/*******************************************************************************
    * 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.tools;
  
  import java.math.BigInteger;
  import java.util.ArrayList;
  import java.util.List;
  
  import org.sat4j.core.Vec;
  import org.sat4j.pb.IPBSolver;
  import org.sat4j.pb.ObjectiveFunction;
  import org.sat4j.specs.ContradictionException;
  import org.sat4j.specs.IConstr;
  import org.sat4j.specs.IVec;
  import org.sat4j.specs.IVecInt;
  import org.sat4j.specs.TimeoutException;
  import org.sat4j.tools.LexicoDecorator;
  
  public class LexicoDecoratorPB extends LexicoDecorator<IPBSolver> implements
          IPBSolver {
  
      /**
  	 * 
  	 */
      private static final long serialVersionUID = 1L;
  
      private final List<ObjectiveFunction> objs = new ArrayList<ObjectiveFunction>();
      private BigInteger bigCurrentValue;
  
      public LexicoDecoratorPB(IPBSolver solver) {
          super(solver);
      }
  
      public IConstr addPseudoBoolean(IVecInt lits, IVec<BigInteger> coeffs,
              boolean moreThan, BigInteger d) throws ContradictionException {
          return decorated().addPseudoBoolean(lits, coeffs, moreThan, d);
      }
  
      public void setObjectiveFunction(ObjectiveFunction obj) {
          throw new UnsupportedOperationException();
  
      }
  
      public ObjectiveFunction getObjectiveFunction() {
          return this.objs.get(this.currentCriterion);
      }
  
      @Override
      public boolean admitABetterSolution(IVecInt assumps)
              throws TimeoutException {
          decorated().setObjectiveFunction(this.objs.get(this.currentCriterion));
          return super.admitABetterSolution(assumps);
      }
  
      @Override
      public void addCriterion(IVecInt literals) {
          this.objs.add(new ObjectiveFunction(literals, new Vec<BigInteger>(
                  literals.size(), BigInteger.ONE)));
      }
  
      public void addCriterion(IVecInt literals, IVec<BigInteger> coefs) {
          this.objs.add(new ObjectiveFunction(literals, coefs));
      }
  
      @Override
      protected Number evaluate() {
          this.bigCurrentValue = this.objs.get(this.currentCriterion)
                  .calculateDegree(this);
          return this.bigCurrentValue;
      }
  
      @Override
     protected Number evaluate(int criterion) {
         return this.objs.get(criterion).calculateDegree(this);
     }
 
     @Override
     protected void fixCriterionValue() throws ContradictionException {
         if (bigCurrentValue == null) {
             throw new ContradictionException("no current value computed!");
         }
         addExactly(this.objs.get(this.currentCriterion).getVars(), this.objs
                 .get(this.currentCriterion).getCoeffs(), this.bigCurrentValue);
     }
 
     @Override
     protected IConstr discardSolutionsForOptimizing()
             throws ContradictionException {
         return addAtMost(this.objs.get(this.currentCriterion).getVars(),
                 this.objs.get(this.currentCriterion).getCoeffs(),
                 this.bigCurrentValue.subtract(BigInteger.ONE));
     }
 
     @Override
     public int numberOfCriteria() {
         return this.objs.size();
     }
 
     public IConstr addAtMost(IVecInt literals, IVecInt coeffs, int degree)
             throws ContradictionException {
         return decorated().addAtMost(literals, coeffs, degree);
     }
 
     public IConstr addAtMost(IVecInt literals, IVec<BigInteger> coeffs,
             BigInteger degree) throws ContradictionException {
         return decorated().addAtMost(literals, coeffs, degree);
     }
 
     public IConstr addAtLeast(IVecInt literals, IVecInt coeffs, int degree)
             throws ContradictionException {
         return decorated().addAtLeast(literals, coeffs, degree);
     }
 
     public IConstr addAtLeast(IVecInt literals, IVec<BigInteger> coeffs,
             BigInteger degree) throws ContradictionException {
         return decorated().addAtLeast(literals, coeffs, degree);
     }
 
     public IConstr addExactly(IVecInt literals, IVecInt coeffs, int weight)
             throws ContradictionException {
         return decorated().addExactly(literals, coeffs, weight);
     }
 
     public IConstr addExactly(IVecInt literals, IVec<BigInteger> coeffs,
             BigInteger weight) throws ContradictionException {
         return decorated().addExactly(literals, coeffs, weight);
     }
 
 }