/*
    * Copyright 2017 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.openehealth.ipf.commons.ihe.hpd;
  
  import org.apache.commons.lang3.StringUtils;
  import org.openehealth.ipf.commons.core.modules.api.ValidationException;
  import org.openehealth.ipf.commons.ihe.hpd.stub.chpidd.DownloadRequest;
  import org.openehealth.ipf.commons.ihe.hpd.stub.chpidd.DownloadResponse;
  import org.openehealth.ipf.commons.ihe.hpd.stub.dsmlv2.BatchRequest;
  import org.openehealth.ipf.commons.ihe.hpd.stub.dsmlv2.BatchResponse;
  import org.openehealth.ipf.commons.ihe.hpd.stub.dsmlv2.DsmlMessage;
  import org.openehealth.ipf.commons.ihe.hpd.stub.dsmlv2.ErrorResponse.ErrorType;
  import org.openehealth.ipf.commons.ihe.hpd.stub.dsmlv2.SearchRequest;
  import org.openehealth.ipf.commons.xml.XsdValidator;
  
  import javax.naming.InvalidNameException;
  import javax.naming.ldap.LdapName;
  import javax.naming.ldap.Rdn;
  import javax.xml.bind.JAXBContext;
  import javax.xml.bind.JAXBException;
  import javax.xml.bind.util.JAXBSource;
  import javax.xml.transform.Source;
  
  /**
   * @author Dmytro Rud
   */
  public class HpdValidator {
      private static final JAXBContext JAXB_CONTEXT;
      static {
          try {
              JAXB_CONTEXT = JAXBContext.newInstance(
                      org.openehealth.ipf.commons.ihe.hpd.stub.dsmlv2.ObjectFactory.class,
                      org.openehealth.ipf.commons.ihe.hpd.stub.chpidd.ObjectFactory.class);
          } catch (JAXBException e) {
              throw new RuntimeException(e);
          }
      }
  
      private static final XsdValidator XSD_VALIDATOR = new XsdValidator();
  
      private void check(boolean condition, String message) {
          if (! condition) {
              throw new HpdException(message, ErrorType.MALFORMED_REQUEST);
          }
      }
  
      private static void validateWithXsd(Object object, String schemaName) {
          try {
              Source source = new JAXBSource(JAXB_CONTEXT, object);
              XSD_VALIDATOR.validate(source, schemaName);
          } catch (ValidationException e) {
              throw new HpdException(e, ErrorType.MALFORMED_REQUEST);
          } catch (Exception e) {
              throw new HpdException(e, ErrorType.OTHER);
          }
      }
  
      public void validateBatchRequest(BatchRequest request) {
          validateWithXsd(request, "/schema/DSMLv2.xsd");
          check(request.getBatchRequests() != null, "Request list is null");
          check(!request.getBatchRequests().isEmpty(), "Request list is empty");
          for(DsmlMessage dsml : request.getBatchRequests()) {
              check(dsml instanceof SearchRequest, "Only SearchRequests are supported");
              validateSearchRequest((SearchRequest) dsml);
          }
      }
  
      private void validateSearchRequest(SearchRequest request) {
          try {
              LdapName ldapName = new LdapName(request.getDn());
              boolean oCheck = false;
              boolean dcCheck = false;
              for (Rdn rdn : ldapName.getRdns()) {
                  String value = (String) rdn.getValue();
                  switch (rdn.getType().toLowerCase()) {
                      case "o":
                          oCheck = StringUtils.isNotBlank(value);
                          break;
                      case "dc":
                          dcCheck = "HPD".equals(value);
                          break;
                  }
              }
              check(oCheck, "Missing DN.O");
              check(dcCheck, "DN.DC not equal to 'HPD'");
          } catch (InvalidNameException e) {
             throw new HpdException(e, ErrorType.MALFORMED_REQUEST);
         }
     }
 
     public void validateBatchResponse(BatchResponse response) {
         validateWithXsd(response, "/schema/DSMLv2.xsd");
     }
 
     public void validateDownloadRequest(DownloadRequest request) {
         validateWithXsd(request, "/schema/PIDD.xsd");
     }
 
     public void validateDownloadResponse(DownloadResponse response) {
         validateWithXsd(response, "/schema/PIDD.xsd");
     }
 }