/*
 * Copyright (c) 2012 Diamond Light Source Ltd.
 *
 * 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
 */

package uk.ac.diamond.scisoft.analysis.rpc;

import java.lang.reflect.Method;
import java.lang.reflect.Modifier;

/**
 * Concrete class that filters on instance methods and delegates to the instance provided.
 */
public class AnalysisRpcGenericInstanceDispatcher extends AbstractAnalysisRpcGenericDispatcher {
	private final Object instance;

	/**
	 * Create a new dispatcher
	 * 
	 * @param delegate
	 *            the type of class to delegate to. By providing an interface class here a limited view on the public
	 *            methods provided by instance will be exposed
	 * @param instance
	 *            instance of the class to delegate to
	 * @throws NullPointerException
	 *             if delegate or instance is <code>null</code>
	 * @throws IllegalArgumentException
	 *             if instance is not an instance of delegate
	 */
	public AnalysisRpcGenericInstanceDispatcher(Class<?> delegate, Object instance) {
		super(delegate);
		if (instance == null)
			throw new NullPointerException("Instance must be non-null");
		if (!delegate.isInstance(instance))
			throw new IllegalArgumentException("Instance must be an instance of class represented by delegate");
		this.instance = instance;
	}

	/**
	 * Create a new dispatcher
	 * 
	 * @param instance
	 *            instance of the class to delegate to, the type of the delgating class is based on the instance
	 * @throws NullPointerException
	 *             if instance is <code>null</code>
	 */
	public static AnalysisRpcGenericInstanceDispatcher getDispatcher(Object instance) {
		return new AnalysisRpcGenericInstanceDispatcher(instance.getClass(), instance);
	}

	/**
	 * Filter out static methods
	 */
	@Override
	protected boolean isMethodOk(Method method, String dispatchMethodName, Class<?>[] dispatchArgTypes) {
		if (Modifier.isStatic(method.getModifiers())) {
			return false;
		}

		return super.isMethodOk(method, dispatchMethodName, dispatchArgTypes);
	}


	/**
	 * Return the instance to dispatch to
	 */
	@Override
	protected Object getInvokeObject() {
		return instance;
	}
}