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

import java.util.Enumeration;
import java.util.Properties;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.mvc.ServletWrappingController;

public class CustomServletWrappingController extends ServletWrappingController {
	private Class servletClass;
	private String servletName;
	private Properties initParameters = new Properties();
	private String beanName;
	private Servlet servletInstance;
	/**
	 * Set the class of the servlet to wrap. Needs to implement
	 * <code>javax.servlet.Servlet</code>.
	 *
	 * @see javax.servlet.Servlet
	 */
	public void setServletClass(Class servletClass) {
		this.servletClass = servletClass;
	}
	/**
	 * Set the name of the servlet to wrap. Default is the bean name of this
	 * controller.
	 */
	public void setServletName(String servletName) {
		this.servletName = servletName;
	}
	/**
	 * Specify init parameters for the servlet to wrap, as name-value pairs.
	 */
	public void setInitParameters(Properties initParameters) {
		this.initParameters = initParameters;
	}
	public void setBeanName(String name) {
		this.beanName = name;
	}
	/**
	 * Overriden to implement our hack. It initializes the wrapped Servlet
	 * instance.
	 *
	 * @author jatinder-singh
	 * @see javax.servlet.Servlet#init(javax.servlet.ServletConfig)
	 */
	@Override
	public void afterPropertiesSet() throws Exception {
		if (this.servletClass == null) {
			throw new IllegalArgumentException("servletClass is required");
		}
		if (!Servlet.class.isAssignableFrom(this.servletClass)) {
			throw new IllegalArgumentException("servletClass ["
					+ this.servletClass.getName()
					+ "] needs to implement interface [javax.servlet.Servlet]");
		}
		if (this.servletName == null) {
			this.servletName = this.beanName;
		}
		// We retrieve RF instance instead of using the one defined in
		// singhsolution-servlet.xml
		// Author: Jatinder Singh
		this.servletInstance = (Servlet) this.getApplicationContext().getBean(
				"requestFactoryServlet");
		this.servletInstance.init(new DelegatingServletConfig());
	}
	/**
	 * Invoke the the wrapped Servlet instance.
	 *
	 * @see javax.servlet.Servlet#service(javax.servlet.ServletRequest,
	 *      javax.servlet.ServletResponse)
	 */
	@Override
	protected ModelAndView handleRequestInternal(HttpServletRequest request,
			HttpServletResponse response) throws Exception {
		this.servletInstance.service(request, response);
		return null;
	}
	/**
	 * Destroy the wrapped Servlet instance.
	 *
	 * @see javax.servlet.Servlet#destroy()
	 */
	public void destroy() {
		this.servletInstance.destroy();
	}
	/**
	 * Internal implementation of the ServletConfig interface, to be passed to
	 * the wrapped servlet. Delegates to ServletWrappingController fields and
	 * methods to provide init parameters and other environment info.
	 */
	private class DelegatingServletConfig implements ServletConfig {
		public String getServletName() {
			return servletName;
		}
		public ServletContext getServletContext() {
			return CustomServletWrappingController.this.getServletContext();
		}
		public String getInitParameter(String paramName) {
			return initParameters.getProperty(paramName);
		}
		public Enumeration getInitParameterNames() {
			return initParameters.keys();
		}
	}
}