/*******************************************************************************
 * ============LICENSE_START====================================================
 * * org.onap.aaf
 * * ===========================================================================
 * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
 * * ===========================================================================
 * * Licensed under the Apache License, Version 2.0 (the "License");
 * * you may not use this file except in compliance with the License.
 * * You may obtain a copy of the License at
 * * 
 *  *      http://www.apache.org/licenses/LICENSE-2.0
 * * 
 *  * Unless required by applicable law or agreed to in writing, software
 * * distributed under the License is distributed on an "AS IS" BASIS,
 * * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * * See the License for the specific language governing permissions and
 * * limitations under the License.
 * * ============LICENSE_END====================================================
 * *
 * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
 * *
 ******************************************************************************/
package com.att.cadi.filter;

import java.io.IOException;

import javax.servlet.Servlet;
import javax.servlet.ServletConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 * 
 *
 */
public class AUTHZServlet<S extends Servlet> implements Servlet {
	private String[] roles;
	private Servlet delegate;

	protected AUTHZServlet(Class<S> cls) {
		try {
			delegate = cls.newInstance();
		} catch (Exception e) {
			delegate = null;
		}
		RolesAllowed rolesAllowed = cls.getAnnotation(RolesAllowed.class);
		if(rolesAllowed == null) {
			roles = null;
		} else {
			roles = rolesAllowed.value();
		}
	}
	
	public void init(ServletConfig sc) throws ServletException {
		if(delegate == null) throw new ServletException("Invalid Servlet Delegate");
		delegate.init(sc);
	}
	
	public ServletConfig getServletConfig() {
		return delegate.getServletConfig();
	}

	public String getServletInfo() {
		return delegate.getServletInfo();
	}

	public void service(ServletRequest req, ServletResponse resp) throws ServletException, IOException {
		if(roles==null) {
			delegate.service(req,resp);
		} else { // Validate
			try {
				HttpServletRequest hreq = (HttpServletRequest)req;
				boolean proceed = false;
				for(String role : roles) {
					if(hreq.isUserInRole(role)) {
						proceed = true;
						break;
					}
				}
				if(proceed) {
					delegate.service(req,resp);
				} else {
					//baseRequest.getServletContext().log(hreq.getUserPrincipal().getName()+" Refused " + roles);
					((HttpServletResponse)resp).sendError(403); // forbidden
				}
			} catch(ClassCastException e) {
				throw new ServletException("JASPIServlet only supports HTTPServletRequest/HttpServletResponse");
			}
		}
	}

	public void destroy() {
		delegate.destroy();
	}


}