/*******************************************************************************
 * Copyright (c) 2007, 2013 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
 *     Semantum Oy - issue #4214
 *******************************************************************************/
package org.simantics.ui.icons;

import java.io.ByteArrayInputStream;
import java.util.Arrays;

import org.eclipse.jface.resource.ImageDescriptor;
import org.eclipse.swt.SWT;
import org.eclipse.swt.SWTException;
import org.eclipse.swt.graphics.ImageData;
import org.eclipse.swt.graphics.ImageLoader;
import org.simantics.databoard.Bindings;
import org.simantics.db.ReadGraph;
import org.simantics.db.RequestProcessor;
import org.simantics.db.Resource;
import org.simantics.db.common.primitiverequest.PossibleValue;
import org.simantics.db.exception.DatabaseException;

/**
 * @author Hannu Niemistö
 * @author Tuukka Lehtonen
 */
public class GraphImageDescriptor extends ImageDescriptor {

	private Resource resource;
    private long resourceId;
    private byte[] data;
    private int hash;

    public GraphImageDescriptor(ReadGraph graph, Resource resource) throws DatabaseException {
        this.resource = resource;
        this.resourceId = resource.getResourceId();
        this.data = getImageDataBytes(graph);
        this.hash = (Arrays.hashCode(this.data) * 31 + (int)(resourceId>>>32)) * 31 + ((int)resourceId);
    }

    private byte[] getImageDataBytes(RequestProcessor processor) throws DatabaseException {
        return processor.syncRequest(new PossibleValue<byte[]>(resource, Bindings.BYTE_ARRAY));
    }

    private ImageData toImageData(byte[] data) throws SWTException {
        ImageData[] images = new ImageLoader().load(new ByteArrayInputStream(data));
        if (images.length == 0)
            SWT.error(SWT.ERROR_INVALID_IMAGE, null, "No images found in image data of resource $" + resourceId);
        return images[0];
    }

    @Override
    public ImageData getImageData() {
        try {
            ImageData imageData = toImageData(data);
            return imageData;
        } catch (SWTException e) {
            return null;
        }
    }
    
    public Resource getResource() {
    	return resource;
    }

    @Override
    public String toString() {
        return super.toString() + "[" + resource + "]";
    }

    @Override
    public int hashCode() {
        return hash;
    }

    @Override
    public boolean equals(Object obj) {
        if (this == obj)
            return true;
        if (obj == null)
            return false;
        if (getClass() != obj.getClass())
            return false;
        GraphImageDescriptor other = (GraphImageDescriptor) obj;
        if (!resource.equals(other.resource))
            return false;
        if (!Arrays.equals(data, other.data))
            return false;
        return true;
    }

}