#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;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Encodings.CombinedIntegerVectorEncoding {
  [Item("SinglePointCrossover", "Single point crossover for integer vectors. It is implemented as described in Michalewicz, Z. 1999. Genetic Algorithms + Data Structures = Evolution Programs. Third, Revised and Extended Edition, Spring-Verlag Berlin Heidelberg.")]
  [StorableClass]
  public class SinglePointCrossover : CombinedIntegerVectorCrossover {
    [StorableConstructor]
    protected SinglePointCrossover(bool deserializing) : base(deserializing) { }
    protected SinglePointCrossover(SinglePointCrossover original, Cloner cloner) : base(original, cloner) { }
    public SinglePointCrossover() : base() { }

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

    public static CombinedIntegerVector Apply(IRandom random, CombinedIntegerVector parent1, CombinedIntegerVector parent2) {
      if (parent1.Length != parent2.Length && parent1.ActionLength != parent2.ActionLength && parent1.Bounds.Equals(parent2.Bounds))
        throw new ArgumentException("SinglePointCrossover: The parents are of different length.");

      int length = parent1.Length;
      int actionLength = parent1.ActionLength;
      int conditionLength = length - actionLength;
      int[] result = new int[length];
      int breakPoint = random.Next(1, conditionLength);

      for (int i = 0; i < breakPoint; i++) {
        result[i] = parent1[i];
      }
      for (int i = breakPoint; i < conditionLength; i++) {
        result[i] = parent2[i];
      }

      CombinedIntegerVector actionParent = random.Next(2) == 1 ? parent1 : parent2;
      for (int i = conditionLength; i < length; i++) {
        result[i] = actionParent[i];
      }

      return new CombinedIntegerVector(result, actionLength, parent1.Bounds);
    }

    protected override CombinedIntegerVector Cross(IRandom random, ItemArray<CombinedIntegerVector> parents) {
      if (parents.Length != 2) throw new ArgumentException("ERROR in SinglePointCrossover: The number of parents is not equal to 2");
      return Apply(random, parents[0], parents[1]);
    }
  }
}