content: /*
   *  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.
   *
   *  See the NOTICE file distributed with this work for additional
   *  information regarding copyright ownership.
   */
  
  package org.seaborne.delta.server.local.handlers;
  
  import java.net.http.HttpRequest.BodyPublishers;
  import java.util.ArrayList ;
  import java.util.List ;
  
  import org.apache.jena.atlas.io.IndentedLineBuffer ;
  import org.apache.jena.atlas.web.HttpException ;
  import org.apache.jena.http.HttpOp;
  import org.apache.jena.query.ARQ ;
  import org.apache.jena.riot.WebContent ;
  import org.seaborne.delta.server.local.DPS;
  import org.seaborne.delta.server.local.Patch;
  import org.seaborne.delta.server.local.PatchHandler;
  import org.apache.jena.rdfpatch.RDFChanges ;
  import org.apache.jena.rdfpatch.changes.RDFChangesWriteUpdate ;
  
  /** Convert a patch to SPARQL Update and send to some endpoints */
  public class PHandlerSPARQLUpdate implements PatchHandler {
  
      // SPARQL Update services to poke
      private List<String> updateEndpoints = new ArrayList<>() ;
      public PHandlerSPARQLUpdate addEndpoint(String url) {
          updateEndpoints.add(url) ;
          return this ;
      }
  
      public PHandlerSPARQLUpdate() { }
  
      private Object dft = ARQ.getContext().get(ARQ.constantBNodeLabels) ;
  
      @Override
      public void handle(Patch patch) {
          IndentedLineBuffer x = new IndentedLineBuffer() ;
          RDFChanges scData = new RDFChangesWriteUpdate(x) ;
          patch.play(scData);
          x.flush();
          String reqStr = x.asString() ;
          updateEndpoints.forEach((ep)->{
              try { HttpOp.httpPost(ep, WebContent.contentTypeSPARQLUpdate, BodyPublishers.ofString(reqStr)) ; }
              catch (HttpException ex) { DPS.LOG.warn("Failed to send to "+ep) ; }
          }) ;
      }
  }
  
  