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

namespace HeuristicLab.Encodings.ConditionActionEncoding {
  [StorableClass]
  [Item("ConditionActionEnsembleModel", "")]
  public class ConditionActionEnsembleModel : NamedItem, IConditionActionEnsembleModel {

    [Storable]
    private List<IConditionActionModel> models;
    public IEnumerable<IConditionActionModel> Models {
      get { return new List<IConditionActionModel>(models); }
    }

    [Storable]
    private IClassifierComparer comparer;
    public IClassifierComparer ClassifierComparer {
      get { return comparer; }
      set { comparer = value; }
    }

    [StorableConstructor]
    protected ConditionActionEnsembleModel(bool deserializing) : base(deserializing) { }
    protected ConditionActionEnsembleModel(ConditionActionEnsembleModel original, Cloner cloner)
      : base(original, cloner) {
      this.models = original.Models.Select(m => cloner.Clone(m)).ToList();
    }
    public ConditionActionEnsembleModel() : this(Enumerable.Empty<IConditionActionModel>()) { }
    public ConditionActionEnsembleModel(IEnumerable<IConditionActionModel> models)
      : base() {
      this.name = ItemName;
      this.description = ItemDescription;
      this.models = new List<IConditionActionModel>(models);
    }
    public override IDeepCloneable Clone(Cloner cloner) {
      return new ConditionActionEnsembleModel(this, cloner);
    }

    public void Add(IConditionActionModel model) {
      models.Add(model);
    }
    public void Remove(IConditionActionModel model) {
      models.Remove(model);
    }

    public IEnumerable<IEnumerable<IAction>> GetEstimatedActionVectors(IEnumerable<IInput> input) {
      var estimatedValuesEnumerators = (from model in models
                                        select model.GetAction(input).GetEnumerator())
                                       .ToList();

      while (estimatedValuesEnumerators.All(en => en.MoveNext())) {
        yield return from enumerator in estimatedValuesEnumerators
                     select enumerator.Current;
      }
    }

    public IEnumerable<IAction> GetAction(IEnumerable<IInput> input) {
      foreach (var estimatedValuesVector in GetEstimatedActionVectors(input)) {
        // return the class which is most often occuring
        yield return
          estimatedValuesVector
          .GroupBy(x => x, comparer)
          .OrderByDescending(g => g.Count())
          .Select(g => g.Key)
          .First();
      }
    }

    public IAction GetAction(IInput classifier) {
      var estimatedValuesVector = models.Select(x => x.GetAction(classifier));
      return estimatedValuesVector
           .GroupBy(x => x, comparer)
           .OrderByDescending(g => g.Count())
           .Select(g => g.Key)
           .First();
    }

    public IConditionActionSolution CreateConditionActionSolution(IConditionActionProblemData problemData) {
      return new ConditionActionEnsembleSolution(models, new ConditionActionEnsembleProblemData((IConditionActionProblemData)problemData.Clone()));
    }

    public int ClassifierCount {
      get { return Models.Sum(x => x.ClassifierCount); }
    }
  }
}