#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2011 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.Data;
using HeuristicLab.Optimization;
using HeuristicLab.Optimization.Operators.LCS;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

namespace HeuristicLab.Encodings.DecisionList {
  [StorableClass]
  [Item("DecisionListSolution", "Represents a DecisionList solution.")]
  public class DecisionListSolution : ResultCollection, IDecisionListSolution {
    private const string ModelResultName = "Model";
    private const string ProblemDataResultName = "ProblemData";
    private const string TrainingAccuracyResultName = "Accuracy (training)";
    private const string TestAccuracyResultName = "Accuracy (test)";
    private const string TrainingNumberOfAliveRulesName = "Number of alive rules (training)";
    private const string TrainingAliveRulesName = "Alive Rules (training)";
    //private const string TestNumberOfAliveRules = "Number of alive rules (test)";
    private const string TrainingTheoryLengthName = "Theory Length (training)";
    private const string TrainingExceptionsLengthName = "Exceptions Length (training)";

    public double TrainingAccuracy {
      get { return ((PercentValue)this[TrainingAccuracyResultName].Value).Value; }
      private set { ((PercentValue)this[TrainingAccuracyResultName].Value).Value = value; }
    }
    public double TestAccuracy {
      get { return ((PercentValue)this[TestAccuracyResultName].Value).Value; }
      private set { ((PercentValue)this[TestAccuracyResultName].Value).Value = value; }
    }
    public int TrainingNumberOfAliveRules {
      get { return ((IntValue)this[TrainingNumberOfAliveRulesName].Value).Value; }
      private set { ((IntValue)this[TrainingNumberOfAliveRulesName].Value).Value = value; }
    }
    public ItemSet<Rule> TrainingAliveRules {
      get { return (ItemSet<Rule>)this[TrainingAliveRulesName].Value; }
      private set { this[TrainingAliveRulesName].Value = value; }
    }
    public double TrainingTheoryLength {
      get { return ((DoubleValue)this[TrainingTheoryLengthName].Value).Value; }
      private set { ((DoubleValue)this[TrainingTheoryLengthName].Value).Value = value; }
    }
    public double TrainingExceptionsLength {
      get { return ((DoubleValue)this[TrainingExceptionsLengthName].Value).Value; }
      private set { ((DoubleValue)this[TrainingExceptionsLengthName].Value).Value = value; }
    }

    public int Classes {
      get { return ProblemData.Classes; }
    }

    IGAssistModel IGAssistSolution.Model {
      get { return Model; }
    }

    public DecisionList Model {
      get { return (DecisionList)this[ModelResultName].Value; ; }
      protected set {
        if (this[ModelResultName].Value != value) {
          if (value != null) {
            this[ModelResultName].Value = value;
            OnModelChanged();
          }
        }
      }
    }

    public IGAssistProblemData ProblemData {
      get { return (IGAssistProblemData)this[ProblemDataResultName].Value; }
      set {
        if (this[ProblemDataResultName].Value != value) {
          if (value != null) {
            ProblemData.Changed -= new EventHandler(ProblemData_Changed);
            this[ProblemDataResultName].Value = value;
            ProblemData.Changed += new EventHandler(ProblemData_Changed);
            OnProblemDataChanged();
          }
        }
      }
    }

    [StorableConstructor]
    protected DecisionListSolution(bool deserializing) : base(deserializing) { }
    protected DecisionListSolution(DecisionListSolution original, Cloner cloner)
      : base(original, cloner) {
      name = original.Name;
      description = original.Description;
    }
    public DecisionListSolution(DecisionList model, IGAssistProblemData problemData)
      : base() {
      name = ItemName;
      description = ItemDescription;
      Add(new Result(ModelResultName, "Decision List.", model));
      Add(new Result(ProblemDataResultName, "The problem data.", problemData));
      Add(new Result(TrainingAccuracyResultName, "Accuracy of the model on the training partition (percentage of correctly classified instances).", new PercentValue()));
      Add(new Result(TestAccuracyResultName, "Accuracy of the model on the test partition (percentage of correctly classified instances).", new PercentValue()));
      Add(new Result(TrainingNumberOfAliveRulesName, "", new IntValue()));
      Add(new Result(TrainingAliveRulesName, "", new ItemSet<Rule>()));
      Add(new Result(TrainingTheoryLengthName, "", new DoubleValue()));
      Add(new Result(TrainingExceptionsLengthName, "", new DoubleValue()));

      problemData.Changed += new EventHandler(ProblemData_Changed);

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

    private void RecalculateResults() {
      var originalTrainingCondition = ProblemData.FetchInput(ProblemData.TrainingIndices);
      var originalTestCondition = ProblemData.FetchInput(ProblemData.TestIndices);
      ItemSet<Rule> aliveRules;
      double theoryLength;
      var estimatedTraining = Model.Evaluate(originalTrainingCondition, out aliveRules, out theoryLength);
      TrainingNumberOfAliveRules = aliveRules.Count + (Model.DefaultAction != null ? 1 : 0);
      TrainingAliveRules = aliveRules;
      TrainingTheoryLength = theoryLength;
      var estimatedTest = Model.Evaluate(originalTestCondition);

      var originalTrainingAction = ProblemData.FetchAction(ProblemData.TrainingIndices);
      var originalTestAction = ProblemData.FetchAction(ProblemData.TestIndices);

      TrainingAccuracy = CalculateAccuracy(originalTrainingAction, estimatedTraining);
      TestAccuracy = CalculateAccuracy(originalTestAction, estimatedTest);

      TrainingExceptionsLength = 105.0 - TrainingAccuracy * 100.0;
    }

    public static double CalculateAccuracy(IEnumerable<IGAssistNiche> original, IEnumerable<IGAssistNiche> estimated) {
      double correctClassified = 0;

      double rows = original.Count();
      var originalEnumerator = original.GetEnumerator();
      var estimatedActionEnumerator = estimated.GetEnumerator();

      while (originalEnumerator.MoveNext() && estimatedActionEnumerator.MoveNext()) {
        if (originalEnumerator.Current != null && estimatedActionEnumerator.Current != null
          && originalEnumerator.Current.SameNiche(estimatedActionEnumerator.Current)) {
          correctClassified++;
        }
      }
      return correctClassified / rows;
    }

    private void ProblemData_Changed(object sender, EventArgs e) {
      OnProblemDataChanged();
    }

    public event EventHandler ModelChanged;
    protected virtual void OnModelChanged() {
      RecalculateResults();
      var listeners = ModelChanged;
      if (listeners != null) listeners(this, EventArgs.Empty);
    }

    public event EventHandler ProblemDataChanged;
    protected virtual void OnProblemDataChanged() {
      RecalculateResults();
      var listeners = ProblemDataChanged;
      if (listeners != null) listeners(this, EventArgs.Empty);
    }

    #region INamedItem Members
    [Storable]
    protected string name;
    public string Name {
      get { return name; }
      set {
        if (!CanChangeName) throw new NotSupportedException("Name cannot be changed.");
        if (!(name.Equals(value) || (value == null) && (name == string.Empty))) {
          CancelEventArgs<string> e = value == null ? new CancelEventArgs<string>(string.Empty) : new CancelEventArgs<string>(value);
          OnNameChanging(e);
          if (!e.Cancel) {
            name = value == null ? string.Empty : value;
            OnNameChanged();
          }
        }
      }
    }
    public virtual bool CanChangeName {
      get { return true; }
    }
    [Storable]
    protected string description;
    public string Description {
      get { return description; }
      set {
        if (!CanChangeDescription) throw new NotSupportedException("Description cannot be changed.");
        if (!(description.Equals(value) || (value == null) && (description == string.Empty))) {
          description = value == null ? string.Empty : value;
          OnDescriptionChanged();
        }
      }
    }
    public virtual bool CanChangeDescription {
      get { return true; }
    }

    public override string ToString() {
      return Name;
    }

    public event EventHandler<CancelEventArgs<string>> NameChanging;
    protected virtual void OnNameChanging(CancelEventArgs<string> e) {
      var handler = NameChanging;
      if (handler != null) handler(this, e);
    }

    public event EventHandler NameChanged;
    protected virtual void OnNameChanged() {
      var handler = NameChanged;
      if (handler != null) handler(this, EventArgs.Empty);
      OnToStringChanged();
    }

    public event EventHandler DescriptionChanged;
    protected virtual void OnDescriptionChanged() {
      var handler = DescriptionChanged;
      if (handler != null) handler(this, EventArgs.Empty);
    }
    #endregion
  }
}