1 files changed, 138 insertions, 0 deletions

diff --git a/src/main/scala/rsacomb/RSAComb.scala b/src/main/scala/rsacomb/RSAComb.scala
new file mode 100644
index 0000000..bc94a8d
--- /dev/null
+++ b/src/main/scala/rsacomb/RSAComb.scala
@@ -0,0 +1,138 @@
+package rsacomb
+
+import java.io.File
+import java.util.HashMap
+import java.util.stream.{Stream,Collectors}
+
+import org.semanticweb.owlapi.apibinding.OWLManager
+import org.semanticweb.owlapi.model.{AxiomType, ClassExpressionType, OWLObjectSomeValuesFrom}
+import org.semanticweb.owlapi.model.{OWLAxiom, OWLSubClassOfAxiom, OWLEquivalentClassesAxiom}
+import org.semanticweb.owlapi.model.OWLClassExpression
+import org.semanticweb.owlapi.model.OWLOntology
+import org.semanticweb.owlapi.model.OWLOntologyManager
+import org.semanticweb.owlapi.model.parameters.Imports
+
+import tech.oxfordsemantic.jrdfox.Prefixes
+import tech.oxfordsemantic.jrdfox.client.{ConnectionFactory, ServerConnection, DataStoreConnection}
+import tech.oxfordsemantic.jrdfox.client.UpdateType
+import tech.oxfordsemantic.jrdfox.logic.{Rule, Atom, Literal, Predicate, Term, Variable}
+import tech.oxfordsemantic.jrdfox.logic.{Bind, BuiltinFunctionCall}
+
+import scala.collection.JavaConverters._
+
+import rsacomb.SkolemStrategy
+
+class RSA(ontology : OWLOntology) {
+
+  /* Alternative constructor(s) */
+  def this(file : File) = this(RSA.loadOntology(file))
+
+  def getOntology : OWLOntology = ontology
+
+} // class RSA
+
+object RSA {
+
+  def loadOntology( onto : File ) : OWLOntology = {
+    /* Retrieve ontology manager */
+    val manager : OWLOntologyManager = OWLManager.createOWLOntologyManager()
+    /* Retrieve ontology */
+    manager.loadOntologyFromOntologyDocument(onto)
+  }
+
+  def isRSA( onto : OWLOntology ) : Boolean = {
+    /* TODO: Steps for RSA check
+     * 1) convert ontology axioms into LP rules
+     * 2) call RDFox on the onto and compute materialization
+     * 3) build graph from E(x,y) facts
+     * 4) check if the graph is tree-like
+     */
+
+    /* Ontology axiom convertion into LP rules */
+        for {
+      axiom <- onto.tboxAxioms(Imports.EXCLUDED).collect(Collectors.toList()).asScala
+      visitor = new RDFoxAxiomConverter(Variable.create("x"), SkolemStrategy.Constant(axiom.toString))
+      rule  <- axiom.accept(visitor)
+        } yield println(rule)
+
+    /* Return true for now... */
+    true
+  }
+
+} // object RSA
+
+object RSAComb {
+
+  val help : String = """
+      rsacomb - combined approach for CQ answering for RSA ontologies.
+
+      USAGE
+        rsacomb <path/to/ontology.owl> <path/to/query.sparql>
+
+      where
+         the ontology is expected to be an OWL file and the (single)
+         query a SPARQL query file.
+  """
+
+  def main( args : Array[String] ) : Unit = {
+
+    /* Simple arguments handling
+     *
+     * TODO: use something better later on
+     */
+
+    if (args.length < 2) {
+      println(help)
+      return ()
+    }
+
+    val ontologyPath = new File(args(0))
+    val queryPath = new File(args(1))
+
+    if (!ontologyPath.isFile || !queryPath.isFile) {
+      println("The provided arguments are not regular files.\n\n")
+      println(help)
+      return ()
+    }
+
+    /* Create RSA object from generic OWLOntology
+     *
+     * TODO: It might be required to check if the ontology in input is
+     * Horn-ALCHOIQ. At the moment we are assuming this is always the
+     * case.
+     */
+    val rsa = new RSA(ontologyPath)
+    RSA.isRSA(rsa.getOntology)
+
+    /* Build canonical model */
+    //val tboxCanon = rsa.canonicalModel()
+
+    /* Load query */
+    //val query = ...
+
+    /* Compute the filtering program from the given query */
+    //val tboxFilter = rsa.filteringProgram(query)
+
+    /* ... */
+
+    /* DEBUG ONLY */
+    println("Ok!")
+  }
+}
+
+/* Notes:
+ *
+ * To establish a connection with a local RDFox instance, do the
+ * following:
+ *
+ * ```
+ * val serverConnection : ServerConnection = ConnectionFactory.newServerConnection("rdfox:local", "", "")
+ * serverConnection.createDataStore("test","seq",new HashMap())
+ * val dataStoreConnection : DataStoreConnection = serverConnection.newDataStoreConnection("test")
+ * dataStoreConnection.importData(
+ *    UpdateType.ADDITION,
+ *    Prefixes.s_emptyPrefixes,
+ *    new File("./path/to/file")
+ * )
+ * ```
+ */