package org.spring4gwt.examples.simplerpc.server.servlet;

import java.lang.reflect.Method;
import java.util.concurrent.Callable;

import javax.servlet.http.HttpServletRequest;

import org.springframework.beans.BeansException;
import org.springframework.context.ApplicationContext;
import org.springframework.context.ApplicationContextAware;
import org.springframework.web.context.support.WebApplicationContextUtils;

import com.google.web.bindery.requestfactory.server.RequestFactoryServlet;
import com.google.web.bindery.requestfactory.server.ServiceLayerDecorator;
import com.google.web.bindery.requestfactory.shared.Locator;

public class GWTSpringServiceLayerDecorator extends ServiceLayerDecorator
		implements ApplicationContextAware {
	private ApplicationContext context;

	@Override
	public <T extends Locator<?, ?>> T createLocator(Class<T> clazz) {

		HttpServletRequest request = RequestFactoryServlet
				.getThreadLocalRequest();
		ApplicationContext context = WebApplicationContextUtils
				.getWebApplicationContext(request.getSession()
						.getServletContext());

		return context.getBean(clazz);
	}

	@Override
	public void setApplicationContext(ApplicationContext arg0)
			throws BeansException {
		// TODO Auto-generated method stub
		this.context = arg0;
	}
	
	@Override
	public Object invoke(Method domainMethod, Object... args) {
		Object response = super.invoke(domainMethod, args);
		try {
			if (response instanceof Callable) {
				return ((Callable<?>) response).call();
			} else {
				return response;
			}
		} catch (Exception e) {
			throw new RuntimeException(e);
		}
	}

}