using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Operators;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Problems.MetaOptimization {
  /// <summary>
  /// TODO 
  /// </summary>
  [Item("PMOBestSolutionHistoryAnalyzer", "")]
  [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<ConstrainedItemList<IProblem>> ProblemsParameter {
      get { return (LookupParameter<ConstrainedItemList<IProblem>>)Parameters[MetaOptimizationProblem.ProblemsParameterName]; }
    }
    public LookupParameter<IntValue> GenerationsParameter {
      get { return (LookupParameter<IntValue>)Parameters["Generations"]; }
    }
    public LookupParameter<BoolValue> MaximizationParameter {
      get { return (LookupParameter<BoolValue>)Parameters["Maximization"]; }
    }

    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<ConstrainedItemList<IProblem>>(MetaOptimizationProblem.ProblemsParameterName));
      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);
    }

    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();
    }
  }
}