#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 System.Linq;
using HEAL.Attic;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Optimization;

namespace HeuristicLab.Problems.Modifiers {
  [StorableType("D5B5D05B-FBF5-434F-AB25-E382D83FAA0B")]
  [Item("MultiObjectiveEndPointProblemModifier", "A dummy problem modifier leading to a multi-objective basic problem")]
  public class MultiObjectiveEndPointProblemModifier<T> : ProblemModifier where T : class, IEncoding {

    private MultiObjectiveBasicProblem<T> problem;
    [Storable]
    public MultiObjectiveBasicProblem<T> Problem {
      get => problem;
      set {
        if (problem == value) return;
        if (problem != null) {
          problem.SolutionCreatorChanged -= OnUpdateRequired;
          if (problem.Encoding?.Parameters != null) {
            foreach (var encodingParameter in problem.Encoding.Parameters.OfType<IValueParameter>())
              encodingParameter.ValueChanged -= OnParameterValueChanged;
          }
        }
        problem = value;
        UpdateState();
        try { //this is to catch inconsistent states during deserialization
          var enc = problem.Encoding.Parameters;
        } catch (NullReferenceException) {
          return;
        }
        problem.SolutionCreatorChanged += OnUpdateRequired;
        if (problem.Encoding?.Parameters == null) return;
        foreach (var encodingParameter in problem.Encoding.Parameters.OfType<IValueParameter>())
          encodingParameter.ValueChanged += OnParameterValueChanged;
      }
    }

    private void OnUpdateRequired(object o, EventArgs e) {
      UpdateState();
    }
    private void OnParameterValueChanged(object o, EventArgs e) {
      UpdateState();
      ((IValueParameter)o).Value.ToStringChanged += OnUpdateRequired;
    }

    public override IEncoding Encoding => Problem?.Encoding;
    public override BoolArray Maximization {
      get {
        if (Problem == null) return new BoolArray(new[] { false, false });
        var dict = new Dictionary<string, IItem>();
        Problem.CollectParameterValues(dict);
        return dict.ContainsKey("Maximization") ? (BoolArray)dict["Maximization"] : new BoolArray(problem.Maximization);
      }
    }

    #region constructors and cloning
    public override ISolutionCreator SolutionCreator => Problem?.SolutionCreator;

    [StorableConstructor]
    protected MultiObjectiveEndPointProblemModifier(StorableConstructorFlag _) : base(_) { }
    protected MultiObjectiveEndPointProblemModifier(MultiObjectiveEndPointProblemModifier<T> original, Cloner cloner) : base(original, cloner) {
      Problem = cloner.Clone(original?.Problem);
    }
    public MultiObjectiveEndPointProblemModifier() { }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new MultiObjectiveEndPointProblemModifier<T>(this, cloner);
    }

    [StorableHook(HookType.AfterDeserialization)]
    private void AfterDeserialization() {
      if (problem == null) return;
      problem.SolutionCreatorChanged += OnUpdateRequired;
      if (problem.Encoding?.Parameters == null) return;
      foreach (var encodingParameter in problem.Encoding.Parameters.OfType<IValueParameter>())
        encodingParameter.ValueChanged += OnParameterValueChanged;
    }
    #endregion

    public override double[] ModifiedEvaluate(Individual individual, IRandom random) {
      return Problem.Evaluate(individual, random);
    }

    public override void ModifiedAnalyze(Individual[] individuals, double[][] qualities, ResultCollection results, IRandom random) {
      Problem.Analyze(individuals, qualities, results, random);
    }

    public void UpdateState() {
      InvokeEncodingChanged();
      InvokeMaximizationChanged();
      InvokeSolutionCreatorChanged();
    }

  }
}