/*******************************************************************************
    * SAT4J: a SATisfiability library for Java Copyright (C) 2004, 2012 Artois University and CNRS
    *
    * All rights reserved. This program and the accompanying materials
    * are made available under the terms of the Eclipse Public License v1.0
    * which accompanies this distribution, and is available at
    *  http://www.eclipse.org/legal/epl-v10.html
    *
    * Alternatively, the contents of this file may be used under the terms of
   * either the GNU Lesser General Public License Version 2.1 or later (the
   * "LGPL"), in which case the provisions of the LGPL are applicable instead
   * of those above. If you wish to allow use of your version of this file only
   * under the terms of the LGPL, and not to allow others to use your version of
   * this file under the terms of the EPL, indicate your decision by deleting
   * the provisions above and replace them with the notice and other provisions
   * required by the LGPL. If you do not delete the provisions above, a recipient
   * may use your version of this file under the terms of the EPL or the LGPL.
   *
   * Based on the original MiniSat specification from:
   *
   * An extensible SAT solver. Niklas Een and Niklas Sorensson. Proceedings of the
   * Sixth International Conference on Theory and Applications of Satisfiability
   * Testing, LNCS 2919, pp 502-518, 2003.
   *
   * See www.minisat.se for the original solver in C++.
   *
   * Contributors:
   *   CRIL - initial API and implementation
   *******************************************************************************/
  package org.sat4j.pb.reader;
  
  import java.io.FileNotFoundException;
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.net.URL;
  import java.util.Locale;
  
  import org.sat4j.pb.IPBSolver;
  import org.sat4j.reader.InstanceReader;
  import org.sat4j.reader.ParseFormatException;
  import org.sat4j.reader.Reader;
  import org.sat4j.specs.ContradictionException;
  import org.sat4j.specs.IProblem;
  
  /**
   * An reader having the responsibility to choose the right reader according to
   * the input.
   * 
   * @author leberre
   */
  public class PBInstanceReader extends InstanceReader {
  
      private OPBReader2007 opb;
  
      private Reader reader = null;
  
      private final IPBSolver solver;
  
      public PBInstanceReader(IPBSolver solver) {
          super(solver);
          this.solver = solver;
      }
  
      private Reader getDefaultOPBReader() {
          if (this.opb == null) {
              this.opb = new OPBReader2007(this.solver);
          }
          return this.opb;
      }
  
      public boolean hasObjectiveFunction() {
          return this.opb.hasObjFunc;
      }
  
      @Override
      public IProblem parseInstance(String filename)
              throws FileNotFoundException, ParseFormatException, IOException,
              ContradictionException {
          String fname;
          boolean isHttp = false;
          String tempFileName = "";
          String prefix = "";
  
          if (filename.startsWith("http://")) {
              isHttp = true;
              tempFileName = filename;
              filename = filename.substring(filename.lastIndexOf('/'),
                      filename.length() - 1);
          }
  
          if (filename.indexOf(':') != -1) {
  
              String[] parts = filename.split(":");
              filename = parts[1];
              prefix = parts[0].toUpperCase(Locale.getDefault());
  
          }
  
          if (filename.endsWith(".gz")) {
             fname = filename.substring(0, filename.lastIndexOf('.'));
         } else {
             fname = filename;
         }
         if (fname.endsWith(".opb") || "PB".equals(prefix)) {
             this.reader = getDefaultOPBReader();
         } else {
             return super.parseInstance(filename);
         }
 
         if (isHttp) {
             return this.reader
                     .parseInstance(new URL(tempFileName).openStream());
         }
         return this.reader.parseInstance(filename);
     }
 
     @Override
     @Deprecated
     public String decode(int[] model) {
         return this.reader.decode(model);
     }
 
     @Override
     public void decode(int[] model, PrintWriter out) {
         this.reader.decode(model, out);
     }
 }