/*
 * Copyright 2017 Graz University of Technology EAAF-Core Components has been developed in a
 * cooperation between EGIZ, A-SIT Plus, A-SIT, and Graz University of Technology.
 *
 * Licensed under the EUPL, Version 1.2 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:
 * https://joinup.ec.europa.eu/news/understanding-eupl-v12
 *
 * 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.egiz.eaaf.modules.pvp2.impl.validation.metadata;

import javax.xml.transform.dom.DOMSource;
import javax.xml.validation.Schema;
import javax.xml.validation.Validator;

import at.gv.egiz.eaaf.modules.pvp2.exception.SchemaValidationException;

import org.opensaml.core.xml.XMLObject;
import org.opensaml.saml.common.xml.SAMLSchemaBuilder;
import org.opensaml.saml.common.xml.SAMLSchemaBuilder.SAML1Version;
import org.opensaml.saml.metadata.resolver.filter.FilterException;
import org.opensaml.saml.metadata.resolver.filter.MetadataFilter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class SchemaValidationFilter implements MetadataFilter {
  private static final Logger log = LoggerFactory.getLogger(SchemaValidationFilter.class);
  private boolean isActive = true;

  private static SAMLSchemaBuilder schemaBuilder = new SAMLSchemaBuilder(SAML1Version.SAML_11);

  /**
   * XML Schema validation filter for SAML2 metadata.
   * <p>Schemavalidation is active by default</p>
   */
  public SchemaValidationFilter() {

  }

  /**
   * XML Schema validation filter for SAML2 metadata.
   *
   * @param useSchemaValidation <code>true</code> XML schema validation is active, otherwise <code>false</code>
   */
  public SchemaValidationFilter(final boolean useSchemaValidation) {
    this.isActive = useSchemaValidation;
  }

  /*
   * (non-Javadoc)
   *
   * @see
   * org.opensaml.saml2.metadata.provider.MetadataFilter#doFilter(org.opensaml.xml
   * .XMLObject)
   */
  @Override
  public XMLObject filter(final XMLObject arg0) throws FilterException {

    if (isActive) {
      try {
        final Schema test = schemaBuilder.getSAMLSchema();
        final Validator val = test.newValidator();
        final DOMSource source = new DOMSource(arg0.getDOM());
        val.validate(source);
        log.info("Metadata Schema validation check done OK");

      } catch (final Exception e) {
        if (log.isDebugEnabled() || log.isTraceEnabled()) {
          log.warn("Metadata Schema validation FAILED with exception:", e);
        } else {
          log.warn("Metadata Schema validation FAILED with message: " + e.getMessage());
        }

        throw new FilterException(new SchemaValidationException("internal.pvp.03",
            new Object[] { e.getMessage() }, e));
      }

    } else {
      log.info("Metadata Schema validation check is DEACTIVATED!");

    }

    return arg0;
  }

}