/*******************************************************************************
 * 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.message;


/**
 * Example usage:
 * <pre>
 * public class MyResourceSchemeHandler extends AbstractMessageSchemeHandler<MyResource> {
 *     public MyResourceSchemeHandler() {
 *         super("myresource", MyResource.class);
 *     }
 *     public void doPerform(MyResource r) {
 *         // Do your stuff...
 *     }
 * }
 * </pre>
 * 
 * @author Tuukka Lehtonen
 */
public abstract class AbstractMessageSchemeHandler<T> implements IMessageSchemeHandler {

    private String scheme;
    private Class<?> expectedDataClass;
    
    public AbstractMessageSchemeHandler(String scheme, Class<?> expectedDataClass) {
        this.scheme = scheme;
        this.expectedDataClass = expectedDataClass;
    }
    
    @Override
    public String getScheme() {
        return scheme;
    }

    @SuppressWarnings("unchecked")
    @Override
    public void perform(Object o) throws MessageSchemeException {
        if (expectedDataClass.isInstance(o)) {
            doPerform((T) o);
        } else {
            handleInvalidData(o);
        }
    }

    public void handleInvalidData(Object o) {
        // Override to handle differently
        throw new RuntimeException("Object " + o + " is not an instance of " + expectedDataClass.getCanonicalName());
    }

    public abstract void doPerform(T o) throws MessageSchemeException;

}