/*******************************************************************************
 * Copyright 2014 Federal Chancellery Austria
 * MOA-ID has been developed in a cooperation between BRZ, the Federal
 * Chancellery Austria - ICT staff unit, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.1 or - as soon they will be approved by
 * the European Commission - subsequent versions of the EUPL (the "Licence");
 * You may not use this work except in compliance with the Licence.
 * You may obtain a copy of the Licence at:
 * http://www.osor.eu/eupl/
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the Licence is distributed on an "AS IS" basis,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the Licence for the specific language governing permissions and
 * limitations under the Licence.
 *
 * This product combines work with different licenses. See the "NOTICE" text
 * file for details on the various modules and licenses.
 * The "NOTICE" text file is part of the distribution. Any derivative works
 * that you distribute must include a readable copy of the "NOTICE" text file.
 *******************************************************************************/
package at.gv.egovernment.moa.id.protocols.saml1;

import java.util.HashMap;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.lang.StringEscapeUtils;

import at.gv.egovernment.moa.id.auth.MOAIDAuthConstants;
import at.gv.egovernment.moa.id.auth.exception.AuthenticationException;
import at.gv.egovernment.moa.id.auth.exception.MOAIDException;
import at.gv.egovernment.moa.id.auth.exception.ProtocolNotActiveException;
import at.gv.egovernment.moa.id.auth.exception.WrongParametersException;
import at.gv.egovernment.moa.id.auth.servlet.RedirectServlet;
import at.gv.egovernment.moa.id.commons.db.dao.config.OASAML1;
import at.gv.egovernment.moa.id.config.auth.AuthConfigurationProvider;
import at.gv.egovernment.moa.id.config.auth.OAAuthParameter;
import at.gv.egovernment.moa.id.moduls.IAction;
import at.gv.egovernment.moa.id.moduls.IModulInfo;
import at.gv.egovernment.moa.id.moduls.IRequest;
import at.gv.egovernment.moa.id.moduls.RequestImpl;
import at.gv.egovernment.moa.id.util.ParamValidatorUtils;
import at.gv.egovernment.moa.logging.Logger;
import at.gv.egovernment.moa.util.URLEncoder;

public class SAML1Protocol implements IModulInfo, MOAIDAuthConstants {

	public static final String NAME = SAML1Protocol.class.getName();
	public static final String PATH = "id_saml1";

	public static final String GETARTIFACT = "GetArtifact";

	private static HashMap<String, IAction> actions = new HashMap<String, IAction>();
	
	static {

		actions.put(GETARTIFACT, new GetArtifactAction());
		
		instance = new SAML1Protocol();
	}

	private static SAML1Protocol instance = null;

	public static SAML1Protocol getInstance() {
		if (instance == null) {
			instance = new SAML1Protocol();
		}
		return instance;
	}

	public String getName() {
		return NAME;
	}

	public String getPath() {
		return PATH;
	}

	public IRequest preProcess(HttpServletRequest request,
			HttpServletResponse response, String action) throws MOAIDException {
		RequestImpl config = new RequestImpl();
		
		if (!AuthConfigurationProvider.getInstance().getAllowedProtocols().isSAML1Active()) {
			Logger.info("SAML1 is deaktivated!");
			throw new ProtocolNotActiveException("auth.22", new Object[] { NAME });
			
		}
			
		String oaURL = (String) request.getParameter(PARAM_OA);
		//oaURL = StringEscapeUtils.escapeHtml(oaURL);
		
		String target = (String) request.getParameter(PARAM_TARGET);
		target = StringEscapeUtils.escapeHtml(target);
		
		//the target parameter is used to define the OA in SAML1 standard
		if (target != null && target.startsWith("http")) {
			oaURL = target;
			target = null;
		}
		
		if (!ParamValidatorUtils.isValidOA(oaURL))
			throw new WrongParametersException("StartAuthentication", PARAM_OA,
					"auth.12");
		config.setOAURL(oaURL);
		
		Logger.info("Dispatch SAML1 Request: OAURL=" + oaURL);
		
		//load Target only from OA config
		OAAuthParameter oaParam = AuthConfigurationProvider.getInstance()
				.getOnlineApplicationParameter(oaURL);
		
		if (oaParam == null)
			throw new AuthenticationException("auth.00",
					new Object[] { oaURL });
				
		OASAML1 saml1 = oaParam.getSAML1Parameter();
		if (saml1 == null || !(saml1.isIsActive() != null && saml1.isIsActive()) ) {
			Logger.info("Online-Application " + oaURL + " can not use SAML1 for authentication.");
			throw new AuthenticationException("auth.00",
					new Object[] { oaURL });
		}
		
		config.setTarget(oaParam.getTarget());
		
		request.getSession().setAttribute(PARAM_OA, oaURL);
		request.getSession().setAttribute(PARAM_TARGET, oaParam.getTarget());
		return config;
	}

	public boolean generateErrorMessage(Throwable e,
			HttpServletRequest request, HttpServletResponse response,
			IRequest protocolRequest) 
					throws Throwable{
		
		SAML1AuthenticationServer saml1authentication = SAML1AuthenticationServer.getInstace();
		
		String samlArtifactBase64 = saml1authentication.BuildErrorAssertion(e, protocolRequest);
		
		String url = "RedirectServlet";
		url = addURLParameter(url, RedirectServlet.REDIRCT_PARAM_URL, URLEncoder.encode(protocolRequest.getOAURL(), "UTF-8"));
		url = addURLParameter(url, PARAM_SAMLARTIFACT, URLEncoder.encode(samlArtifactBase64, "UTF-8"));
		url = response.encodeRedirectURL(url);
		
		response.setContentType("text/html");
		response.setStatus(302);
		response.addHeader("Location", url);
		Logger.debug("REDIRECT TO: " + url);
		
		return true;
	}

	public IAction getAction(String action) {
		return actions.get(action);
	}

	public IAction canHandleRequest(HttpServletRequest request,
			HttpServletResponse response) {
		return null;
	}

	public boolean validate(HttpServletRequest request,
			HttpServletResponse response, IRequest pending) {
		
		return true;
	}
	
	protected static String addURLParameter(String url, String paramname,
			String paramvalue) {
		String param = paramname + "=" + paramvalue;
		if (url.indexOf("?") < 0)
			return url + "?" + param;
		else
			return url + "&" + param;
	}

}