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

namespace HeuristicLab.Encodings.LinearLinkageEncoding {
  [Item("Split Move", "Splits a group into two groups.")]
  [StorableClass]
  public sealed class SplitMove : EMSSMove {
    [Storable]
    private int nextItem; // is only used for undo -> no public property

    [StorableConstructor]
    private SplitMove(bool deserializing) : base(deserializing) { }
    private SplitMove(SplitMove original, Cloner cloner)
      : base(original, cloner) {
      nextItem = original.nextItem;
    }
    public SplitMove(int item)
      : base(item) {
      nextItem = -1;
    }
    
    public override IDeepCloneable Clone(Cloner cloner) {
      return new SplitMove(this, cloner);
    }

    public override void Apply(LinearLinkage lle) {
      if (lle[Item] == Item) throw new ArgumentException("Move conditions have changed, group is already split at " + Item);
      nextItem = lle[Item];
      lle[Item] = Item;
    }

    public override void Undo(LinearLinkage lle) {
      if (lle[Item] != Item) throw new ArgumentException("Move conditions have changed, group no longer terminates at " + Item);
      if (nextItem < 0) throw new InvalidOperationException("Cannot undo move that has not been applied first.");
      lle[Item] = nextItem;
    }

    public override void ApplyToLLEb(int[] lleb) {
      if (nextItem < 0) throw new InvalidOperationException("Cannot undo move that has not been applied first to LLE.");
      lleb[nextItem] = nextItem;
    }
  }
}