#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.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Encodings.VariableVector {
  [StorableClass]
  [Item(Name = "StringVariable", Description = "")]
  public class StringVariable : Variable<string>, IActionVariable {

    public override int VirtualLength {
      get { return 1; }
    }

    [Storable]
    public bool Wildcard { get; set; }

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

    [Storable]
    protected IDictionary<int, string> featureMapping;
    public IDictionary<int, string> FeatureMapping {
      get { return featureMapping; }
    }

    [Storable]
    protected int currentValue;
    public int CurrentValue {
      get { return currentValue; }
      set {
        if (!possibleFeatures.Contains(value)) {
          throw new ArgumentException("Value is not a possible feature of this variable.");
        }
        currentValue = value;
      }
    }

    public string CurrentStringValue {
      get { return featureMapping[currentValue]; }
    }

    [StorableConstructor]
    protected StringVariable(bool deserializing) : base(deserializing) { }
    protected StringVariable(StringVariable original, Cloner cloner)
      : base(original, cloner) {
      this.possibleFeatures = new List<int>(original.possibleFeatures);
      this.featureMapping = new Dictionary<int, string>(original.featureMapping);
      this.Wildcard = original.Wildcard;
      this.currentValue = original.currentValue;
    }
    public StringVariable()
      : base() {
      Wildcard = false;
    }
    public StringVariable(string variableName, IEnumerable<string> variableValues)
      : base(variableName) {
      if (variableValues.Count() != variableValues.Distinct().Count()) {
        throw new ArgumentException("variableValues have to be distinct.");
      }
      featureMapping = new Dictionary<int, string>();
      var distinctValuesEnumerator = variableValues.Distinct().GetEnumerator();
      possibleFeatures = Enumerable.Range(0, variableValues.Count()).ToList();
      var possibleFeaturesEnumerator = possibleFeatures.GetEnumerator();
      while (possibleFeaturesEnumerator.MoveNext() && distinctValuesEnumerator.MoveNext()) {
        featureMapping.Add(possibleFeaturesEnumerator.Current, distinctValuesEnumerator.Current);
      }
      Wildcard = false;
    }
    public StringVariable(string variableName, IEnumerable<string> variableValues, string currentValue)
      : this(variableName, variableValues) {
      int index = 0;
      foreach (var feature in featureMapping) {
        if (feature.Equals(currentValue)) {
          break;
        }
        index++;
      }
      if (index > featureMapping.Count()) { throw new ArgumentException("variableValues do not contain currentValue."); }
      CurrentValue = index;
    }
    public StringVariable(string variableName, IDictionary<int, string> featureMapping)
      : base(variableName) {
      if (featureMapping.Values.Count != featureMapping.Values.Distinct().Count()) {
        throw new ArgumentException("featureMapping values have to be distinct.");
      }
      this.possibleFeatures = featureMapping.Keys.ToList();
      this.featureMapping = featureMapping;
      Wildcard = false;
    }
    public StringVariable(string variableName, IDictionary<int, string> featureMapping, string currentValue)
      : this(variableName, featureMapping) {
      bool found = false;
      foreach (var pair in featureMapping) {
        if (pair.Value.Equals(currentValue)) {
          CurrentValue = pair.Key;
          found = true;
          break;
        }
      }
      if (!found) {
        throw new ArgumentException("variableValues do not contain currentValue.");
      }
    }

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

    public override string ToString() {
      return Wildcard ? "#" : CurrentStringValue;
    }

    public override bool MatchInput(string target) {
      return Wildcard || featureMapping[CurrentValue].Equals(target);
    }

    public override bool Match(string target) {
      return MatchInput(target);
    }

    public override bool MatchVariable(IVariable target) {
      var targetCast = target as StringVariable;
      return targetCast != null && this.variableName.Equals(targetCast.VariableName) && Match(targetCast.CurrentStringValue);
    }

    public override IVariable GetEmptyCopy() {
      return new StringVariable(variableName, featureMapping);
    }
    public override IVariable GetSetCopy() {
      StringVariable copy = (StringVariable)GetEmptyCopy();
      copy.Wildcard = this.Wildcard;
      copy.CurrentValue = this.CurrentValue;
      return copy;
    }
    IActionVariable IActionVariable.GetEmptyCopy() {
      return (StringVariable)GetEmptyCopy();
    }
    IActionVariable IActionVariable.GetSetCopy() {
      return (StringVariable)GetSetCopy();
    }

    public void RandomizeAction(IRandom random) {
      int index = random.Next(possibleFeatures.Count());
      currentValue = possibleFeatures.ElementAt(index);
    }

    public override void Randomize(IRandom random, double changeSymbolProbability) {
      Wildcard = random.NextDouble() < changeSymbolProbability;
      int index = random.Next(possibleFeatures.Count());
      currentValue = possibleFeatures.ElementAt(index);
    }

    public override bool Identical(IVariable target) {
      var targetCast = target as StringVariable;
      if (targetCast == null) { return false; }
      if (variableName != targetCast.variableName || Wildcard != targetCast.Wildcard
        || currentValue != targetCast.currentValue) { return false; }

      var thisEnumerator = featureMapping.GetEnumerator();
      var castEnumerator = targetCast.featureMapping.GetEnumerator();
      while (thisEnumerator.MoveNext() && castEnumerator.MoveNext()) {
        if (thisEnumerator.Current.Key != castEnumerator.Current.Key ||
          thisEnumerator.Current.Value != castEnumerator.Current.Value)
          return false;
      }

      return !thisEnumerator.MoveNext() && !castEnumerator.MoveNext();
    }

    public override double GetGenerality() {
      return Wildcard ? 1 : 0;
    }

    public override bool IsGreaterThanOrEquallyGeneral(IVariable target) {
      var targetCast = target as StringVariable;
      if (targetCast == null) { return false; }
      return Wildcard || (currentValue == targetCast.currentValue && CurrentStringValue.Equals(targetCast.CurrentStringValue));
    }

    public override IVariable CrossParentsAtPosition(IVariable parent2, int pos) {
      var parent2Cast = parent2 as StringVariable;
      if (parent2Cast == null) { throw new ArgumentException("Argument is not of the correct type."); }
      if (pos != 0) { throw new ArgumentOutOfRangeException(); }
      return (StringVariable)parent2.GetSetCopy();
    }

    public override void Manipulate(IRandom random, string stringValue, int pos,
                                    double spreadPercentage) {
      Manipulate(random, stringValue, pos);
    }

    public override void Manipulate(IRandom random, string stringValue, int pos) {
      if (pos != 0) { throw new ArgumentOutOfRangeException(); }
      Wildcard = !Wildcard;
      if (!Wildcard) {
        currentValue = featureMapping.First(x => x.Value.Equals(stringValue)).Key;
      }
    }

    public override void Cover(IRandom random, string stringValue, double changeSymbolProbability) {
      Wildcard = random.NextDouble() < changeSymbolProbability;
      if (!Wildcard) {
        currentValue = featureMapping.First(x => x.Value.Equals(stringValue)).Key;
      }
    }

    public override int GetHashCode() {
      int result = 1;
      int wildcardInt = Wildcard ? 1 : 0;
      result = 37 * result + wildcardInt;
      result = 37 * result + currentValue;
      foreach (var feature in featureMapping) {
        result = 37 * result + feature.Key;
        result = 37 * result + feature.Value.GetHashCode();
      }
      return result;
    }

    #region IActionVariable Members
    public void SetTo(string value) {
      currentValue = featureMapping.First(x => x.Value.Equals(value)).Key;
    }

    public IEnumerable<string> GetAllPossibleActions() {
      return featureMapping.Values;
    }
    #endregion
  }
}