/*
 * Copyright (c) 2009-2010 jMonkeyEngine
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * * Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * * Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * * Neither the name of 'jMonkeyEngine' nor the names of its contributors
 *   may be used to endorse or promote products derived from this software
 *   without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
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 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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package com.jme3.scene.plugins.blender.objects;

import java.util.Collection;
import java.util.List;
import java.util.logging.Level;
import java.util.logging.Logger;

import com.jme3.asset.BlenderKey.FeaturesToLoad;
import com.jme3.light.DirectionalLight;
import com.jme3.light.Light;
import com.jme3.light.PointLight;
import com.jme3.light.SpotLight;
import com.jme3.math.Matrix4f;
import com.jme3.math.Quaternion;
import com.jme3.math.Transform;
import com.jme3.math.Vector3f;
import com.jme3.renderer.Camera;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import com.jme3.scene.Spatial;
import com.jme3.scene.Spatial.CullHint;
import com.jme3.scene.plugins.blender.AbstractBlenderHelper;
import com.jme3.scene.plugins.blender.BlenderContext;
import com.jme3.scene.plugins.blender.BlenderContext.LoadedFeatureDataType;
import com.jme3.scene.plugins.blender.cameras.CameraHelper;
import com.jme3.scene.plugins.blender.constraints.Constraint;
import com.jme3.scene.plugins.blender.constraints.ConstraintHelper;
import com.jme3.scene.plugins.blender.curves.CurvesHelper;
import com.jme3.scene.plugins.blender.exceptions.BlenderFileException;
import com.jme3.scene.plugins.blender.file.DynamicArray;
import com.jme3.scene.plugins.blender.file.Pointer;
import com.jme3.scene.plugins.blender.file.Structure;
import com.jme3.scene.plugins.blender.lights.LightHelper;
import com.jme3.scene.plugins.blender.meshes.MeshHelper;
import com.jme3.scene.plugins.blender.modifiers.Modifier;
import com.jme3.scene.plugins.blender.modifiers.ModifierHelper;

/**
 * A class that is used in object calculations.
 * @author Marcin Roguski (Kaelthas)
 */
public class ObjectHelper extends AbstractBlenderHelper {
	private static final Logger			LOGGER		= Logger.getLogger(ObjectHelper.class.getName());

	protected static final int		OBJECT_TYPE_EMPTY			= 0;
	protected static final int		OBJECT_TYPE_MESH			= 1;
	protected static final int		OBJECT_TYPE_CURVE			= 2;
	protected static final int		OBJECT_TYPE_SURF			= 3;
	protected static final int		OBJECT_TYPE_TEXT			= 4;
	protected static final int		OBJECT_TYPE_METABALL		= 5;
	protected static final int		OBJECT_TYPE_LAMP			= 10;
	protected static final int		OBJECT_TYPE_CAMERA			= 11;
	protected static final int		OBJECT_TYPE_WAVE			= 21;
	protected static final int		OBJECT_TYPE_LATTICE			= 22;
	protected static final int		OBJECT_TYPE_ARMATURE		= 25;
	
	/**
	 * This constructor parses the given blender version and stores the result. Some functionalities may differ in
	 * different blender versions.
	 * @param blenderVersion
	 *        the version read from the blend file
	 * @param fixUpAxis
     *        a variable that indicates if the Y asxis is the UP axis or not
	 */
	public ObjectHelper(String blenderVersion, boolean fixUpAxis) {
		super(blenderVersion, fixUpAxis);
	}

	/**
	 * This method reads the given structure and createn an object that represents the data.
	 * @param objectStructure
	 *            the object's structure
	 * @param blenderContext
	 *            the blender context
	 * @return blener's object representation
	 * @throws BlenderFileException
	 *             an exception is thrown when the given data is inapropriate
	 */
	public Object toObject(Structure objectStructure, BlenderContext blenderContext) throws BlenderFileException {
		Object loadedResult = blenderContext.getLoadedFeature(objectStructure.getOldMemoryAddress(), LoadedFeatureDataType.LOADED_FEATURE);
		if(loadedResult != null) {
			return loadedResult;
		}

		blenderContext.pushParent(objectStructure);

		//get object data
		int type = ((Number)objectStructure.getFieldValue("type")).intValue();
		String name = objectStructure.getName();
		LOGGER.log(Level.INFO, "Loading obejct: {0}", name);

		int restrictflag = ((Number)objectStructure.getFieldValue("restrictflag")).intValue();
		boolean visible = (restrictflag & 0x01) != 0;
		Object result = null;

		Pointer pParent = (Pointer)objectStructure.getFieldValue("parent");
		Object parent = blenderContext.getLoadedFeature(pParent.getOldMemoryAddress(), LoadedFeatureDataType.LOADED_FEATURE);
		if(parent == null && pParent.isNotNull()) {
			Structure parentStructure = pParent.fetchData(blenderContext.getInputStream()).get(0);
			parent = this.toObject(parentStructure, blenderContext);
		}

		Transform t = this.getTransformation(objectStructure, blenderContext);
		
		try {
			switch(type) {
				case OBJECT_TYPE_EMPTY:
					LOGGER.log(Level.INFO, "Importing empty.");
					Node empty = new Node(name);
					empty.setLocalTransform(t);
					if(parent instanceof Node) {
						((Node) parent).attachChild(empty);
					}
					empty.updateModelBound();
					result = empty;
					break;
				case OBJECT_TYPE_MESH:
					LOGGER.log(Level.INFO, "Importing mesh.");
					Node node = new Node(name);
					node.setCullHint(visible ? CullHint.Always : CullHint.Inherit);

					//reading mesh
					MeshHelper meshHelper = blenderContext.getHelper(MeshHelper.class);
					Pointer pMesh = (Pointer)objectStructure.getFieldValue("data");
					List<Structure> meshesArray = pMesh.fetchData(blenderContext.getInputStream());
					List<Geometry> geometries = meshHelper.toMesh(meshesArray.get(0), blenderContext);
					if (geometries != null){
                        for(Geometry geometry : geometries) {
                            node.attachChild(geometry);
                        }
                    }
					node.setLocalTransform(t);

					//reading and applying all modifiers
					ModifierHelper modifierHelper = blenderContext.getHelper(ModifierHelper.class);
					Collection<Modifier> modifiers = modifierHelper.readModifiers(objectStructure, blenderContext);
					for(Modifier modifier : modifiers) {
						modifier.apply(node, blenderContext);
					}

					//setting the parent
					if(parent instanceof Node) {
						((Node)parent).attachChild(node);
					}
					node.updateModelBound();//I prefer do calculate bounding box here than read it from the file
					result = node;
					break;
				case OBJECT_TYPE_SURF:
				case OBJECT_TYPE_CURVE:
					LOGGER.log(Level.INFO, "Importing curve/nurb.");
					Pointer pCurve = (Pointer)objectStructure.getFieldValue("data");
					if(pCurve.isNotNull()) {
						CurvesHelper curvesHelper = blenderContext.getHelper(CurvesHelper.class);
						Structure curveData = pCurve.fetchData(blenderContext.getInputStream()).get(0);
						List<Geometry> curves = curvesHelper.toCurve(curveData, blenderContext);
						result = new Node(name);
						for(Geometry curve : curves) {
							((Node)result).attachChild(curve);
						}
						((Node)result).setLocalTransform(t);
					}
					break;
				case OBJECT_TYPE_LAMP:
					LOGGER.log(Level.INFO, "Importing lamp.");
					Pointer pLamp = (Pointer)objectStructure.getFieldValue("data");
					if(pLamp.isNotNull()) {
						LightHelper lightHelper = blenderContext.getHelper(LightHelper.class);
						List<Structure> lampsArray = pLamp.fetchData(blenderContext.getInputStream());
						Light light = lightHelper.toLight(lampsArray.get(0), blenderContext);
						if(light!=null) {
							light.setName(name);
						}
						if(light instanceof PointLight) {
							((PointLight)light).setPosition(t.getTranslation());
						} else if(light instanceof DirectionalLight) {
							Quaternion quaternion = t.getRotation();
							Vector3f[] axes = new Vector3f[3];
							quaternion.toAxes(axes);
							if(fixUpAxis) {
								((DirectionalLight)light).setDirection(axes[1].negate());//-Z is the direction axis of area lamp in blender
							} else {
								((DirectionalLight)light).setDirection(axes[2].negate());
							}
						} else if(light instanceof SpotLight) {
							((SpotLight)light).setPosition(t.getTranslation());
							
							Quaternion quaternion = t.getRotation();
							Vector3f[] axes = new Vector3f[3];
							quaternion.toAxes(axes);
							if(fixUpAxis) {
								((SpotLight)light).setDirection(axes[1].negate());//-Z is the direction axis of area lamp in blender
							} else {
								((SpotLight)light).setDirection(axes[2].negate());
							}
						} else {
							LOGGER.log(Level.WARNING, "Unknown type of light: {0}", light);
						}
						result = light;
					}
					break;
				case OBJECT_TYPE_CAMERA:
					Pointer pCamera = (Pointer)objectStructure.getFieldValue("data");
					if(pCamera.isNotNull()) {
						CameraHelper cameraHelper = blenderContext.getHelper(CameraHelper.class);
						List<Structure> camerasArray = pCamera.fetchData(blenderContext.getInputStream());
						Camera camera = cameraHelper.toCamera(camerasArray.get(0));
						camera.setLocation(t.getTranslation());
						camera.setRotation(t.getRotation());
						result = camera;
					}
					break;
				case OBJECT_TYPE_ARMATURE:
					//need to create an empty node to properly create parent-children relationships between nodes
					Node armature = new Node(name);
					armature.setLocalTransform(t);
					//TODO: modifiers for armature ????
					if(parent instanceof Node) {
						((Node)parent).attachChild(armature);
					}
					armature.updateModelBound();//I prefer do calculate bounding box here than read it from the file
					result = armature;
					break;
				default:
					LOGGER.log(Level.WARNING, "Unknown object type: {0}", type);
			}
		} finally {
			blenderContext.popParent();
		}
		
		if(result != null) {
			blenderContext.addLoadedFeatures(objectStructure.getOldMemoryAddress(), name, objectStructure, result);
			
			//loading constraints connected with this object
			ConstraintHelper constraintHelper = blenderContext.getHelper(ConstraintHelper.class);
			constraintHelper.loadConstraints(objectStructure, blenderContext);
			
			//baking constraints
			List<Constraint> objectConstraints = blenderContext.getConstraints(objectStructure.getOldMemoryAddress());
			if(objectConstraints!=null) {
				for(Constraint objectConstraint : objectConstraints) {
					objectConstraint.bake();
				}
			}
			
			//reading custom properties
			Properties properties = this.loadProperties(objectStructure, blenderContext);
			if(result instanceof Spatial && properties != null && properties.getValue() != null) {
				((Spatial)result).setUserData("properties", properties);
			}
		}
		return result;
	}
	
	/**
	 * This method calculates local transformation for the object. Parentage is taken under consideration.
	 * @param objectStructure
	 *        the object's structure
	 * @return objects transformation relative to its parent
	 */
	@SuppressWarnings("unchecked")
	public Transform getTransformation(Structure objectStructure, BlenderContext blenderContext) {
		//these are transformations in global space
		DynamicArray<Number> loc = (DynamicArray<Number>)objectStructure.getFieldValue("loc");
		DynamicArray<Number> size = (DynamicArray<Number>)objectStructure.getFieldValue("size");
		DynamicArray<Number> rot = (DynamicArray<Number>)objectStructure.getFieldValue("rot");

		//load parent inverse matrix
		Pointer pParent = (Pointer) objectStructure.getFieldValue("parent");
		Matrix4f parentInv = pParent.isNull() ? Matrix4f.IDENTITY : this.getMatrix(objectStructure, "parentinv");
		
		//create the global matrix (without the scale)
		Matrix4f globalMatrix = new Matrix4f();
		globalMatrix.setTranslation(loc.get(0).floatValue(), loc.get(1).floatValue(), loc.get(2).floatValue());
		globalMatrix.setRotationQuaternion(new Quaternion().fromAngles(rot.get(0).floatValue(), rot.get(1).floatValue(), rot.get(2).floatValue()));
		//compute local matrix
		Matrix4f localMatrix = parentInv.mult(globalMatrix);

		Vector3f translation = localMatrix.toTranslationVector();
		Quaternion rotation = localMatrix.toRotationQuat();
		Vector3f scale = this.getScale(parentInv).multLocal(size.get(0).floatValue(), size.get(1).floatValue(), size.get(2).floatValue());
		
		if(fixUpAxis) {
			float y = translation.y;
			translation.y = translation.z;
			translation.z = -y;
			
			y = rotation.getY();
			float z = rotation.getZ();
			rotation.set(rotation.getX(), z, -y, rotation.getW());
			
			y=scale.y;
			scale.y = scale.z;
			scale.z = y;
		}
		
		//create the result
		Transform t = new Transform(translation, rotation);
		t.setScale(scale);
		return t;
	}

	/**
	 * This method returns the matrix of a given name for the given structure.
	 * The matrix is NOT transformed if Y axis is up - the raw data is loaded from the blender file.
	 * @param structure
	 *        the structure with matrix data
	 * @param matrixName
	 * 		  the name of the matrix
	 * @return the required matrix
	 */
	public Matrix4f getMatrix(Structure structure, String matrixName) {
		return this.getMatrix(structure, matrixName, false);
	}
	
	/**
	 * This method returns the matrix of a given name for the given structure.
	 * It takes up axis into consideration.
	 * @param structure
	 *        the structure with matrix data
	 * @param matrixName
	 * 		  the name of the matrix
	 * @return the required matrix
	 */
	@SuppressWarnings("unchecked")
	public Matrix4f getMatrix(Structure structure, String matrixName, boolean applyFixUpAxis) {
		Matrix4f result = new Matrix4f();
		DynamicArray<Number> obmat = (DynamicArray<Number>)structure.getFieldValue(matrixName);
		int rowAndColumnSize = Math.abs((int)Math.sqrt(obmat.getTotalSize()));//the matrix must be square
		for(int i = 0; i < rowAndColumnSize; ++i) {
			for(int j = 0; j < rowAndColumnSize; ++j) {
				result.set(i, j, obmat.get(j, i).floatValue());
			}
		}
		if(applyFixUpAxis && fixUpAxis) {
        	Vector3f translation = result.toTranslationVector();
            Quaternion rotation = result.toRotationQuat();
            Vector3f scale = this.getScale(result);
            
			float y = translation.y;
			translation.y = translation.z;
			translation.z = -y;
			
			y = rotation.getY();
			float z = rotation.getZ();
			rotation.set(rotation.getX(), z, -y, rotation.getW());
			
			y=scale.y;
			scale.y = scale.z;
			scale.z = y;
			
			result.loadIdentity();
			result.setTranslation(translation);
			result.setRotationQuaternion(rotation);
			result.setScale(scale);
        }
		return result;
	}

	/**
	 * This method returns the scale from the given matrix.
	 * 
	 * @param matrix
	 *            the transformation matrix
	 * @return the scale from the given matrix
	 */
	public Vector3f getScale(Matrix4f matrix) {
		float scaleX = (float) Math.sqrt(matrix.m00 * matrix.m00 + matrix.m10 * matrix.m10 + matrix.m20 * matrix.m20);
		float scaleY = (float) Math.sqrt(matrix.m01 * matrix.m01 + matrix.m11 * matrix.m11 + matrix.m21 * matrix.m21);
		float scaleZ = (float) Math.sqrt(matrix.m02 * matrix.m02 + matrix.m12 * matrix.m12 + matrix.m22 * matrix.m22);
		return new Vector3f(scaleX, scaleY, scaleZ);
	}
	
	@Override
	public void clearState() {
		fixUpAxis = false;
	}
	
	@Override
	public boolean shouldBeLoaded(Structure structure, BlenderContext blenderContext) {
		int lay = ((Number) structure.getFieldValue("lay")).intValue();
        return ((lay & blenderContext.getBlenderKey().getLayersToLoad()) != 0
                && (blenderContext.getBlenderKey().getFeaturesToLoad() & FeaturesToLoad.OBJECTS) != 0);
	}
}