// ========================================================================
   // Copyright (c) Webtide LLC
   // ------------------------------------------------------------------------
   // All rights reserved. This program and the accompanying materials
   // are made available under the terms of the Eclipse Public License v1.0
   // and Apache License v2.0 which accompanies this distribution.
   //
   // The Eclipse Public License is available at 
   // http://www.eclipse.org/legal/epl-v10.html
  //
  // The Apache License v2.0 is available at
  // http://www.apache.org/licenses/LICENSE-2.0.txt
  //
  // You may elect to redistribute this code under either of these licenses. 
  // ========================================================================
  package org.eclipse.jetty.deploy.graph;
  
  import java.io.File;
  import java.io.FileWriter;
  import java.io.IOException;
  import java.io.PrintWriter;
  import java.text.CollationKey;
  import java.text.Collator;
  import java.util.Comparator;
  import java.util.Set;
  import java.util.TreeSet;
  
  import org.eclipse.jetty.util.IO;
  
  /**
   * Output the Graph in GraphViz Dot format.
   */
  public class GraphOutputDot
  {
      private GraphOutputDot()
      {
      }
  
      private static final String TOPNODE = "undeployed";
  
      /**
       * Comparator that makes the 'undeployed' node the first node in the sort list.
       * 
       * This makes the 'undeployed' node show up at the top of the generated graph.
       */
      private static class TopNodeSort implements Comparator<Node>
      {
          private Collator collator = Collator.getInstance();
  
          public int compare(Node o1, Node o2)
          {
              if (o1.getName().equals(TOPNODE))
              {
                  return -1;
              }
  
              if (o2.getName().equals(TOPNODE))
              {
                  return 1;
              }
  
              CollationKey key1 = toKey(o1);
              CollationKey key2 = toKey(o2);
              return key1.compareTo(key2);
          }
  
          private CollationKey toKey(Node node)
          {
              return collator.getCollationKey(node.getName());
          }
      }
  
      public static void write(Graph graph, File outputFile) throws IOException
      {
          FileWriter writer = null;
          PrintWriter out = null;
  
          try
          {
              writer = new FileWriter(outputFile);
              out = new PrintWriter(writer);
  
              out.println("// Autogenerated by " + GraphOutputDot.class.getName());
              out.println("digraph Graf {");
  
              writeGraphDefaults(out);
              writeNodeDefaults(out);
              writeEdgeDefaults(out);
  
              Set<Node> nodes = new TreeSet<Node>(new TopNodeSort());
              nodes.addAll(graph.getNodes());
  
              for (Node node : nodes)
              {
                  writeNode(out,node);
              }
  
              for (Edge edge : graph.getEdges())
              {
                 writeEdge(out,edge);
             }
 
             out.println("}");
         }
         finally
         {
             IO.close(out);
             IO.close(writer);
         }
     }
 
     private static void writeEdge(PrintWriter out, Edge edge)
     {
         out.println();
         out.println("  // Edge");
         out.printf("  \"%s\" -> \"%s\" [%n",toId(edge.getFrom()),toId(edge.getTo()));
         out.println("    arrowtail=none,");
         out.println("    arrowhead=normal");
         out.println("  ];");
     }
 
     private static void writeNode(PrintWriter out, Node node)
     {
         out.println();
         out.println("  // Node");
         out.printf("  \"%s\" [%n",toId(node));
         out.printf("    label=\"%s\",%n",node.getName());
         if (node.getName().endsWith("ed"))
         {
             out.println("    color=\"#ddddff\",");
             out.println("    style=filled,");
         }
         out.println("    shape=box");
         out.println("  ];");
     }
 
     private static CharSequence toId(Node node)
     {
         StringBuilder buf = new StringBuilder();
 
         for (char c : node.getName().toCharArray())
         {
             if (Character.isLetter(c))
             {
                 buf.append(c);
                 continue;
             }
 
             if (Character.isDigit(c))
             {
                 buf.append(c);
                 continue;
             }
 
             if ((c == ' ') || (c == '-') || (c == '_'))
             {
                 buf.append(c);
                 continue;
             }
         }
 
         return buf;
     }
 
     private static void writeEdgeDefaults(PrintWriter out)
     {
         out.println();
         out.println("  // Edge Defaults ");
         out.println("  edge [");
         out.println("    arrowsize=\"0.8\",");
         out.println("    fontsize=\"11\"");
         out.println("  ];");
     }
 
     private static void writeGraphDefaults(PrintWriter out)
     {
         out.println();
         out.println("  // Graph Defaults ");
         out.println("  graph [");
         out.println("    bgcolor=\"#ffffff\",");
         out.println("    fontname=\"Helvetica\",");
         out.println("    fontsize=\"11\",");
         out.println("    label=\"Graph\",");
         out.println("    labeljust=\"l\",");
         out.println("    rankdir=\"TD\"");
         out.println("  ];");
     }
 
     private static void writeNodeDefaults(PrintWriter out)
     {
         out.println();
         out.println("  // Node Defaults ");
         out.println("  node [");
         out.println("    fontname=\"Helvetica\",");
         out.println("    fontsize=\"11\",");
         out.println("    shap=\"box\"");
         out.println("  ];");
     }
 }