/*
    * RDFpro - An extensible tool for building stream-oriented RDF processing libraries.
    * 
    * Written in 2015 by Francesco Corcoglioniti with support by Alessio Palmero Aprosio and Marco
    * Rospocher. Contact info on http://rdfpro.fbk.eu/
    * 
    * To the extent possible under law, the authors have dedicated all copyright and related and
    * neighboring rights to this software to the public domain worldwide. This software is
    * distributed without any warranty.
   * 
   * You should have received a copy of the CC0 Public Domain Dedication along with this software.
   * If not, see <http://creativecommons.org/publicdomain/zero/1.0/>.
   */
  package eu.fbk.rdfpro.util;
  
  import java.util.Iterator;
  import java.util.Objects;
  import java.util.Set;
  
  import javax.annotation.Nullable;
  
  import org.openrdf.model.Model;
  import org.openrdf.model.Namespace;
  import org.openrdf.model.Resource;
  import org.openrdf.model.Statement;
  import org.openrdf.model.URI;
  import org.openrdf.model.Value;
  import org.openrdf.model.impl.ContextStatementImpl;
  import org.openrdf.model.util.ModelException;
  
  final class QuadModelModelAdapter extends QuadModel implements AutoCloseable {
  
      private static final long serialVersionUID = 1L;
  
      private final Model model;
  
      QuadModelModelAdapter(final Model model) {
          this.model = Objects.requireNonNull(model);
      }
  
      @Override
      public void close() throws Exception {
          IO.closeQuietly(this.model);
      }
  
      @Override
      protected Set<Namespace> doGetNamespaces() {
          return this.model.getNamespaces();
      }
  
      @Override
      protected Namespace doGetNamespace(final String prefix) {
          return this.model.getNamespace(prefix);
      }
  
      @Override
      protected Namespace doSetNamespace(final String prefix, @Nullable final String name) {
          if (name == null) {
              return this.model.removeNamespace(prefix);
          } else {
              final Namespace namespace = this.model.getNamespace(prefix);
              this.model.setNamespace(prefix, name);
              return namespace;
          }
      }
  
      @Override
      protected int doSize(@Nullable final Resource subj, @Nullable final URI pred,
              @Nullable final Value obj, final Resource[] ctxs) {
          return subj == null && pred == null && obj == null && ctxs.length == 0 ? this.model.size()
                  : this.model.filter(subj, pred, obj, ctxs).size();
      }
  
      @Override
      protected Iterator<Statement> doIterator(@Nullable final Resource subj,
              @Nullable final URI pred, @Nullable final Value obj, final Resource[] ctxs) {
          return this.model.filter(subj, pred, obj, ctxs).iterator();
      }
  
      @Override
      protected boolean doAdd(final Resource subj, final URI pred, final Value obj,
              final Resource[] ctxs) {
          if (ctxs.length == 0) {
              return doAddHelper(subj, pred, obj, CTX_DEFAULT);
          } else if (ctxs.length == 1) {
              return doAddHelper(subj, pred, obj, ctxs);
          } else {
              boolean modified = false;
              for (final Resource ctx : ctxs) {
                  final boolean m = doAddHelper(subj, pred, obj, new Resource[] { ctx });
                  modified |= m;
              }
              return modified;
          }
      }
  
      private boolean doAddHelper(final Resource subj, final URI pred, final Value obj,
              final Resource[] ctx) {
          final boolean added = this.model.add(subj, pred, obj, ctx);
         if (!added) {
             if (this.model.filter(subj, pred, obj, ctx).isEmpty()) {
                 throw new ModelException("Model already contains statement "
                         + new ContextStatementImpl(subj, pred, obj, ctx[0]));
             }
             return false;
         }
         return true;
     }
 
     @Override
     protected boolean doRemove(@Nullable final Resource subj, @Nullable final URI pred,
             @Nullable final Value obj, final Resource[] ctxs) {
         return this.model.remove(subj, pred, obj, ctxs);
     }
 
 }