/*
 * Copyright 1998-2008 Sun Microsystems, Inc.  All Rights Reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.  Sun designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Sun in the LICENSE file that accompanied this code.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 */

package javax.media.j3d;

import java.util.Collection;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Vector;

/**
 * The CompileState holds information used during a compile.  It is
 * passed to each SceneGraphObject (SGO) during the compile.  Each SGO
 * modifies the CompileState as necessary and passes the CompileState
 * to its children (if any).
 *
 * The CompileState currently has two functions: appearance mapping
 * and shape merging.
 *
 * Appearance mapping maintains a list of the unique appearances seen
 * during the compile.  getAppearance() is used to turn multiple,
 * equivalent and static appearances into a single shared appearance.
 *
 * The shape mergings collects shapes that are potentially mergable
 * during a compile.  The shapes are sorted into a Map of Lists of
 * shapes, using the shape's appearance as the key.  After a subtree
 * is traversed, the shapes are merged and added to the Group.
 */

class CompileState {
// Appearance mapping stuff:
private final HashMap<AppearanceRetained, AppearanceRetained> knownAppearances;
    int numShapes = 0;

// Shape merging stuff:
private final HashMap<AppearanceRetained, Vector<Shape3DRetained>> shapeLists;
    int	numMergeSets = 0;
    int	numMergeShapes = 0;

    static final int BOUNDS_READ		= 0x00001;
    static final int GEOMETRY_READ		= 0x00002;


    // scene graph flattening

    boolean keepTG = false;	// used to force the immediate transform
				// group to stay around

    boolean needNormalsTransform = false;  // true if the current transform
		 			   // needs to push down normals
					   // transform to geometries

				// the current static transform group
    TransformGroupRetained staticTransform = null;

				// parent group
    GroupRetained parentGroup = null;

    int numTransformGroups = 0;
    int numStaticTransformGroups = 0;
    int numMergedTransformGroups = 0;
    int numGroups = 0;
    int numMergedGroups = 0;
    int numShapesWSharedGeom = 0;
    int numShapesWStaticTG = 0;
    int numLinks = 0;
    int numSwitches = 0;
    int numOrderedGroups = 0;
    int numMorphs = 0;

CompileState() {
	knownAppearances = new HashMap<AppearanceRetained, AppearanceRetained>();
	shapeLists = new HashMap<AppearanceRetained, Vector<Shape3DRetained>>();
}

    // Appearance mapping:
/**
 * Returns an unique appearance which equals app. If appearance does not equal
 * any previously found, the appearance will be added to the known appearances
 * and be returned. If the apperance equals a previously known appearance, then
 * the prevously known apperance will be returned
 */
AppearanceRetained getAppearance(AppearanceRetained app) {
	// see if the appearance has allready been classified
	if (app.map == this && app.mapAppearance != null) {
		return app.mapAppearance;
	}

	// check if this appearance equals one one in the Map
	AppearanceRetained retval = knownAppearances.get(app);
	if (retval == null) {
		// not found, put this appearance in the map
		knownAppearances.put(app, app);
		retval = app;
	}

	// cache this result on the appearance in case it appears again
	app.map = this;
	app.mapAppearance = retval;

	return retval;
}

    void addShape(Shape3DRetained shape) {
	if (parentGroup != null) {
	    // sort the shapes into lists with equivalent appearances
		Vector<Shape3DRetained> list = shapeLists.get(shape.appearance);
		if (list == null) {
			list = new Vector<Shape3DRetained>();
			shapeLists.put(shape.appearance, list);
		}
	    // Add the shape to the list only if at its parent level
	    // no children can be added or removed ..
	    // Look for the first non-null geometry, there should be atleast
	    // one otherwise it wouldn't come here
	    GeometryRetained geometry = null;
	    int i = 0;
	    while (geometry == null && i < shape.geometryList.size()) {
			geometry = shape.geometryList.get(i);
		i++;
	    }
	    if (shape.parent instanceof GroupRetained && ((GroupRetained)shape.parent).isStaticChildren() && geometry.geoType < GeometryArrayRetained.GEO_TYPE_RASTER) {
		list.add(shape);
	    }

	}
    }


    void printStats() {
	System.err.println("numTransformGroups= " + numTransformGroups);
	System.err.println("numStaticTransformGroups= " + numStaticTransformGroups);
	System.err.println("numMergedTransformGroups= " + numMergedTransformGroups);
	System.err.println("numGroups= " + numGroups);
	System.err.println("numMergedGroups= " + numMergedGroups);
	System.err.println("numShapes= " + numShapes);
	System.err.println("numShapesWStaticTG= " + numShapesWStaticTG);
	System.err.println("numMergeShapes= " + numMergeShapes);
	System.err.println("numMergeSets= " + numMergeSets);
	System.err.println("numLinks= " + numLinks);
	System.err.println("numSwitches= " + numSwitches);
	System.err.println("numOrderedGroups= " + numOrderedGroups);
	System.err.println("numMorphs= " + numMorphs);
    }

    void doShapeMerge() {

	//	System.err.println("doShapeMerge, shapeList = "+shapeLists);
	if (shapeLists != null) {
	    // loop over the shapes in each list, creating a single shape
	    // for each.  Add the shape to the group
		Collection<Vector<Shape3DRetained>> lists = shapeLists.values();
		Iterator<Vector<Shape3DRetained>> listIterator = lists.iterator();
	    Shape3DRetained mergeShape;
	    GeometryRetained firstGeo;
	    int num = 0;
	    int compileFlags = 0;

	    while (listIterator.hasNext()) {
			Vector<Shape3DRetained> curList = listIterator.next();
		int numShapes = curList.size();
		Shape3DRetained[] shapes = new Shape3DRetained[numShapes];
		curList.copyInto(shapes);
		Shape3DRetained[] toBeMergedShapes = new Shape3DRetained[numShapes];
		for (int i = 0; i < numShapes; i++) {
		    if (shapes[i] == null) {
			continue;
		    }
		    firstGeo = null;
		    num = 0;
		    // Get the first non-null geometry
		    while (firstGeo == null && num < shapes[i].geometryList.size()) {
					firstGeo = shapes[i].geometryList.get(num);
			num++;
		    }

		    if (firstGeo != null && firstGeo instanceof GeometryArrayRetained) {
			int numMerge = 0;
			mergeShape = shapes[i];
			GeometryArrayRetained mergeGeo = (GeometryArrayRetained)firstGeo;

			toBeMergedShapes[numMerge++] = mergeShape;
			// Determine if all mergeable shapes have the same boundsCompute
			// and collisionBounds set the same way
			compileFlags = getCompileFlags(mergeShape);
			for (int j = i+1; j < numShapes; j++) {
			    if (shapes[j] == null) {
				continue;
			    }
			    firstGeo = null;
			    num = 0;
			    // Get the first non-null geometry
			    while (firstGeo == null && num < shapes[j].geometryList.size()) {
							firstGeo = shapes[j].geometryList.get(num);
				num++;
			    }

			    // There is a non-null geometry for this shape ..
			    if (firstGeo != null &&
				shapes[j].isEquivalent(mergeShape) &&
				firstGeo.isEquivalenceClass(mergeGeo) &&
				((GeometryArrayRetained)firstGeo).vertexFormat == mergeGeo.vertexFormat) {
				    // got one to merge, add shapes to merge,
				    toBeMergedShapes[numMerge++] = shapes[j];

				    compileFlags |= getCompileFlags(shapes[j]);

				    // remove from shapes
				    shapes[j] = null;
			    }
			}
			if (numMerge > 1) {

			    // remove the shapes from its parent before merge
			    // They all should
			    GroupRetained group = (GroupRetained)toBeMergedShapes[0].parent;
			    Shape3DRetained s;
			    for (int n = 0; n < numMerge; n++) {
				s = toBeMergedShapes[n];
				boolean found = false;
				int numChilds = group.numChildren();
				for (int k = 0; (k < numChilds && !found); k++) {
				    if (group.getChild(k).retained == s) {
					found = true;
					group.removeChild(k);
				    }
				}
				if (!found) {
				    System.err.println("ShapeSet.add(): Can't remove " +
						       "shape from parent, can't find shape!");
				}

			    }

			    mergeShape = new Shape3DCompileRetained(toBeMergedShapes, numMerge, compileFlags);

			    if (J3dDebug.devPhase && J3dDebug.debug) {
				if (J3dDebug.doDebug(J3dDebug.compileState, J3dDebug.LEVEL_3)) {
				    System.err.println("Dest is "+ parentGroup);
				    System.err.println("Compile Shape "+mergeShape);
				    System.err.println(mergeShape.geometryList.size()+" geoemtryList");
								for (int j = 0; j < mergeShape.geometryList.size(); j++) {
									GeometryRetained geo = mergeShape.geometryList.get(j);
									if (geo != null)
										System.err.println("\t Geo_type = " + geo.geoType);
								}

				    System.err.println(numMerge+" Shapes were merged ");
				    for (int j = 0; j < numMerge; j++) {
					System.err.println("\t" + toBeMergedShapes[j]);
				    }
				}
			    }

			    // Set the source to one of the merged shape's source
			    mergeShape.setSource(toBeMergedShapes[0].source);
			    numMergeSets++;
			    numMergeShapes += numMerge ;
			    parentGroup.addChild((Node)mergeShape.source);
			}
		    }
		    // add the shape to the dest
		}
	    }
	}

	// Clear the shapelists for the next merge
	shapeLists.clear();

    }


    int getCompileFlags(Shape3DRetained shape) {
	int cflag = 0;

	// If allow intersect is turned on , then geometry is readable
	if (shape.allowIntersect() ||
	    shape.source.getCapability(Shape3D.ALLOW_GEOMETRY_READ)||
	    (shape.boundsAutoCompute &&
	     shape.source.getCapability(Shape3D.ALLOW_BOUNDS_READ)))
	    cflag |= GEOMETRY_READ;

	return cflag;

    }

}