forgotten class

sparqlmap-mapping/src/main/java/org/aksw/sparqlmap/core/normalizer/DescribeRewriter.java

@@ -0,0 +1,132 @@
+package org.aksw.sparqlmap.core.normalizer;
+
+import java.util.List;
+import java.util.Random;
+import java.util.stream.Collectors;
+
+import org.aksw.sparqlmap.core.TranslationContext;
+import org.apache.jena.graph.Node;
+import org.apache.jena.graph.Triple;
+import org.apache.jena.query.Query;
+import org.apache.jena.sparql.algebra.AlgebraGenerator;
+import org.apache.jena.sparql.algebra.OpVars;
+import org.apache.jena.sparql.core.BasicPattern;
+import org.apache.jena.sparql.core.Var;
+import org.apache.jena.sparql.syntax.ElementFilter;
+import org.apache.jena.sparql.syntax.ElementGroup;
+import org.apache.jena.sparql.syntax.ElementTriplesBlock;
+import org.apache.jena.sparql.syntax.ElementUnion;
+import org.apache.jena.sparql.syntax.Template;
+
+import com.google.common.collect.Lists;
+
+
+public class DescribeRewriter {
+
+
+
+  public static void rewriteDescribe(TranslationContext tc){
+
+      if(tc.getQuery().isDescribeType()){
+        Query describe = tc.getQuery();
+        String suf = createVariablesSuffix(describe);
+        Query result = new Query();
+        result.setQueryConstructType();
+        List<Node> describedResources;
+
+        if(describe.getResultURIs().isEmpty()){
+          describedResources =  describe.getProject().getVars().stream().map(var -> (Node) var).collect(Collectors.toList());
+        }else{
+          describedResources = describe.getResultURIs();
+
+        }
+
+
+
+
+
+        for(Node todesc: describedResources){
+          List<List<Triple>> allNested = createList(todesc, suf);
+
+          List<Triple> all = allNested.stream().flatMap(list -> list.stream()).collect(Collectors.toList());
+
+          result.setConstructTemplate(new Template( BasicPattern.wrap(all)));
+
+          ElementUnion union = new ElementUnion();
+
+          allNested.forEach(list -> union.addElement(new ElementTriplesBlock(BasicPattern.wrap(list))));
+
+
+          ElementGroup eg = new ElementGroup();
+
+          eg.addElement(union);
+          result.setQueryPattern(eg);
+
+
+
+          if(describe.getQueryPattern()!=null){
+            ElementGroup group = new ElementGroup();
+            group.addElement(describe.getQueryPattern());
+            group.addElement(result.getQueryPattern());
+            result.setQueryPattern(group);
+          }
+        }
+
+
+
+
+
+
+
+
+        describe.getGraphURIs().forEach(uri -> result.addGraphURI(uri));
+        describe.getNamedGraphURIs().forEach(uri-> result.addNamedGraphURI(uri));
+        tc.setQuery(result);
+
+      }
+
+
+
+  }
+
+
+  private static List<List<Triple>> createList(Node describedResource, String suf){
+    //create the triples used both in the template and the where condition.
+    return Lists.newArrayList( 
+      Lists.newArrayList(
+          new Triple(Var.alloc("si0_" + suf),Var.alloc("pi0_"+ suf),describedResource)),
+
+//      Lists.newArrayList(
+//          new Triple(Var.alloc("si12_"+ suf),Var.alloc("pi12_"+ suf),Var.alloc("si10_"+ suf)),
+//          new Triple(Var.alloc("si10_"+ suf),Var.alloc("pi10_"+ suf),describedResource)),
+//
+      Lists.newArrayList(
+          new Triple(describedResource, Var.alloc("po0_"+ suf),Var.alloc("oo0_"+ suf)))
+
+//      Lists.newArrayList(
+//          new Triple(describedResource, Var.alloc("po10_"+ suf),Var.alloc("oo10_"+ suf)),
+//          new Triple(Var.alloc("oo10_"+ suf), Var.alloc("po11_"+ suf),Var.alloc("oo11_"+ suf)))
+    );
+
+  }
+
+  private static String createVariablesSuffix(Query query){
+
+    List<String> vars = OpVars.mentionedVars(new AlgebraGenerator().compile(query)).stream().map(var -> var.getName()).collect(Collectors.toList());
+
+    String prefix = null;
+
+    Random random = new Random();
+
+    while(prefix == null){
+      String prefix_cand = "sm_" + random.nextInt(10000);
+      if(!vars.stream().anyMatch(v -> v.startsWith(prefix_cand))){
+        prefix = prefix_cand;
+        break;
+      }
+    }
+    return prefix;
+
+  }
+
+}