/*
    * 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 ca.uhn.fhir.rest.client.api.IClientInterceptor;
  import ca.uhn.fhir.rest.client.api.IHttpRequest;
  import ca.uhn.fhir.rest.client.api.IHttpResponse;
  import org.apache.camel.Exchange;
  import org.openehealth.ipf.platform.camel.ihe.fhir.core.FhirEndpoint;
  import org.openehealth.ipf.platform.camel.ihe.fhir.core.HapiClientInterceptorFactory;
  
  import java.io.IOException;
  import java.util.Map;
  
  import static org.openehealth.ipf.commons.ihe.core.Constants.*;
  
  /**
   * HAPI interceptor that adds tracing information from the Camel message headers, if available,
   * to the HTTP request headers
   *
   * @author Christian Ohr
   * @since 3.2
   */
  public class ProducerTracingInterceptor implements IClientInterceptor, HapiClientInterceptorFactory {
  
      private final Map<String, Object> headers;
  
      private ProducerTracingInterceptor(Map<String, Object> headers) {
          this.headers = headers;
      }
  
      @Override
      public IClientInterceptor newInstance(FhirEndpoint endpoint, Exchange exchange) {
          return new ProducerTracingInterceptor(exchange.getIn().getHeaders());
      }
  
      @Override
      public void interceptRequest(IHttpRequest request) {
          if (headers.containsKey(TRACE_ID)) {
              request.addHeader(TRACE_ID, headers.get(TRACE_ID).toString());
          }
          if (headers.containsKey(SPAN_ID)) {
              request.addHeader(SPAN_ID, headers.get(SPAN_ID).toString());
          }
          if (headers.containsKey(PARENT_SPAN_ID)) {
              request.addHeader(PARENT_SPAN_ID, headers.get(PARENT_SPAN_ID).toString());
          }
          if (headers.containsKey(SAMPLED)) {
              request.addHeader(SAMPLED, headers.get(SAMPLED).toString());
          }
          if (headers.containsKey(FLAGS)) {
              request.addHeader(FLAGS, headers.get(FLAGS).toString());
          }
      }
  
      @Override
      public void interceptResponse(IHttpResponse theResponse) throws IOException {
          // nothing to do here?
      }
  }