package de.tud.plt.r43ples.existentobjects;
   
   import org.apache.jena.query.QuerySolution;
   import org.apache.jena.query.ResultSet;
   import de.tud.plt.r43ples.management.Config;
   import de.tud.plt.r43ples.triplestoreInterface.TripleStoreInterfaceSingleton;
   import org.apache.logging.log4j.LogManager;
   import org.apache.logging.log4j.Logger;
   
  import java.util.HashMap;
  
  /**
   * Provides information of all revised graphs.
   *
   * @author Stephan Hensel
   */
  public class RevisionControl {
  
      /** The logger. **/
      private Logger logger = LogManager.getLogger(RevisionControl.class);
  
  
      /**
       * Get a hash map of all revised graphs in R43ples.
       * Key is the corresponding graph name.
       *
       * @return the hash map of revised graphs
       */
      public HashMap<String, RevisionGraph> getRevisedGraphs() {
          // As new graphs can be added there is no private variable storing the currently revised graphs
          HashMap<String, RevisionGraph> revisionGraphMap = new HashMap<>();
          String sparqlQuery = Config.prefixes
                  + String.format(""
                  + "SELECT DISTINCT ?graph "
                  + "WHERE {"
                  + " GRAPH <%s> {  ?graph a rmo:RevisionGraph }"
                  + "} ORDER BY ?graph", Config.revision_graph);
          ResultSet results = TripleStoreInterfaceSingleton.get().executeSelectQuery(sparqlQuery);
          while (results.hasNext()) {
              QuerySolution qs = results.next();
              String graphName = qs.getResource("graph").toString();
              RevisionGraph revisionGraph = new RevisionGraph(graphName);
              revisionGraphMap.put(graphName, revisionGraph);
          }
  
          return revisionGraphMap;
      }
  
  }