/*******************************************************************************
 * Copyright (c) 2007, 2010 Association for Decentralized Information Management
 * in Industry THTH ry.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     VTT Technical Research Centre of Finland - initial API and implementation
 *******************************************************************************/
package org.simantics.g2d.element.handler.impl;

import java.awt.geom.AffineTransform;
import java.awt.geom.Point2D;
import java.util.Collection;

import org.simantics.g2d.canvas.ICanvasContext;
import org.simantics.g2d.diagram.IDiagram;
import org.simantics.g2d.element.ElementHints;
import org.simantics.g2d.element.IElement;
import org.simantics.g2d.element.handler.LifeCycle;
import org.simantics.g2d.element.handler.Move;
import org.simantics.g2d.element.handler.Rotate;
import org.simantics.g2d.element.handler.Scale;
import org.simantics.g2d.element.handler.Transform;
import org.simantics.g2d.element.handler.Validator;

/**
 * This class implements Transform, Move, Rotate, and Scale.
 * It maintains element position in element variable ElementHints.KEY_TRANSFORM.
 * 
 * @author Toni Kalajainen
 */
public class DefaultTransform implements Transform, Move, Rotate, Scale, Validator, LifeCycle {

    private static final long serialVersionUID = -2394690413166528179L;

    public static final DefaultTransform INSTANCE = new DefaultTransform(null);

    Double aspectRatio;

    public DefaultTransform() {
        this(null);
    }

    public DefaultTransform(Double aspectRatio) {
        this.aspectRatio = aspectRatio;
    }

    @Override
    public Double getFixedAspectRatio(IElement e) {
        return aspectRatio;
    }

    @Override
    public Point2D getScale(IElement e) {
        AffineTransform at = e.getHint(ElementHints.KEY_TRANSFORM);
        return _getScale(at);
    }

    @Override
    public void setScale(IElement e, Point2D newScale) {
        Point2D oldScale = getScale(e);
        double sx = newScale.getX() / oldScale.getX();
        double sy = newScale.getY() / oldScale.getY();
        AffineTransform at = e.getHint(ElementHints.KEY_TRANSFORM);
        at = new AffineTransform(at);
        at.scale(sx, sy);
        e.setHint(ElementHints.KEY_TRANSFORM, at);
    }

    @Override
    public Point2D getMaximumScale(IElement e) {
        return null;
    }

    @Override
    public Point2D getMinimumScale(IElement e) {
        return null;
    }

    private static Point2D _getScale(AffineTransform at) {
        double m00 = at.getScaleX();
        double m11 = at.getScaleY();
        double m10 = at.getShearY();
        double m01 = at.getShearX();
        // Project unit vector to canvas
        double sx = Math.sqrt(m00 * m00 + m10 * m10);
        double sy = Math.sqrt(m01 * m01 + m11 * m11);
        return new Point2D.Double(sx, sy);
    }

    @Override
    public void validate(final IElement e, final ICanvasContext ctx, Collection<Issue> lst) {
        /*
		if (aspectRatio != null) {
			// Validate aspect ratio
			final Point2D scale = getScale(e);
			double currentRatio = scale.getX() / scale.getY();
			if (Math.abs(currentRatio - aspectRatio) > 0.000001) {
				lst.add(new Issue() {
					@Override
					public String getMessage() {
						return "Aspect ratio is wrong";
					}

					@Override
					public void addSuggestions(
							Collection<Suggestion> suggestionList) {
						suggestionList.add(new Suggestion() {
							@Override
							public boolean fix() {
								double newSx = scale.getX();
								double newSy = newSx * aspectRatio;
								Point2D newScale = new Point2D.Double(newSx,
										newSy);
								setScale(e, newScale);
								ctx.setDirty();
								return true;
							}

							@Override
							public String getMessage() {
								return "Scale height, keep width";
							}
						});
					}
				});
			}
			// TODO min scale validator
			// TODO max scale validator
		}

		if (e.getHint(ElementHints.KEY_TRANSFORM) == null) {
			Issue i = new Issue() {
				@Override
				public String getMessage() {
					return "Transform is missing";
				}

				@Override
				public void addSuggestions(Collection<Suggestion> suggestionList) {
					Suggestion s = new Suggestion() {
						@Override
						public boolean fix() {
							e.setHint(ElementHints.KEY_TRANSFORM,
									new AffineTransform());
							return true;
						}

						@Override
						public String getMessage() {
							return "Set default transform";
						}
					};
					suggestionList.add(s);
				}
			};
			lst.add(i);
		}
         */
    }

    @Override
    public void rotate(IElement e, double theta, Point2D origo) {
        if (Double.isNaN(theta)) return;
        AffineTransform at = e.getHint(ElementHints.KEY_TRANSFORM);
        at = (AffineTransform) at.clone();
        Point2D localOrigo = at.transform(origo, null);
        at.preConcatenate(AffineTransform.getRotateInstance(theta, localOrigo.getX(), localOrigo.getY()));
        // This code concatenated the matrix from the wrong side
        //at.rotate(theta, origo.getX(), origo.getY());
        e.setHint(ElementHints.KEY_TRANSFORM, at);
    }

    @Override
    public double getAngle(IElement e) {
        AffineTransform at = e.getHint(ElementHints.KEY_TRANSFORM);
        double m01 = at.getShearX();
        double m11 = at.getScaleY();
        return -Math.atan2(m01, m11);
    }

    @Override
    public Point2D getPosition(IElement e) {
        AffineTransform at = e.getHint(ElementHints.KEY_TRANSFORM);
        Point2D p = new Point2D.Double(at.getTranslateX(), at.getTranslateY());
        return p;
    }

    @Override
    public void moveTo(IElement e, double x, double y) {
        AffineTransform origAt = e.getHint(ElementHints.KEY_TRANSFORM);

        AffineTransform result = new AffineTransform(origAt);
        result.preConcatenate(AffineTransform.getTranslateInstance(x - origAt.getTranslateX(), y - origAt.getTranslateY()));
        e.setHint(ElementHints.KEY_TRANSFORM, result);
    }

    @Override
    public AffineTransform getTransform(IElement e) {

        AffineTransform at = e.getHint(ElementHints.KEY_TRANSFORM);

        IElement parentElement = e.getHint(ElementHints.KEY_PARENT_ELEMENT);
        if(parentElement == null) return at;

        Transform parentTransform = parentElement.getElementClass().getSingleItem(Transform.class);
        assert(parentTransform!=null);

        AffineTransform result = (AffineTransform)at.clone();
        AffineTransform parentAT = parentTransform.getTransform(parentElement);
        result.preConcatenate(AffineTransform.getTranslateInstance(parentAT.getTranslateX(), parentAT.getTranslateY()));

        return result;

    }

    @Override
    public void setTransform(IElement e, AffineTransform at) {
        e.setHint(ElementHints.KEY_TRANSFORM, at.clone());
    }

    @Override
    public void onElementActivated(IDiagram d, IElement e) {
    }

    @Override
    public void onElementCreated(IElement e) {
        e.setHint(ElementHints.KEY_TRANSFORM, new AffineTransform());
    }

    @Override
    public void onElementDeactivated(IDiagram d, IElement e) {
    }

    @Override
    public void onElementDestroyed(IElement e) {
    }


}