#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.Collections.Generic;
using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Problems.TestFunctions.MultiObjective {
  [StorableClass]
  [Item("HypervolumeAnalyzer", "This analyzer is functionally equivalent to the HypervolumeAnalyzer in HeuristicLab.Analysis, but is kept as not to break backwards compatibility")]
  public class HypervolumeAnalyzer : MOTFAnalyzer {

    public ILookupParameter<DoubleArray> ReferencePointParameter => (ILookupParameter<DoubleArray>)Parameters["ReferencePoint"];

    public IResultParameter<DoubleValue> HypervolumeResultParameter => (IResultParameter<DoubleValue>)Parameters["Hypervolume"];

    public IResultParameter<DoubleValue> BestKnownHypervolumeResultParameter => (IResultParameter<DoubleValue>)Parameters["Best known hypervolume"];

    public IResultParameter<DoubleValue> HypervolumeDistanceResultParameter => (IResultParameter<DoubleValue>)Parameters["Absolute Distance to BestKnownHypervolume"];


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

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

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

    public HypervolumeAnalyzer() {
      Parameters.Add(new LookupParameter<DoubleArray>("ReferencePoint", "The reference point for hypervolume calculation"));
      Parameters.Add(new ResultParameter<DoubleValue>("Hypervolume", "The hypervolume of the current generation"));
      Parameters.Add(new ResultParameter<DoubleValue>("Best known hypervolume", "The optimal hypervolume"));
      Parameters.Add(new ResultParameter<DoubleValue>("Absolute Distance to BestKnownHypervolume", "The difference between the best known and the current hypervolume"));
      HypervolumeResultParameter.DefaultValue = new DoubleValue(0);
      BestKnownHypervolumeResultParameter.DefaultValue = new DoubleValue(0);
      HypervolumeDistanceResultParameter.DefaultValue = new DoubleValue(0);
    }

    public override IOperation Apply() {
      var qualities = QualitiesParameter.ActualValue;
      var testFunction = TestFunctionParameter.ActualValue;
      var objectives = qualities[0].Length;
      var referencePoint = ReferencePointParameter.ActualValue;

      var best = BestKnownHypervolumeResultParameter.ActualValue.Value;
      if (referencePoint.SequenceEqual(testFunction.ReferencePoint(objectives))) {
        best = Math.Max(best, testFunction.OptimalHypervolume(objectives));
      }

      var hv = HypervolumeCalculator.CalculateHypervolume(qualities.Select(x=>x.CloneAsArray()).ToArray(), referencePoint.ToArray(), testFunction.Maximization(objectives));

      if (hv > best) {
        best = hv;
      }

      HypervolumeResultParameter.ActualValue.Value = hv;
      BestKnownHypervolumeResultParameter.ActualValue.Value = best;
      HypervolumeDistanceResultParameter.ActualValue.Value = best - hv;

      return base.Apply();
    }

  }
}