#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2015 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.Operators;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Random;

namespace HeuristicLab.Algorithms.ALPS.SteadyState {
  [Item("AlpsSsMover", "")]
  [StorableClass]
  public class AlpsSsMover : SingleSuccessorOperator, IStochasticOperator {
    private ILookupParameter<IntValue> LayerParameter {
      get { return (ILookupParameter<IntValue>)Parameters["Layer"]; }
    }
    private ILookupParameter<IntValue> TargetIndexParameter {
      get { return (ILookupParameter<IntValue>)Parameters["TargetIndex"]; }
    }
    private ILookupParameter<IntValue> PopulationSizeParameter {
      get { return (ILookupParameter<IntValue>)Parameters["PopulationSize"]; }
    }
    private ILookupParameter<IntValue> NumberOfLayersParameter {
      get { return (ILookupParameter<IntValue>)Parameters["NumberOfLayers"]; }
    }
    private ILookupParameter<IScope> WorkingScopeParameter {
      get { return (ILookupParameter<IScope>)Parameters["WorkingScope"]; }
    }
    private ILookupParameter<IScope> LayersParameter {
      get { return (ILookupParameter<IScope>)Parameters["Layers"]; }
    }
    public ILookupParameter<IRandom> RandomParameter {
      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
    }

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

    public AlpsSsMover()
      : base() {
      Parameters.Add(new LookupParameter<IntValue>("Layer"));
      Parameters.Add(new LookupParameter<IntValue>("TargetIndex"));
      Parameters.Add(new LookupParameter<IntValue>("PopulationSize"));
      Parameters.Add(new LookupParameter<IntValue>("NumberOfLayers"));
      Parameters.Add(new LookupParameter<IScope>("WorkingScope"));
      Parameters.Add(new LookupParameter<IScope>("Layers"));
      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator to use."));
    }

    private int n;
    private int m;
    private IScope layers;
    private IRandom rand;
    public override IOperation Apply() {
      int i = LayerParameter.ActualValue.Value;
      int j = TargetIndexParameter.ActualValue.Value;
      n = NumberOfLayersParameter.ActualValue.Value;
      m = PopulationSizeParameter.ActualValue.Value;
      rand = RandomParameter.ActualValue;

      layers = LayersParameter.ActualValue;
      var newIndividual = (IScope)WorkingScopeParameter.ActualValue.Clone();
      newIndividual.Name = j.ToString();

      TryMoveUp(i, j);
      var currentLayer = layers.SubScopes[i];
      currentLayer.SubScopes[j] = newIndividual;

      return base.Apply();
    }
    private void TryMoveUp(int i, int j) {
      var currentLayer = layers.SubScopes[i];
      var currentIndividual = currentLayer.SubScopes[j];
      if (i < n - 1) {
        var nextLayer = layers.SubScopes[i + 1];
        int? k = FindReplaceable(nextLayer, currentIndividual);

        if (k.HasValue) {
          TryMoveUp(i + 1, k.Value);
          nextLayer.SubScopes[k.Value] = currentIndividual;
        }
      }
    }
    private int? FindReplaceable(IScope layer, IScope individual) {
      return Enumerable.Range(0, layer.SubScopes.Count).SampleRandom(rand);
    }
  }
}