#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2012 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.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Encodings.ParameterConfigurationEncoding;
using HeuristicLab.Operators;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Problems.MetaOptimization {
  /// <summary>
  /// An analyzer that tracks the history of best parameter configurations.
  /// </summary>
  [Item("PMOBestSolutionHistoryAnalyzer", "An analyzer that tracks the history of best solutions.")]
  [StorableClass]
  public sealed class PMOBestSolutionHistoryAnalyzer : SingleSuccessorOperator, IAnalyzer {
    public bool EnabledByDefault {
      get { return true; }
    }

    public ScopeTreeLookupParameter<ParameterConfigurationTree> ParameterConfigurationParameter {
      get { return (ScopeTreeLookupParameter<ParameterConfigurationTree>)Parameters["ParameterConfigurationTree"]; }
    }
    public ScopeTreeLookupParameter<DoubleValue> QualityParameter {
      get { return (ScopeTreeLookupParameter<DoubleValue>)Parameters["Quality"]; }
    }
    public ValueLookupParameter<ResultCollection> ResultsParameter {
      get { return (ValueLookupParameter<ResultCollection>)Parameters["Results"]; }
    }
    public LookupParameter<IntValue> GenerationsParameter {
      get { return (LookupParameter<IntValue>)Parameters["Generations"]; }
    }
    public LookupParameter<BoolValue> MaximizationParameter {
      get { return (LookupParameter<BoolValue>)Parameters["Maximization"]; }
    }

    #region Constructors and Cloning
    public PMOBestSolutionHistoryAnalyzer()
      : base() {
      Parameters.Add(new ScopeTreeLookupParameter<ParameterConfigurationTree>("ParameterConfigurationTree", ""));
      Parameters.Add(new ScopeTreeLookupParameter<DoubleValue>("Quality", ""));
      Parameters.Add(new ValueLookupParameter<ResultCollection>("Results", ""));
      Parameters.Add(new LookupParameter<IntValue>("Generations", ""));
      Parameters.Add(new LookupParameter<BoolValue>("Maximization", "Set to false if the problem should be minimized."));
    }

    [StorableConstructor]
    private PMOBestSolutionHistoryAnalyzer(bool deserializing) : base(deserializing) { }
    private PMOBestSolutionHistoryAnalyzer(PMOBestSolutionHistoryAnalyzer original, Cloner cloner) : base(original, cloner) { }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new PMOBestSolutionHistoryAnalyzer(this, cloner);
    }
    #endregion

    public override IOperation Apply() {
      ItemArray<DoubleValue> qualities = QualityParameter.ActualValue;
      ResultCollection results = ResultsParameter.ActualValue;
      ItemArray<ParameterConfigurationTree> parameterTrees = ParameterConfigurationParameter.ActualValue;
      int currentGeneration = GenerationsParameter.ActualValue.Value;
      bool maximization = MaximizationParameter.ActualValue.Value;

      int idxBest;
      if (maximization)
        idxBest = qualities.Select((x, index) => new { index, x.Value }).OrderBy(x => x.Value).Last().index;
      else
        idxBest = qualities.Select((x, index) => new { index, x.Value }).OrderBy(x => x.Value).First().index;

      ParameterConfigurationTree best = parameterTrees[idxBest];

      string key = "BestSolutionHistory";
      RunCollection bestSolutionHistory;
      if (!results.ContainsKey(key)) {
        bestSolutionHistory = new RunCollection();
        results.Add(new Result(key, bestSolutionHistory));
      } else {
        bestSolutionHistory = results[key].Value as RunCollection;
      }
      if (bestSolutionHistory.Count == 0 || best.ParameterInfoString != ((StringValue)bestSolutionHistory.Last().Results["Meta-ParameterInfoString"]).Value) {
        IRun run = best.ToRun(string.Format("{0}: {1}", currentGeneration, best.ParameterInfoString), false);
        run.Results.Add("Meta-Generation", new IntValue(currentGeneration));
        run.Results.Add("Meta-ParameterInfoString", new StringValue(best.ParameterInfoString));
        bestSolutionHistory.Add(run);
      }

      return base.Apply();
    }
  }
}