/*
    * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2006 Daniel Le
    * Berre
    * 
    * Based on the original minisat specification from:
    * 
    * An extensible SAT solver. Niklas E?n and Niklas S?rensson. Proceedings of the
    * Sixth International Conference on Theory and Applications of Satisfiability
    * Testing, LNCS 2919, pp 502-518, 2003.
   * 
   * This library is free software; you can redistribute it and/or modify it under
   * the terms of the GNU Lesser General Public License as published by the Free
   * Software Foundation; either version 2.1 of the License, or (at your option)
   * any later version.
   * 
   * This library is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
   * FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
   * details.
   * 
   * You should have received a copy of the GNU Lesser General Public License
   * along with this library; if not, write to the Free Software Foundation, Inc.,
   * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   * 
   */
  
  package org.sat4j.tools;
  
  import java.io.ObjectInputStream;
  import java.io.PrintStream;
  import java.io.PrintWriter;
  import java.math.BigInteger;
  import java.util.Map;
  
  import org.sat4j.specs.ContradictionException;
  import org.sat4j.specs.IConstr;
  import org.sat4j.specs.ISolver;
  import org.sat4j.specs.IVec;
  import org.sat4j.specs.IVecInt;
  import org.sat4j.specs.TimeoutException;
  
  /**
   * Solver used to display in a writer the CNF instance in Dimacs format.
   * 
   * That solver is useful to produce CNF files to be used by third party solvers.
   * 
   * @author leberre
   * 
   */
  public class DimacsOutputSolver implements ISolver {
  
      /**
       * 
       */
      private static final long serialVersionUID = 1L;
  
      private transient PrintWriter out;
  
      private int nbvars;
  
      private int nbclauses;
  
      private boolean fixedNbClauses = false;
  
      private boolean firstConstr = true;
      
      public DimacsOutputSolver() {
          this(new PrintWriter(System.out, true));
      }
  
      public DimacsOutputSolver(PrintWriter pw) {
          out = pw;
      }
  
      private void readObject(ObjectInputStream stream) {
          out = new PrintWriter(System.out, true);
      }
  
      public int newVar() {
          return 0;
      }
  
      public int newVar(int howmany) {
          out.print("p cnf " + howmany);
          nbvars = howmany;
          return 0;
      }
  
      public void setExpectedNumberOfClauses(int nb) {
          out.println(" " + nb);
          nbclauses = nb;
          fixedNbClauses = true;
      }
  
      public IConstr addClause(IVecInt literals) throws ContradictionException {
          if (firstConstr) {
              if (!fixedNbClauses) {
                  out.println(" XXXXXX");
              }
             firstConstr = false;
         }
         for (int i : literals)
             out.print(i + " ");
         out.println("0");
         return null;        
     }
 
     public boolean removeConstr(IConstr c) {
         throw new UnsupportedOperationException();
     }
 
     public void addAllClauses(IVec<IVecInt> clauses)
             throws ContradictionException {
         throw new UnsupportedOperationException();
     }
 
     public IConstr addAtMost(IVecInt literals, int degree)
             throws ContradictionException {
         if (degree > 1) {
             throw new UnsupportedOperationException(
                     "Not a clausal problem! degree " + degree);
         }
         assert degree == 1;
         if (firstConstr) {
             if (!fixedNbClauses) {
                 out.println("XXXXXX");
             }
             firstConstr = false;
         }
         for (int i = 0; i <= literals.size(); i++) {
             for (int j = i + 1; j < literals.size(); j++) {
                 out.println("" + (-literals.get(i)) + " " + (-literals.get(j))
                         + " 0");
             }
         }
         return null;
     }
 
     public IConstr addAtLeast(IVecInt literals, int degree)
             throws ContradictionException {
         if (degree > 1) {
             throw new UnsupportedOperationException(
                     "Not a clausal problem! degree " + degree);
         }
         assert degree == 1;
         return addClause(literals);
     }
 
     public IConstr addPseudoBoolean(IVecInt lits, IVec<BigInteger> coeffs,
             boolean moreThan, BigInteger d) throws ContradictionException {
         throw new UnsupportedOperationException();
     }
 
     public void setTimeout(int t) {
         // TODO Auto-generated method stub
 
     }
 
     public void setTimeoutMs(long t) {
         // TODO Auto-generated method stub
     }
 
     public int getTimeout() {
         // TODO Auto-generated method stub
         return 0;
     }
 
     public void reset() {
         fixedNbClauses = false;
         firstConstr  = true;
 
     }
 
     public void printStat(PrintStream out, String prefix) {
         // TODO Auto-generated method stub
 
     }
 
     public void printStat(PrintWriter out, String prefix) {
         // TODO Auto-generated method stub
 
     }
 
     public Map<String, Number> getStat() {
         // TODO Auto-generated method stub
         return null;
     }
 
     public String toString(String prefix) {
         return "Dimacs output solver";
     }
 
     public void clearLearntClauses() {
         // TODO Auto-generated method stub
 
     }
 
     public int[] model() {
         throw new UnsupportedOperationException();
     }
 
     public boolean model(int var) {
         throw new UnsupportedOperationException();
     }
 
     public boolean isSatisfiable() throws TimeoutException {
         throw new TimeoutException("There is no real solver behind!");
     }
 
     public boolean isSatisfiable(IVecInt assumps) throws TimeoutException {
         throw new TimeoutException("There is no real solver behind!");
     }
 
     public int[] findModel() throws TimeoutException {
         throw new UnsupportedOperationException();
     }
 
     public int[] findModel(IVecInt assumps) throws TimeoutException {
         throw new UnsupportedOperationException();
     }
 
     public int nConstraints() {
         return nbclauses;
     }
 
     public int nVars() {
         // TODO Auto-generated method stub
         return nbvars;
     }
 
 }