/*
 * Copyright 2011 by Graz University of Technology, Austria
 * The Austrian STORK Modules have been developed by the E-Government
 * Innovation Center EGIZ, a joint initiative of the Federal Chancellery
 * Austria 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 eu.stork.vidp.messages.validation;

import org.opensaml.common.SAMLVersion;
import org.opensaml.saml1.core.StatusCode;
import org.opensaml.saml2.core.Response;
import org.opensaml.saml2.core.validator.ResponseSchemaValidator;
import org.opensaml.xml.util.XMLHelper;
import org.opensaml.xml.validation.ValidationException;

import eu.stork.mw.messages.saml.STORKResponse;

public class StorkResponseValidator extends ResponseSchemaValidator {

	private static final String CONSENT_ALLOWED_VALUE_1 = "urn:oasis:names:tc:SAML:2.0:consent:obtained";
	private static final String CONSENT_ALLOWED_VALUE_2 = "urn:oasis:names:tc:SAML:2.0:consent:prior";
	private static final String CONSENT_ALLOWED_VALUE_3 = "urn:oasis:names:tc:SAML:2.0:consent:curent-implicit";
	private static final String CONSENT_ALLOWED_VALUE_4 = "urn:oasis:names:tc:SAML:2.0:consent:curent-explicit";
	private static final String CONSENT_ALLOWED_VALUE_5 = "urn:oasis:names:tc:SAML:2.0:consent:unspecified";
	
	private static final int MAX_SIZE = 131072;

	/**
	 * Constructor
	 * 
	 */
	public StorkResponseValidator() {

		super();
	}

	/** {@inheritDoc} */
	public void validate(Response response) throws ValidationException {
		
		if (XMLHelper.prettyPrintXML(response.getDOM()).getBytes().length > MAX_SIZE) {
			throw new ValidationException("SAML Response exceeds max size.");
		}

		super.validate(response);

		STORKResponse resp = (STORKResponse) response;

		if (resp.getID() == null) {

			throw new ValidationException("ID is required");
		}

		if (resp.getInResponseTo() == null) {

			throw new ValidationException("InResponseTo is required");
		}

		if (resp.getVersion() == null) {
			
			throw new ValidationException("Version is required.");
		} else if(!resp.getVersion().equals(SAMLVersion.VERSION_20)) {

			throw new ValidationException("Version is invalid.");
		}

		if (resp.getIssueInstant() == null) {

			throw new ValidationException("IssueInstant is required");
		}

		if (resp.getDestination() == null) {

			throw new ValidationException("Destination is required");
		}

		// Consent is optional
		if (resp.getConsent() != null) {

			String consent = resp.getConsent();

			if (!consent.equals(CONSENT_ALLOWED_VALUE_1)
					&& !consent.equals(CONSENT_ALLOWED_VALUE_2)
					&& !consent.equals(CONSENT_ALLOWED_VALUE_3)
					&& !consent.equals(CONSENT_ALLOWED_VALUE_4)
					&& !consent.equals(CONSENT_ALLOWED_VALUE_5)) {

				throw new ValidationException("Consent is invalid.");
			}
		}


		 if (resp.getIssuer() == null) {
		
			 throw new ValidationException("Issuer is required.");
		 }

		if (resp.getStatus() == null) {

			throw new ValidationException("Status is required.");
		}

		
		if(resp.getSignature() == null) {
		        	
		 throw new ValidationException("Signature is required.");
		}

				
		if (resp.getStatus().getStatusCode().getValue().equals(StatusCode.SUCCESS)) {
			if (resp.getAssertions() == null || resp.getAssertions().size() == 0) {

				throw new ValidationException("Assertion is required");
			}
		}

	}

}