#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2010 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.Encodings.RealVectorEncoding;
using HeuristicLab.Parameters;
using HEAL.Attic;

namespace HeuristicLab.Analysis.FitnessLandscape {

  [Item("RealVectorFitnessDistanceCorrelationAnalyzer", "An operator that analyzes the correlation between fitness and distance to the best know solution for real vector encoding")]
  [StorableType("84EA2C55-F847-4CF9-B966-0E7B9DD8903C")]
  public class RealVectorFitnessDistanceCorrelationAnalyzer : FitnessDistanceCorrelationAnalyzer, IRealVectorOperator {

    #region Parameters
    public ScopeTreeLookupParameter<RealVector> RealVectorParameter {
      get { return (ScopeTreeLookupParameter<RealVector>)Parameters["RealVector"]; }
    }
    public LookupParameter<RealVector> BestKnownSolution {
      get { return (LookupParameter<RealVector>)Parameters["BestKnownSolution"]; }
    }
    #endregion

    [StorableConstructor]
    protected RealVectorFitnessDistanceCorrelationAnalyzer(StorableConstructorFlag _) : base(_) { }
    protected RealVectorFitnessDistanceCorrelationAnalyzer(RealVectorFitnessDistanceCorrelationAnalyzer original, Cloner cloner) : base(original, cloner) { }

    public RealVectorFitnessDistanceCorrelationAnalyzer() {
      Parameters.Add(new ScopeTreeLookupParameter<RealVector>("RealVector", "The real encoded solution"));
      Parameters.Add(new LookupParameter<RealVector>("BestKnownSolution", "The best known solution"));
      RealVectorParameter.ActualName = "Point";
    }

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

    public static double Distance(RealVector a, RealVector b) {
      if (a.Length != b.Length)
        throw new InvalidOperationException("Cannot compare vectors of different lengths");
      double sum = 0;
      for (int i = 0; i < a.Length; i++) {
        sum += (a[i] - b[i]) * (a[i] - b[i]);
      }
      return Math.Sqrt(sum);
    }

    protected override IEnumerable<double> GetDistancesToBestKnownSolution() {
      if (this.RealVectorParameter.ActualValue == null)
        return new double[0];
      RealVector bestKnownValue = BestKnownSolution.ActualValue;
      if (bestKnownValue == null)
        return RealVectorParameter.ActualValue.Select(v => 0d);
      return RealVectorParameter.ActualValue.Select(v => Distance(v, bestKnownValue));
    }
  }
}