#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2018 Heuristic and Evolutionary Algorithms Laboratory (HEAL)
 *
 * This file is part of HeuristicLab.
 *
 * HeuristicLab is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * HeuristicLab 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with HeuristicLab. If not, see <http://www.gnu.org/licenses/>.
 */
#endregion

using System;
using System.Diagnostics;
using System.IO;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Algorithms.DataAnalysis.SymRegGrammarEnumeration {
  [Item("SearchGraphVisualizer", "")]
  [StorableClass]
  internal class SearchGraphVisualizer : Item, IGrammarEnumerationAnalyzer {
    private readonly string dotFileName = Environment.GetFolderPath(Environment.SpecialFolder.DesktopDirectory) + @"\searchgraph.dot";

    private TextWriterTraceListener dotFileTrace;

    public SearchGraphVisualizer() { }

    protected SearchGraphVisualizer(SearchGraphVisualizer original, Cloner cloner) : base(original, cloner) { }

    [StorableConstructor]
    protected SearchGraphVisualizer(bool deserializing) : base(deserializing) { }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new SearchGraphVisualizer(this, cloner);
    }

    public void Register(GrammarEnumerationAlgorithm algorithm) {
      algorithm.Started += GrammarEnumerationAlgorithmOnStarted;
      algorithm.Stopped += GrammarEnumerationAlgorithmOnStopped;
      algorithm.ExceptionOccurred += GrammarEnumerationAlgorithmOnStopped;

      algorithm.PhraseFetched += PhraseFetched;
      algorithm.PhraseDerived += PhraseDerived;
      algorithm.SentenceGenerated += SentenceGenerated;
    }

    public void Deregister(GrammarEnumerationAlgorithm algorithm) {
      algorithm.Started -= GrammarEnumerationAlgorithmOnStarted;
      algorithm.Stopped -= GrammarEnumerationAlgorithmOnStopped;
      algorithm.ExceptionOccurred -= GrammarEnumerationAlgorithmOnStopped;

      algorithm.PhraseFetched -= PhraseFetched;
      algorithm.PhraseDerived -= PhraseDerived;
      algorithm.SentenceGenerated -= SentenceGenerated;
    }

    private void GrammarEnumerationAlgorithmOnStarted(object sender, EventArgs eventArgs) {
      dotFileTrace = new TextWriterTraceListener(new FileStream(dotFileName, FileMode.Create));
      ((StreamWriter)dotFileTrace.Writer).AutoFlush = true;
      dotFileTrace.WriteLine("digraph searchgraph { pad=0.02; nodesep=0.3; ranksep=0.02;ratio=0.5625;");
    }

    private void GrammarEnumerationAlgorithmOnStopped(object sender, EventArgs eventArgs) {
      try {
        var alg = (GrammarEnumerationAlgorithm)sender;
        var phrase0 = new SymbolList(new[] { alg.Grammar.StartSymbol });
        var phrase0Hash = alg.Grammar.Hasher.CalcHashCode(phrase0);

        dotFileTrace.WriteLine($"{phrase0Hash} [label=\"{phrase0}\", shape=doublecircle]; }}");
        dotFileTrace.Flush();
      } catch (Exception) {
        dotFileTrace.Close();
        throw;
      }
    }

    private void PhraseFetched(object sender, PhraseEventArgs phraseEventArgs) {
      dotFileTrace.WriteLine($"{phraseEventArgs.Hash} [label=\"{phraseEventArgs.Phrase}\"];");
    }

    private void PhraseDerived(object sender, PhraseAddedEventArgs args) {
      dotFileTrace.WriteLine($"{args.ParentHash} -> {args.NewHash} [label=\"{args.ExpandedSymbol.StringRepresentation} + &rarr; {args.ExpandedProduction}\"];");
    }

    private void SentenceGenerated(object sender, PhraseAddedEventArgs args) {
      var alg = (GrammarEnumerationAlgorithm)sender;
      dotFileTrace.WriteLine($"{args.NewHash} [label=\"{alg.Grammar.ToInfixString(args.NewPhrase)}\", style=\"filled\", fillcolor=\"#f79423\", color=\"#f79423\"];");
    }
  }
}