#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 System.Collections.Generic;
using System.Linq;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Optimization.Operators.LCS;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Encodings.DecisionList {
  [StorableClass]
  [Item("StringAction", "")]
  public class StringAction : Item, IAction<string> {

    public static IEqualityComparer<IGAssistNiche> Comparer {
      get { return new GAssistNicheComparer(); }
    }

    IEqualityComparer<IGAssistNiche> IGAssistNiche.Comparer {
      get { return Comparer; }
    }

    [Storable]
    protected string variableName;
    public string VariableName {
      get { return variableName; }
    }

    [Storable]
    protected IList<string> possibleFeatures;
    public IEnumerable<string> PossibleFeatures {
      get { return possibleFeatures; }
    }

    [Storable]
    protected int currentActionIndex;
    public int CurrentActionIndex {
      get { return currentActionIndex; }
    }

    public int CurrentPosition {
      get { return CurrentActionIndex; }
    }

    public string CurrentAction {
      get { return possibleFeatures[currentActionIndex]; }
    }

    public int Possibilities { get { return possibleFeatures.Count; } }

    [StorableConstructor]
    protected StringAction(bool deserializing) : base(deserializing) { }
    protected StringAction(StringAction original, Cloner cloner)
      : base(original, cloner) {
      variableName = original.variableName;
      possibleFeatures = new List<string>(original.possibleFeatures);
      currentActionIndex = original.currentActionIndex;
    }
    public StringAction(string variableName, IList<string> variableValues)
      : base() {
      if (variableValues.Count() > 0 && variableValues.Count() != variableValues.Distinct().Count()) {
        throw new ArgumentException("variableValues have to be distinct and there has to be at least one value.");
      }
      this.possibleFeatures = variableValues;
      this.variableName = variableName;
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new StringAction(this, cloner);
    }

    public IEnumerable<int> GetPossibleActionPositions() {
      return Enumerable.Range(0, possibleFeatures.Count);
    }

    public IEnumerable<string> GetPossibleActions() {
      return PossibleFeatures;
    }

    public void Randomize(IRandom random) {
      currentActionIndex = random.Next(0, possibleFeatures.Count());
    }

    public void Randomize(IRandom random, IEnumerable<IAction> except) {
      if (except.Count() == 0) {
        Randomize(random);
        return;
      }
      try {
        var exceptInt = except.Cast<StringAction>().Select(x => x.CurrentActionIndex);
        var newPossibleFeatures = Enumerable.Range(0, possibleFeatures.Count()).Except(exceptInt);
        currentActionIndex = newPossibleFeatures.ElementAt(random.Next(0, newPossibleFeatures.Count()));
      }
      catch (InvalidCastException) {
        throw new InvalidCastException("Actions have to be of type IntAction");
      }
    }

    public bool Match(IAction action) {
      var targetCast = action as StringAction;
      return targetCast != null && this.variableName.Equals(targetCast.VariableName) && CurrentAction.Equals(targetCast.CurrentAction);
    }

    public void SetTo(string value) {
      SetToPosition(possibleFeatures.IndexOf(value));
    }

    public void SetTo(IGAssistNiche action) {
      var castAction = action as StringAction;
      if (castAction == null) throw new ArgumentException("action has to be IntAction");
      SetToPosition(castAction.CurrentPosition);
    }

    public void SetToPosition(int value) {
      if (value < 0 || value > possibleFeatures.Count) { throw new ArgumentOutOfRangeException(); }
      currentActionIndex = value;
    }

    public override string ToString() {
      return variableName + ": " + CurrentAction;
    }

    public bool SameNiche(IGAssistNiche niche) {
      return Match(niche as IAction);
    }

    public int GetNicheHashCode() {
      int result = 1;
      result = 37 * result + currentActionIndex;
      result = 37 * result + variableName.GetHashCode();
      foreach (var feature in possibleFeatures) {
        result = 37 * result + feature.GetHashCode();
      }
      return result;
    }
  }
}