/*******************************************************************************
   * SAT4J: a SATisfiability library for Java Copyright (C) 2004-2008 Daniel Le Berre
   *
   * 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++.
  * 
  *******************************************************************************/
  package org.sat4j.minisat.core;
  
  import java.io.FileWriter;
  import java.io.IOException;
  import java.io.ObjectInputStream;
  import java.io.PrintWriter;
  import java.io.Writer;
  
  import org.sat4j.core.Vec;
  
  /**
   * Class allowing to express the search as a tree in the dot language. The
   * resulting file can be viewed in a tool like <a
   * href="http://www.graphviz.org/">Graphviz</a>
   * 
   * To use only on small benchmarks.
   * 
   * Note that also does not make sense to use such a listener on a distributed or
   * remote solver.
   * 
   * @author daniel
   * 
   */
  public class DotSearchListener implements SearchListener {
  
      /**
       * 
       */
      private static final long serialVersionUID = 1L;
  
      private final Vec<String> pile;
  
      private String currentNodeName = null;
  
      private transient Writer out;
  
      private boolean estOrange = false;
  
      public DotSearchListener(final String fileNameToSave) {
          pile = new Vec<String>();
          try {
              out = new FileWriter(fileNameToSave);
          } catch (IOException e) {
              System.err.println("Problem when created file.");
          }
      }
  
      public final void assuming(final int p) {
          final int absP = Math.abs(p);
          String newName;
  
          if (currentNodeName == null) {
              newName = ""+absP;
              pile.push(newName);
              saveLine(lineTab("\"" + newName + "\"" + "[label=\"" + newName
                      + "\", shape=circle, color=blue, style=filled]"));
          } else {
              newName = currentNodeName;
              pile.push(newName);
              saveLine(lineTab("\"" + newName + "\"" + "[label=\""
                      + absP
                      + "\", shape=circle, color=blue, style=filled]"));
          }
          currentNodeName = newName;
      }
  
      public final void propagating(final int p) {
          String newName = currentNodeName + "." + p;
  
          if (currentNodeName == null) {
              saveLine(lineTab("\"null\" [label=\"\", shape=point]"));
          }
         final String couleur = estOrange ? "orange" : "green";
 
         saveLine(lineTab("\"" + newName + "\"" + "[label=\""
                 + Integer.toString(p) + "\",shape=point, color=black]"));
         saveLine(lineTab("\"" + currentNodeName + "\"" + " -- " + "\""
                 + newName + "\"" + "[label=" + "\" " + Integer.toString(p)
                 + "\", fontcolor =" + couleur + ", color = " + couleur
                 + ", style = bold]"));
         currentNodeName = newName;
         estOrange = false;
     }
 
     public final void backtracking(final int p) {
         final String temp = pile.last();
         pile.pop();
         saveLine("\"" + temp + "\"" + "--" + "\"" + currentNodeName + "\""
                 + "[label=\"\", color=red, style=dotted]");
         currentNodeName = temp;
     }
 
     public final void adding(final int p) {
         estOrange = true;
     }
 
     public final void learn(final Constr clause) {
     }
 
     public final void delete(final int[] clause) {
     }
 
     public final void conflictFound() {
         saveLine(lineTab("\"" + currentNodeName
                 + "\" [label=\"\", shape=box, color=\"red\", style=filled]"));
     }
 
     public final void solutionFound() {
         saveLine(lineTab("\"" + currentNodeName
                 + "\" [label=\"\", shape=box, color=\"green\", style=filled]"));
     }
 
     public final void beginLoop() {
     }
 
     public final void start() {
         saveLine("graph G {");
     }
 
     public final void end(Lbool result) {
         saveLine("}");
     }
 
     private final String lineTab(final String line) {
         return "\t" + line;
     }
 
     private final void saveLine(final String line) {
         try {
             out.write(line + '\n');
             if ("}".equals(line)) {
                 out.close();
             }
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
     
     private void readObject(ObjectInputStream stream) throws IOException,
             ClassNotFoundException {
         // if the solver is serialized, out is linked to stdout
         stream.defaultReadObject();
         out = new PrintWriter(System.out);
     }
 }