/*
 * Copyright 2011 the original author or authors.
 *
 * 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.
 */
package org.springframework.security.samples.cas;

import java.io.IOException

import javax.servlet.ServletException
import javax.servlet.http.HttpServletRequest
import javax.servlet.http.HttpServletResponse

import org.apache.commons.httpclient.HttpClient
import org.apache.commons.httpclient.methods.GetMethod;
import org.eclipse.jetty.server.Request
import org.eclipse.jetty.server.Server
import org.eclipse.jetty.server.handler.AbstractHandler
import org.eclipse.jetty.server.ssl.SslSelectChannelConnector
import org.jasig.cas.client.proxy.ProxyGrantingTicketStorage;
import org.jasig.cas.client.proxy.ProxyGrantingTicketStorageImpl;
import org.jasig.cas.client.validation.Assertion
import org.jasig.cas.client.validation.Cas20ProxyTicketValidator;

/**
 * A CAS Service that allows a PGT to be obtained. This is useful for testing use of proxy tickets.
 *
 * @author Rob Winch
 */
class JettyCasService extends Server {
	private Cas20ProxyTicketValidator validator
	private int port = availablePort()

	/**
	 * The Proxy Granting Ticket. To initialize pgt, authenticate to the CAS Server with the service parameter
	 * equal to {@link #serviceUrl()}.
	 */
	String pgt

	/**
	 * Start the CAS Service which will be available at {@link #serviceUrl()}.
	 *
	 * @param casServerUrl
	 * @return
	 */
	def init(String casServerUrl) {
		ProxyGrantingTicketStorage storage = new ProxyGrantingTicketStorageImpl()
		validator = new Cas20ProxyTicketValidator(casServerUrl)
		validator.setAcceptAnyProxy(true)
		validator.setProxyGrantingTicketStorage(storage)
		validator.setProxyCallbackUrl(absoluteUrl('callback'))

		String password = System.getProperty('javax.net.ssl.trustStorePassword','password')
		SslSelectChannelConnector ssl_connector = new SslSelectChannelConnector()
		ssl_connector.setPort(port)
		ssl_connector.setKeystore(getTrustStore())
		ssl_connector.setPassword(password)
		ssl_connector.setKeyPassword(password)
		addConnector(ssl_connector)
		setHandler(new AbstractHandler() {
			public void handle(String target, Request baseRequest,
					HttpServletRequest request, HttpServletResponse response)
			throws IOException, ServletException {
				def st = request.getParameter('ticket')
				if(st) {
					JettyCasService.this.validator.validate(st, JettyCasService.this.serviceUrl())
				}
				def pgt = request.getParameter('pgtId')
				if(pgt) {
				  JettyCasService.this.pgt = pgt
				}
				response.setStatus(HttpServletResponse.SC_OK);
				baseRequest.setHandled(true);
			}
		})
		start()
		this
	}

	/**
	 * Returns the absolute URL that this CAS service is available at.
	 * @return
	 */
	String serviceUrl() {
		absoluteUrl('service')
	}

	/**
	 * Given a relative url, will provide an absolute url for this CAS Service.
	 * @param relativeUrl the relative url (i.e. service, callback, etc)
	 * @return
	 */
	private String absoluteUrl(String relativeUrl) {
		"https://localhost:${port}/${relativeUrl}"
	}

	private static String getTrustStore() {
		String trustStoreLocation = System.getProperty('javax.net.ssl.trustStore')
		if(trustStoreLocation == null || !new File(trustStoreLocation).isFile()) {
			throw new  IllegalStateException('Could not find the trust store at path "'+trustStoreLocation+'". Specify the location using the javax.net.ssl.trustStore system property.')
		}
		trustStoreLocation
	}
	/**
	 * Obtains a random available port (i.e. one that is not in use)
	 * @return
	 */
	private static int availablePort() {
		ServerSocket server = new ServerSocket(0)
		int port = server.localPort
		server.close()
		port
	}
}