/*
    * Copyright 2016 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.platform.camel.ihe.fhir.core.intercept.producer;
  
  import org.apache.camel.Exchange;
  import org.hl7.fhir.instance.model.api.IBaseResource;
  import org.openehealth.ipf.commons.audit.AuditContext;
  import org.openehealth.ipf.commons.audit.codes.EventOutcomeIndicator;
  import org.openehealth.ipf.commons.ihe.core.atna.AuditStrategy;
  import org.openehealth.ipf.commons.ihe.fhir.audit.FhirAuditDataset;
  import org.openehealth.ipf.platform.camel.ihe.atna.interceptor.AuditInterceptor;
  import org.openehealth.ipf.platform.camel.ihe.core.InterceptorSupport;
  import org.openehealth.ipf.platform.camel.ihe.fhir.core.FhirComponent;
  import org.openehealth.ipf.platform.camel.ihe.fhir.core.FhirEndpoint;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import static java.util.Objects.requireNonNull;
  import static org.openehealth.ipf.platform.camel.core.util.Exchanges.resultMessage;
  
  
  /**
   * Consumer-side FHIR ATNA auditing Camel interceptor.
   *
   * @author Christian Ohr
   * @since 3.1
   */
  public class ProducerAuditInterceptor<AuditDatasetType extends FhirAuditDataset>
          extends InterceptorSupport<FhirEndpoint<AuditDatasetType, FhirComponent<AuditDatasetType>>>
          implements AuditInterceptor<AuditDatasetType, FhirEndpoint<AuditDatasetType, FhirComponent<AuditDatasetType>>> {
  
      private static final Logger LOG = LoggerFactory.getLogger(ProducerAuditInterceptor.class);
  
      private final AuditContext auditContext;
  
      public ProducerAuditInterceptor(AuditContext auditContext) {
          this.auditContext = requireNonNull(auditContext);
      }
  
      @Override
      public void process(Exchange exchange) throws Exception {
          IBaseResource msg = exchange.getIn().getBody(IBaseResource.class);
  
          AuditDatasetType auditDataset = createAndEnrichAuditDatasetFromRequest(getAuditStrategy(), exchange, msg);
          determineParticipantsAddresses(exchange, auditDataset);
  
          boolean failed = false;
          try {
              getWrappedProcessor().process(exchange);
              IBaseResource result = resultMessage(exchange).getBody(IBaseResource.class);
              failed = !enrichAuditDatasetFromResponse(getAuditStrategy(), auditDataset, result);
          } catch (Exception e) {
              // FHIR exception or unexpected exception
              failed = true;
              throw e;
          } finally {
              if (auditDataset != null) {
                  auditDataset.setEventOutcomeIndicator(failed ?
                          EventOutcomeIndicator.MajorFailure :
                          EventOutcomeIndicator.Success);
                  getAuditStrategy().doAudit(auditContext, auditDataset);
              }
          }
      }
  
      @Override
      public void determineParticipantsAddresses(Exchange exchange, AuditDatasetType auditDataset) {
      }
  
      @Override
      public AuditStrategy<AuditDatasetType> getAuditStrategy() {
          return getEndpoint().getClientAuditStrategy();
      }
  
      /**
       * Creates a new audit dataset and enriches it with data from the request
       * message.  All exception are ignored.
       *
       * @return newly created audit dataset or <code>null</code> when creation failed.
       */
      private AuditDatasetType createAndEnrichAuditDatasetFromRequest(AuditStrategy<AuditDatasetType> strategy, Exchange exchange, IBaseResource msg) {
          try {
              AuditDatasetType auditDataset = strategy.createAuditDataset();
              auditDataset.setSourceUserId("unknown");
              auditDataset.setDestinationUserId(exchange.getProperty("CamelToEndpoint").toString());
  
             // TODO set client-side headers
             return strategy.enrichAuditDatasetFromRequest(auditDataset, msg, exchange.getIn().getHeaders());
         } catch (Exception e) {
             LOG.error("Exception when enriching audit dataset from request", e);
             return null;
         }
     }
 
 
     /**
      * Enriches the given audit dataset with data from the response message.
      * All exception are ignored.
      */
     private boolean enrichAuditDatasetFromResponse(AuditStrategy<AuditDatasetType> strategy, AuditDatasetType auditDataset, IBaseResource response) {
         return strategy.enrichAuditDatasetFromResponse(auditDataset, response, auditContext);
     }
 
 
 }