeChangeOffsetVector(dir);
					offset.add(v);
				}
				
				if (directed)
					break;
				
				Point3d nep = new Point3d(endPoint);
				nep.sub(offset);
				if (nep.distance(ep) < 0.0000000001 || iter <= 0) {
					break;
				}
				
				ep = nep;
				dir.set(ep);
				dir.sub(sp);
				l = dir.lengthSquared(); 
				if (l > MathTools.NEAR_ZERO)
					dir.scale(1.0/Math.sqrt(l));
			}
			
			if (DEBUG)
				System.out.println("calcOffset s:"+ startPoint + " e:" + endPoint + " d:" + dir + " o:"+offset) ;
			
			return true;
		}
	}
	
	public static void setZeroOffset(Vector3d startPoint, Vector3d endPoint, Vector3d dir, Vector3d offset) {
		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);
	}

	public static List<PipeControlPoint> getOffsetPoints(PipeControlPoint start, ArrayList<PipeControlPoint> list) {
		List<PipeControlPoint> offsets = new ArrayList<PipeControlPoint>(list.size());
		// Only start offset affects the calculation
		if (start.isOffset())
		    offsets.add(start);
		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!"));
		}
		return offsets;
	}

	private static UpdateStruct2 createUS(PipeControlPoint start, Direction direction, int iter, ArrayList<ExpandIterInfo> toRemove, PipeControlPoint updated) {
		ArrayList<PipeControlPoint> list = new ArrayList<PipeControlPoint>();
		PipeControlPoint end = null;
		if (direction == Direction.NEXT) {
			end = start.findNextEnd(list);
		} else {
			ArrayList<PipeControlPoint> prevList = new ArrayList<PipeControlPoint>();
			PipeControlPoint tend = start.findPreviousEnd(prevList);
			for (PipeControlPoint icp : prevList) {
				if (icp.isDualSub()) {
					list.add(0, icp.getParentPoint());
				} else {
					list.add(0, icp);
				}
			}  
			end = start;
			start = tend;
		}
		if (start == end)
			return null;
		boolean hasOffsets = false;
		Vector3d offset = new Vector3d();
		Vector3d startPoint = start.getWorldPosition();
		Vector3d endPoint = end.getWorldPosition();
		Vector3d dir = new Vector3d();
		hasOffsets = calculateOffset(startPoint, endPoint, start, list, end, dir, offset);
		return new UpdateStruct2(start, startPoint, list, end, endPoint, dir, offset, hasOffsets, iter, direction == Direction.PREVIOUS, toRemove, updated);
	}
	
	private static Vector3d pathLegDirection(PipeControlPoint start) {
		ArrayList<PipeControlPoint> list = new ArrayList<PipeControlPoint>();
		PipeControlPoint end = start.findNextEnd(list);
		if (start == end) {
			return start.getDirection(Direction.NEXT);
		}
		
		Vector3d offset = new Vector3d();
		Vector3d startPoint = start.getWorldPosition();
		Vector3d endPoint = end.getWorldPosition();
		Vector3d dir = new Vector3d();
		calculateOffset(startPoint, endPoint, start, list, end, dir, offset);
		return dir;
	}
	
	private static boolean asDirected(PipeControlPoint pcp, Direction direction) {
		if (pcp.isDirected())
			return true;
		if (pcp.asFixedAngle()) {
			if (!pcp._getReversed())
				return direction == Direction.NEXT;
			else
				return direction == Direction.PREVIOUS;
		}
		return false;
	}
	
	private static Vector3d direction(PipeControlPoint pcp, Direction direction) {
		return pcp.getDirection(direction);
	}
 
	private static void updatePathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange) throws Exception {
	    boolean rs = true;
	    boolean re = true;
	    if (lengthChange == PathLegUpdateType.NONE) {
	        rs = false;
	        re = false;
	    }
	    updatePathLeg(u, lengthChange, rs, re);
	}
	
	private static void updatePathLeg(UpdateStruct2 u, PathLegUpdateType lengthChange, boolean rs, boolean re) throws Exception {
		int directed = 0;
		if (asDirected(u.start, Direction.NEXT))
			directed++;
		if (asDirected(u.end, Direction.PREVIOUS))
			directed++;
		if (rs)
		    setErrorForce(u.start, null);
		if (re)
		    setErrorForce(u.end, null);
        for (PipeControlPoint pcp : u.list)
            setErrorForce(pcp, null);
		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() || u.start.asFixedAngle()|| u.end.asFixedAngle())
			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.
		    if (u.start.isTurn())
		        MathTools.mad(start, u.dir, u.start.getInlineLength());
		    if (u.end.isTurn())
		        MathTools.mad(end, u.dir, -u.end.getInlineLength());   
		}

		boolean recalcline = false;

		Vector3d sp = new Vector3d(start);
		Vector3d ep = new Vector3d(end);
		ep.sub(u.offset);
		
		if (u.start.isOffset()) {
		    Vector3d offset = u.start.getSizeChangeOffsetVector(u.dir);
		    updateOffsetPoint(u.start, offset);
            sp.add(offset);
            ep.add(offset);
		}
		    
		for (PipeControlPoint icp : u.list) {
			updateInlineControlPoint(icp, sp, ep, u.dir);
			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);
			}
		}
		
		if (!checkSizes)
			return;	

		// Collect all path leg points for updating variable length components. This list will also contain leg ends (usually turns)
        ArrayList<PipeControlPoint> pathLegPoints = new ArrayList<>();
        // Collect all fixed length components with their offsets. 
        ArrayList<Pair<PipeControlPoint,Vector3d>> fixedLengthPoints = new ArrayList<>();

        pathLegPoints.add(u.start);
        fixedLengthPoints.add(new Pair<PipeControlPoint, Vector3d>(u.start, new Vector3d()));
        Vector3d off = new Vector3d();
        for (PipeControlPoint icp : u.list) {
            pathLegPoints.add(icp);
            updateBranchControlPointBranches(icp);
            if (icp.isOffset()) {
                fixedLengthPoints.add(new Pair<PipeControlPoint, Vector3d>(icp, new Vector3d(off)));
                Vector3d  offset = icp.getSizeChangeOffsetVector(u.dir);
                off.add(offset);
            } else if (!icp.isVariableLength()) {
                fixedLengthPoints.add(new Pair<PipeControlPoint, Vector3d>(icp, new Vector3d(off)));
            }
        }
        pathLegPoints.add(u.end);
        fixedLengthPoints.add(new Pair<PipeControlPoint, Vector3d>(u.end, new Vector3d(off)));
        
		sp = new Vector3d(start);
		ep = new Vector3d(end);
		ep.sub(u.offset);
		
		updateFixedLengths(fixedLengthPoints, sp, ep, u.dir);
		
		for (int i = 0; i < pathLegPoints.size(); i++) {
			PipeControlPoint icp = pathLegPoints.get(i);

			PipeControlPoint prev = i > 0 ? pathLegPoints.get(i - 1) : null;
			PipeControlPoint next = i < pathLegPoints.size() - 1 ? pathLegPoints.get(i + 1) : null;
			
			if (prev != null && prev.isDualInline())
				prev = prev.getDualSub();		

			if (icp.isVariableLength()) {
				if (prev != null && next != null) {
					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 != null ? prev : next);
				}
			} else if (prev != null && !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);
		} 
		if (checkSizes) {
		    sp = new Vector3d(u.startPoint);
	        ep = new Vector3d(u.endPoint);
	        ep.sub(u.offset);
		    double pathLegLength = MathTools.distance(sp, ep);
            double availableLength = pathLegLength;
            if (u.start.isTurn())
                availableLength -= u.start.getInlineLength();
            if (u.end.isTurn())
                availableLength -= u.end.getInlineLength();
            for (PipeControlPoint pcp : u.list) {
                if (!pcp.isVariableLength())
                    availableLength-= pcp.getLength();
		    }
            if (availableLength < 0.0) {
                setError(u.start, "Not enough available space");
                setError(u.end, "Not enough available space");
                for (PipeControlPoint pcp : u.list)
                    setError(pcp, "Not enough available space");
            }
//            System.out.println(u.start.getPipelineComponent().toString() + " " + pathLegLength + " " + availableLength + " " + u.end.getPipelineComponent().toString() + " " + u.start.getInlineLength() + " " + u.end.getInlineLength());
		}
	}
	
	private enum Gap{ATTACHED,OVERLAP,SPACE};
	
	private static class GapObj {
	    Gap gap;
	    double d;
	    
	    Pair<PipeControlPoint,Vector3d> pcp1;
	    Pair<PipeControlPoint,Vector3d> pcp2;
	}
	
	private static void updateFixedLengths(List<Pair<PipeControlPoint,Vector3d>> fixedLengthPoints, Vector3d s, Vector3d e, Vector3d dir) {
	    double totalLength = MathTools.distance(s, e);
	    double reservedLength = 0.0;
	    List<Double> distances = new ArrayList<>(fixedLengthPoints.size());
	    distances.add(0.0);
	    for (int i = 1; i < fixedLengthPoints.size()-1; i++) {
	        Pair<PipeControlPoint,Vector3d> pcp = fixedLengthPoints.get(i);
	        reservedLength += pcp.first.getLength();
	        Vector3d p = pcp.first.getWorldPosition();
	        p.sub(pcp.second);
	        double d= MathTools.distance(s, p);
	        distances.add(d);
	    }
	    distances.add(totalLength);
	    
	    if (totalLength >= reservedLength) {
	        // There is enough space for all fixed length components.
	        List<GapObj> gaps = new ArrayList<>(fixedLengthPoints.size()-1);
	        int overlaps = 0;
	        // Analyze gaps between components
	        for (int i = 0; i < fixedLengthPoints.size()-1; i++) {
	            Pair<PipeControlPoint,Vector3d> pcp1 = fixedLengthPoints.get(i);
	            Pair<PipeControlPoint,Vector3d> pcp2 = fixedLengthPoints.get(i+1);
	            double d1 = distances.get(i);
	            double d2 = distances.get(i+1);
	            double ld1 = i == 0 ? 0.0 :pcp1.first.getInlineLength();
	            double ld2 = i == fixedLengthPoints.size()-2 ? 0.0 : pcp2.first.getInlineLength();
	            
	            double e1 = d1 + ld1; // End of comp1
	            double s2 = d2 - ld2; // Start of comp2
	            double diff =s2 - e1;
	            GapObj obj = new GapObj();
	            obj.pcp1 = pcp1;
	            obj.pcp2 = pcp2;
	            obj.d = diff;
	            if (diff < -MIN_INLINE_LENGTH) {
	                obj.gap = Gap.OVERLAP;
	                overlaps++;
	            } else if (diff > MIN_INLINE_LENGTH) {
	                obj.gap = Gap.SPACE;
	            } else {
	                obj.gap = Gap.ATTACHED;
	            }
	            gaps.add(obj);
	        }
	        // If there are no overlaps, there is nothing to do.
	        if (overlaps == 0)
	            return;
	        // Get rid of overlapping components by using closest available free spaces.
	        for (int i = 0; i < gaps.size(); i++) {
	            GapObj gapObj = gaps.get(i);
	            if (gapObj.gap != Gap.OVERLAP)
	                continue;
	            double curr = gapObj.d;
	            int d = 1;
	            while (d < gaps.size() && curr < -MIN_INLINE_LENGTH) {
	                GapObj next = i+d < gaps.size() ? gaps.get(i+d) : null;
                    GapObj prev = i-d >= 0 ? gaps.get(i-d) : null;
	                if (next != null && next.gap == Gap.SPACE) {
	                    double move = Math.min(-curr, next.d);
	                    curr+= move;
	                    next.d -= move;
	                    if (next.d < MIN_INLINE_LENGTH)
	                        next.gap = Gap.ATTACHED;
	                    Vector3d mv = new Vector3d(dir);
	                    mv.normalize();
	                    mv.scale(move);
	                    for (int j = i ; j < i+d; j++) {
	                        Pair<PipeControlPoint,Vector3d> pcp = gaps.get(j).pcp2;
	                        Vector3d p = new Vector3d(pcp.first.getWorldPosition());
	                        p.add(mv);
	                        pcp.first.setWorldPosition(p);
	                    }
	                }
	                else if (prev != null && prev.gap == Gap.SPACE) {
	                    double move = Math.min(-curr, prev.d);
                        curr+= move;
                        prev.d -= move;
                        if (prev.d < MIN_INLINE_LENGTH)
                            prev.gap = Gap.ATTACHED;
                        Vector3d mv = new Vector3d(dir);
                        mv.normalize();
                        mv.scale(-move);
                        for (int j = i ; j > i-d; j--) {
                            Pair<PipeControlPoint,Vector3d> pcp = gaps.get(j).pcp1;
                            Vector3d p = new Vector3d(pcp.first.getWorldPosition());
                            p.add(mv);
                            pcp.first.setWorldPosition(p);
                        }
	                }
	                else {
	                    d++;
	                }
	            }
	        }
	    } else {
            for (int i = 1; i < fixedLengthPoints.size()-1; i++) {
    	        Pair<PipeControlPoint,Vector3d> prev = i == 0 ? null : fixedLengthPoints.get(i-1);
    	        Pair<PipeControlPoint,Vector3d> curr = fixedLengthPoints.get(i);
    	        Pair<PipeControlPoint,Vector3d> next = i == fixedLengthPoints.size() -1 ? null : fixedLengthPoints.get(i+1);
                updateFixedLength(curr, prev, next, s,e, dir);
            }
	    }
	}
	
	private static void updateFixedLength(Pair<PipeControlPoint,Vector3d> icp, Pair<PipeControlPoint,Vector3d> prev,  Pair<PipeControlPoint,Vector3d> next, Vector3d s, Vector3d e, Vector3d dir) {
	    if (prev != null) {
	       checkOverlap(prev, icp, dir,true);
	    }
	    if (next != null)
	        checkOverlap(icp, next, dir,true);
	}
	
	private static boolean checkOverlap(Pair<PipeControlPoint,Vector3d> icp, Pair<PipeControlPoint,Vector3d> icp2, Vector3d dir, boolean se) {
	    Vector3d p1 = icp.first.getWorldPosition();
	    Vector3d p2 = icp2.first.getWorldPosition();
	    p1.add(icp.second);
	    p2.add(icp2.second);
	    double u[] = new double[1];
	    MathTools.closestPointOnStraight(p2, p1, dir, u);
	    if (u[0] < 0.0) {
	        p2.set(p1);
	        p2.sub(icp.second);
	        p2.add(icp2.second);
	        MathTools.mad(p2, dir, MIN_INLINE_LENGTH);
	        icp2.first.setWorldPosition(p2);
	    }
	    double d = MathTools.distance(p1, p2);
        double r = icp.first.getInlineLength() + icp2.first.getInlineLength();
        
	    if ((d-r) < - MIN_INLINE_LENGTH) {
            if (se) {
                setError(icp.first, "Overlapping");
                setError(icp2.first, "Overlapping");
            }
            return true;
        }
        return false;
	}
	
	/**
	 * Overrides current error of a component
	 * @param pcp
	 * @param error
	 */
	private static void setErrorForce(PipeControlPoint pcp, String error) {
	    PipelineComponent comp = pcp.getPipelineComponent();
        if (comp == null)
            return;
        comp.setError(error);
	}
	
	/**
	 * Sets error for a component, if there is no existing error.
	 * @param pcp
	 * @param error
	 */
	private static void setError(PipeControlPoint pcp, String error) {
	    PipelineComponent comp = pcp.getPipelineComponent();
	    if (comp == null)
	        return;
	    if (comp.getError() != null)
	        return;
	    comp.setError(error);
	}
	
	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.length();                // distance between control points
		double l2prev = prev.getInlineLength(); // distance taken by components
		double l2next = next.getInlineLength();
		double l2 = l2prev + l2next;
		double length = l - l2;                 // true length of the variable length component
		if (length >= MIN_INLINE_LENGTH) {      // check if there is enough space for variable length component.
			// components fit
			dir.normalize();
			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 (!allowInsertRemove) {
			        icp.setLength(MIN_INLINE_LENGTH);
			        setError(icp, "Not enough available space");
			        triedIR = true;
			        return false;
			    }
				if (DEBUG)
					System.out.println("PipingRules.updateVariableLength removing " + icp);
				icp._remove();
				return true;
			} else {
			    icp.setLength(MIN_INLINE_LENGTH);
			    icp.getPipelineComponent().setError("Not enough available space");
			}
			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;
		double diff = l - l2s;
		if (diff >= MIN_INLINE_LENGTH) {
			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);
				insertStraight(prev, icp, dir, length);
				return true;
			} else {
				triedIR = true;
			}
		}
		return false;
	}
	
	private static void updateVariableLengthEnd(PipeControlPoint icp,  PipeControlPoint prev) {
		Vector3d currentPos = icp.getWorldPosition();
		Vector3d prevPos = prev.getWorldPosition();
		
		Vector3d dir = new Vector3d();
		dir.sub(currentPos, prevPos);
		
		boolean simple;
		synchronized (ruleMutex) {
			simple = currentUpdates.contains(icp);
		}
		
		if (simple) {
			// Update based on position -> adjust length
			double currentLength = (dir.length() - prev.getInlineLength()) * 2.0;
			icp.setLength(currentLength);
		} else {
			// Update based on neighbour movement -> adjust length and position, so that free end stays in place.
			double currentLength = icp.getLength();
			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));
		}
	}

	/**
	 * Recalculates offset vector based on current direction, and calls checkExpandPathLeg
	 * @param u
	 * @param updateEnds
	 * @throws Exception
	 */
	private static void ppNoOffset(UpdateStruct2 u, boolean updateEnds) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.ppNoOffset() " + u);
		Vector3d offset = new Vector3d();
		if (u.hasOffsets) {
			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, updateEnds);
	}

	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, start, list, end, dir, offset);
		ppNoOffset(new UpdateStruct2(start, startPoint, list, end, endPoint, dir, null, hasOffsets, iter, reversed, toRemove, updated),true);
	}

	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 (asDirected(u.start, Direction.NEXT)) {
			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 = direction(dcp, dcpStart ? Direction.NEXT : Direction.PREVIOUS);
		if (directedDirection == null) {
			//updateTurnControlPointTurn(dcp, dcp.getPrevious(), dcp.getNext());
			updateTurnControlPointTurn(dcp, null, null);
			directedDirection = direction(dcp, dcpStart ? Direction.NEXT : Direction.PREVIOUS);
			if (directedDirection == null) {
				return;
			}
		}
		
		Point3d otherPosition = new Point3d(dcpStart ? u.endPoint : u.startPoint);
		if (u.hasOffsets) {
			Vector3d dir = new Vector3d(), offset = new Vector3d();
			calculateDirectedOffset(u.startPoint, u.endPoint, u.start, u.list, u.end, dir, offset);
			u.dir = dir;
			u.offset = offset;
			
			if (dcpStart)
				otherPosition.add(offset);
			else
				otherPosition.sub(offset);
		}

		double mu[] = new double[2];

		Vector3d closest;
		Vector3d t = new Vector3d();

		closest = MathTools.closestPointOnStraight(otherPosition, position, directedDirection, mu);
		t.sub(closest, otherPosition);

		double distance = t.length();
		boolean aligned = (distance < ALLOWED_OFFSET);
		double requiredSpace  = 0.0;
		if (other.isVariableAngle()) {
		    requiredSpace = spaceForTurn(other, dcp);
		}
		if (mu[0] < requiredSpace) {
		    // At the moment, if next component is directly behind the nozzle, we must force moving the other component.
		    // Trying to solve the situation by adding new turn creates infinite loop...   
		    aligned = false;
		    canMoveOther = true;
		}
		if (aligned) {
			//if (u.start.isInline() || u.end.isInline() || u.start.asFixedAngle() || u.end.asFixedAngle())
		    //    processPathLeg(u, true, false);
			checkExpandPathLeg(u, lengthChange, inlineEnd || u.start.isInline() || u.end.isInline() || u.start.asFixedAngle() || u.end.asFixedAngle());
		} 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] < requiredSpace) {
						if (dcpStart) {
							closest.set(u.startPoint);
						} else {
							closest.set(u.endPoint);
						}
						Vector3d v = new Vector3d(directedDirection);
						v.scale(requiredSpace);
						closest.add(v);
					}

					if (canMoveOther) {
						if (DEBUG)
							System.out.println("PipingRules.updateDirectedPipeRun() moved end " + other + " to " + closest);
						
						// Not aligned - we need to recalculate the offset to reflect new end points.
						Vector3d offset;
						if (u.hasOffsets) {
							offset = new Vector3d();
							Vector3d newDir = new Vector3d();
							calculateDirectedOffset(position, closest, u.start, u.list, u.end, newDir, offset);
							closest.add(offset);
						} else {
							offset = new Vector3d();
						}
						
						other.setWorldPosition(closest);
						
						if (dcpStart) {
							checkExpandPathLeg(new UpdateStruct2(u.start, u.startPoint, u.list, u.end, new Vector3d(closest), directedDirection, offset, u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated), PathLegUpdateType.NONE, true);
							if (u.end.getNext() != null)
								updatePathLegNext(u.end, u.updated, PathLegUpdateType.NEXT);
						} else {
							checkExpandPathLeg(new UpdateStruct2(u.start, new Vector3d(closest), u.list, u.end, u.endPoint, directedDirection, offset, u.hasOffsets, u.iter, u.reversed, u.toRemove, u.updated), PathLegUpdateType.NONE, true);
							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);
		
		Vector3d dir = new Vector3d(), offset = new Vector3d();
		calculateDirectedOffset(new Vector3d(position1), new Vector3d(position2), u.start, u.list, u.end, dir, offset);
		
		Point3d position1offset = new Point3d(position1);
		position1offset.add(offset);
		Point3d position2offset = new Point3d(position2);
		position2offset.sub(offset);
		Vector3d dir1 = direction(dcp1, Direction.NEXT);
		Vector3d dir2 = direction(dcp2, Direction.PREVIOUS);
		
		Vector3d p1 = MathTools.closestPointOnStraight(position1, position2offset, dir2);
		Vector3d p2 = MathTools.closestPointOnStraight(position2, position1offset, 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();
				Vector3d v = new Vector3d();
				if (!u.reversed)
					v.set(dir1);
				else
					v.set(dir2);
				
				// Reserve space for 90 deg elbow
				double off = dcp1.getPipeRun().getTurnRadius();
				v.scale(off);
				p1.add(v);

				if (!u.reversed)
					p2 = MathTools.closestPointOnStraight(new Point3d(p1), position2offset, dir2);
				else
					p2 = MathTools.closestPointOnStraight(new Point3d(p1), position1offset, dir1);

				// By default, the elbows are placed next to each other, by using 90 deg angles.
				// If the distance between elbows is not enough, we must move the other elbow (and create more shallow angle elbows)
				if (MathTools.distance(p1, p2) < off*2.05) {
					p2.add(v);
				}
				
				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, PipeControlPoint dcp) {
		// TODO : if the path legs contain offset, using just positions of opposite path leg ends is not enough.
	    // TODO : current iterative way for calculating required space may return longer length that is required.
		double tr = ((TurnComponent)tcp.getPipelineComponent()).getTurnRadius();
	    if (dcp == null)
	        return tr; // space for 90 deg
	    PipeControlPoint ne = tcp.findNextEnd();
	    PipeControlPoint pe = tcp.findPreviousEnd();
	    PipeControlPoint other = null;
	    if (dcp == ne)
	        other = pe;
	    else if (dcp == pe)
	        other = ne;
	    else
	        return tr; // space for 90 deg
	    if (other == null)
	        return tr; // space for 90 deg
	    Vector3d dir = dcp.getDirectedControlPointDirection();
	    Vector3d dir2;
	    if (other == ne) {
	    	dir2 = pathLegDirection(tcp);
	    } else {
	    	dir2 = pathLegDirection(pe);
	    	dir2.negate();
	    }

	    double d = dir.dot(dir2);
	    if (d > 0.9999)
	    	return 0.0; // point following turn is directly in the front of the nozzle.
	    else if (d < -0.9999)
            return tr*2.0; // point following turn is directly behind the nozzle, in theory, we should return Double.Inf...
	    
	    double curr = 0.0;
	    int iter = 10;
	    Vector3d tp0 = tcp.getPosition();
	    try {
		    Vector3d dp = dcp.getWorldPosition();
		    while (iter > 0) {
		        Vector3d tp = new Vector3d(dir);
		        tp.scaleAdd(curr, dp);
		        tcp._setPosition(tp); // no firing of listeners here
			    if (other == ne) {
			    	dir2 = pathLegDirection(tcp);
			    } else {
			    	dir2 = pathLegDirection(pe);
			    	dir2.negate();
			    }
			    
		        double a = dir.angle(dir2);
		        
		        // other is directly between dcp and tcp, a zero angle turn should do
		        if (Math.PI - a <= MathTools.NEAR_ZERO)
		            return 0.0;
		        
		        double R = tr * Math.tan(a * 0.5);
		        if (R <= curr)
		            break;
		        curr = R*1.001;
		        iter--;
		    }
	    }
	    finally {
	    	tcp._setPosition(tp0); // return the original value
	    }
	    return curr;
	}

	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 = new Vector3d(directedDirection);
		closest.scaleAdd(dcp.getPipeRun().getTurnRadius(), position);
		if (dcpStart) {
			tcp = insertElbow(dcp, next, closest);
		} else {
			tcp = insertElbow(next, dcp, closest);
		}
		
		double s = spaceForTurn(tcp,dcp);
		Vector3d p = new Vector3d(directedDirection);
		p.scaleAdd(s, position);
		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 = updateTurnControlPointTurn(u.start, null, u.dir);
				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) {
				// TODO: u.end, u.dir, null
				double a = updateTurnControlPointTurn(u.end, null, null);
				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 more 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());
				updateTurnControlPointTurn(u.start, null, null);
//				updatePathLegPrev(u.start, u.start, PathLegUpdateType.NONE);
			} else if (u.start.isEnd()) {
				updateEndComponentControlPoint(u.start, u.dir);
			} else if (u.start.isInline()) {
				updateControlPointOrientation(u.start, u.dir);
			}
			if (u.end.isTurn()) {
				//updateTurnControlPointTurn(u.end, u.end.getPrevious(), u.end.getNext());
				updateTurnControlPointTurn(u.end, null, null);
//				updatePathLegNext(u.end, u.end, PathLegUpdateType.NONE);
			} else if (u.end.isEnd()) {
				updateEndComponentControlPoint(u.end, u.dir);
			} else if (u.end.isInline()) {
				updateControlPointOrientation(u.end, u.dir);
			}

		} else {
			if (u.start.isEnd()) {
				updateEndComponentControlPoint(u.start, u.dir);
			}
			if (u.end.isEnd()) {
				updateEndComponentControlPoint(u.end, u.dir);
			}
		}
		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
	// {
	@SuppressWarnings("unused")
	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.getDualSub();
		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.getChildPoints())
				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, dir);
	}

	/**
	 * 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 dir) throws Exception {
		if (DEBUG)
			System.out.println("PipingRules.updateEndComponentControlPoint() " + ecp);
		
		if (!ecp.isFixed()) // prevent overriding nozzle orientations..
		   updateControlPointOrientation(ecp, dir);

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

	private static void updateControlPointOrientation(PipeControlPoint pcp, Vector3d dir) {
		Double angleO = pcp.getRotationAngle();
		double angle = 0.0;
		if (angleO != null)
			angle = angleO;
		boolean reversed = pcp._getReversed();
		Quat4d q = null;
		if (dir != null) {
		    q = pcp.getControlPointOrientationQuat(dir, angle, reversed);
		} else {
		    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.getChildPoints();
		if (branches.size() == 0) {
			if (DEBUG)
				System.out.println("No Branches found");
			return;
		}
		
		for (PipeControlPoint pcp : branches) {
			updatePathLegEndControlPoint(pcp);
		}
	}

	private static double updateTurnControlPointTurn(PipeControlPoint tcp, Vector3d prev, Vector3d next) {
		if (next == null) {
			UpdateStruct2 us = createUS(tcp, Direction.NEXT, 0, new ArrayList<PipingRules.ExpandIterInfo>(), tcp);
			if (us != null)
				next = us.dir;
		}
		if (prev == null) {
			UpdateStruct2 us = createUS(tcp, Direction.PREVIOUS, 0, new ArrayList<PipingRules.ExpandIterInfo>(), tcp);
			if (us != null) {
				prev = us.dir;
			}
		}
		
		if (!tcp.asFixedAngle()) {
			
			
			if (next == null || prev == null) {
				if (tcp.getTurnAngle() != null)
					return tcp.getTurnAngle();
				return Math.PI; // FIXME : argh
			}
			
			final boolean isDegenerate = prev.lengthSquared() < MathTools.NEAR_ZERO || next.lengthSquared() < MathTools.NEAR_ZERO;
			double turnAngle = isDegenerate ? 0.0 : prev.angle(next);
	
			Vector3d turnAxis = new Vector3d();
			turnAxis.cross(prev, next);
			if (turnAxis.lengthSquared() > MathTools.NEAR_ZERO) {
				double elbowRadius = ((TurnComponent)tcp.getPipelineComponent()).getTurnRadius();
				double R = elbowRadius * Math.tan(turnAngle * 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(new Vector3d(MathTools.Y_AXIS));
			}
			
			updateControlPointOrientation(tcp,prev);
			
			if (DEBUG)
				System.out.println("PipingTools.updateTurnControlPointTurn " + prev + " " + next + " " + turnAngle + " " + turnAxis);
			return turnAngle;
		} else {
			
			if (prev != null && next != null) {
				// Nothing to do
			} else if (prev == null) {
				if (!tcp._getReversed())
					tcp.setReversed(true);
			} else if (next == null) {
				if (tcp._getReversed())
					tcp.setReversed(false);
			}
			
			Vector3d dir = null;
			if (!tcp._getReversed()) {
				dir = prev;
			} else {
				dir = next;
				dir.negate();
			}
			if (dir == null) {
				return Math.PI; // FIXME : argh
			}
			
			Quat4d q = tcp.getControlPointOrientationQuat(dir, tcp.getRotationAngle() != null ? tcp.getRotationAngle() : 0.0);
			Vector3d v = new Vector3d();
			MathTools.rotate(q, MathTools.Y_AXIS,v);
			tcp.setTurnAxis(v);
			tcp.setWorldOrientation(q);
			if (tcp.getTurnAngle() != null)
				return tcp.getTurnAngle();
			return Math.PI; // FIXME : argh
		}
		
		
	}
	
	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 && prev.getPipeRun() != null) { // bypass possible corruption
			    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) {
		
		while (true) {
			List<PipeControlPoint> points = getControlPoints(pipeRun);
			PipeControlPoint pcp = points.get(0);
			if (pcp.isSizeChange() && pcp.getChildPoints().size() > 0) {
				PipeRun pr = pcp.getPipeRun();
				if (pr != pipeRun)
				    pipeRun = pr;
				else break;
			} else {
				break;
			}
		}
		List<PipeRun> all = new ArrayList<PipeRun>();
		List<List<PipeControlPoint>> pcps = new ArrayList<List<PipeControlPoint>>();
		while (true) {
			all.add(pipeRun);
			List<PipeControlPoint> points = getControlPoints(pipeRun);
			pcps.add(points);
			PipeControlPoint pcp = points.get(points.size()-1);
			if (pcp.getChildPoints().size() > 0) {
				PipeRun pipeRun2 = pcp.getChildPoints().get(0).getPipeRun();
				if (pipeRun == pipeRun2)
				    break;
				else
				    pipeRun = pipeRun2;
			} else {
				break;
			}
		}
		for (int i = 0 ; i < all.size(); i++) {
			List<PipeControlPoint> list = pcps.get(i);
			_reverse(list);
		}
		for (int i = 0 ; i < all.size(); i++) {
			boolean last = i == all.size() - 1;
			List<PipeControlPoint> list = pcps.get(i);
			
			if (!last) {
				List<PipeControlPoint> list2 = pcps.get(i+1);
				PipeControlPoint prev = list.get(list.size()-1);
				PipeControlPoint next = list2.get(0);
				if (prev == next) {
					// Reverse the component on the boundary.
					InlineComponent ic = (InlineComponent)prev.getPipelineComponent();
					PipeRun r1 = ic.getPipeRun();
					PipeRun r2 = ic.getAlternativePipeRun();
					if (r1 == null || r2 == null)
						throw new RuntimeException("Components on PipeRun changes should refer to bot PipeRuns");
					ic.deattach();
					r2.addChild(ic);
					ic.setPipeRun(r2);
					ic.setAlternativePipeRun(r1);
				} else {
					throw new RuntimeException("PipeRun changes should contain shared control points");
				}
				
			}
		}
			
	}
	
	private static void _reverse(List<PipeControlPoint> list) {
		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.getDualSub();
			if (first) {
				PipeControlPoint next = list.get(i+1);
				if (next.isDualInline())
					next = next.getDualSub();
				if (current.getNext() == next)
					current.setNext(null);
				current.setPrevious(next);
				if (currentSub != null) {
					if (currentSub.getNext() == next)
						currentSub.setNext(null);
					currentSub.setPrevious(next);       
				}
			} else if (last) {
				PipeControlPoint prev = list.get(i-1);
				
				if (current.getPrevious() == prev)
					current.setPrevious(null);
				current.setNext(prev);
				
				if (currentSub != null) {
					if (currentSub.getPrevious() == prev)
						currentSub.setPrevious(null);
					currentSub.setNext(prev);       
				}
			} else {
				PipeControlPoint prev = list.get(i-1);
				PipeControlPoint next = list.get(i+1);
				if (next.isDualInline())
					next = next.getDualSub();
				
				
				current.setPrevious(next);
				current.setNext(prev);
				
				if (currentSub != null) {
					currentSub.setPrevious(next);
					currentSub.setNext(prev);       
				}
				
			}
			//if (current.isTurn() && current.isFixed()) {
			if (current.asFixedAngle()) {
				current.setReversed(!current._getReversed());
			}
			if (current.isInline() && current.isReverse()) {
				current.setReversed(!current._getReversed());
			}   
		}
	}
	
	
	
	public static void validate(PipeRun pipeRun) {
		if (pipeRun == null)
			return;
		synchronized (ruleMutex) {
			Collection<PipeControlPoint> pcps = pipeRun.getControlPoints();
			int count = 0;
			//System.out.println("Validate " + pipeRun.getName());
			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 " + pipeRun.getName() + " contains unconnected control points, found " + runPcps.size() + " connected, " + pcps.size() + " total.");
				for (PipeControlPoint pcp : pcps) {
				    if (!runPcps.contains(pcp)) {
				        System.out.println("Unconnected " + pcp + " " + pcp.getPipelineComponent());
				    }
				}
			}
			for (PipeControlPoint pcp : pcps) {
			    if (pcp.getPipeRun() == null) {
			        System.out.println("PipeRun ref missing " + pcp + " " + pcp.getPipelineComponent());
			    }
				if (!pcp.isDirected() && pcp.getNext() == null && pcp.getPrevious() == null)
					System.out.println("Orphan undirected " + pcp + " " + pcp.getPipelineComponent());
			}
			for (PipeControlPoint pcp : pcps) {
				if (pcp.getParentPoint() == null) {
					PipeControlPoint sub = null;
					if (pcp.isDualInline())
						sub = pcp.getDualSub();
					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().isFixedLength());
		assert(!(newComponent instanceof  InlineComponent && !newComponent.getControlPoint().isFixedLength()));
		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 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);
		
		
		if (nextCP == null) {
			newCP.insert(splittingCP, Direction.NEXT);
			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);
			insertStraight(newCP, Direction.PREVIOUS, new Vector3d(vp), lp);
			splittingCP.setWorldPosition(new Vector3d(vn));
//			splittingCP.setRelatedScalarDouble(ProcessResource.plant3Dresource.HasLength, ln);
		} else {
			newCP.insert(splittingCP, nextCP);
			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.getDualSub();
		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);
		}
	}
}