#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 HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Encodings.IntegerVectorEncoding;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Random;
using HEAL.Attic;

namespace HeuristicLab.Problems.GeneralizedQuadraticAssignment {
  [Item("Exhaustive 1-Move MoveGenerator", "Exhaustively generates all possible 1-moves.")]
  [StorableType("A200C3BE-D761-4F82-9CA9-44A7BB2AB0DD")]
  public class ExhaustiveOneMoveGenerator : GQAPNMoveGenerator, IStochasticOperator, IExhaustiveMoveGenerator {
    
    public ILookupParameter<IRandom> RandomParameter {
      get { return (ILookupParameter<IRandom>)Parameters["Random"]; }
    }

    [StorableConstructor]
    protected ExhaustiveOneMoveGenerator(StorableConstructorFlag _) : base(_) { }
    protected ExhaustiveOneMoveGenerator(ExhaustiveOneMoveGenerator original, Cloner cloner) : base(original, cloner) { }
    public ExhaustiveOneMoveGenerator()
      : base() {
      Parameters.Add(new LookupParameter<IRandom>("Random", "The random number generator that should be used."));
      NParameter.Value.Value = 1;
      NParameter.Hidden = true;
    }

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

    public static IEnumerable<NMove> Generate(IntegerVector assignment, GQAPInstance problemInstance) {
      var equipments = problemInstance.Demands.Length;
      var locations = problemInstance.Capacities.Length;
      var tmp = new int[equipments];
      for (var e = 0; e < equipments; e++) {
        var indices = new List<int> { e };
        for (var l = 0; l < locations; l++) {
          if (assignment[e] == l) continue;
          var reassign = (int[])tmp.Clone();
          reassign[e] = l + 1;
          yield return new NMove(reassign, indices);
        }
      }
    }

    public static IEnumerable<NMove> GenerateAllNxM(GQAPInstance problemInstance) {
      var equipments = problemInstance.Demands.Length;
      var locations = problemInstance.Capacities.Length;
      var tmp = new int[equipments];
      for (var e = 0; e < equipments; e++) {
        var indices = new List<int> { e };
        for (var l = 0; l < locations; l++) {
          var reassign = (int[])tmp.Clone();
          reassign[e] = l + 1;
          yield return new NMove(reassign, indices);
        }
      }
    }

    public override IEnumerable<NMove> GenerateMoves(IntegerVector assignment, int n, GQAPInstance problemInstance) {
      if (n != 1) throw new ArgumentException("N must be equal to 1 for the exhaustive 1-move generator.");
      var random = RandomParameter.ActualValue;
      return Generate(assignment, problemInstance).Shuffle(random);
    }
  }
}