#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2016 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.Threading;
using HEAL.Attic;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Optimization;
using HeuristicLab.Parameters;

namespace HeuristicLab.Analysis.FitnessLandscape {
  [Item("FLA Characterizer", "An algorithm that executes a characteristic calculator.")]
  [StorableType("9843C276-463D-4B79-A44B-7BD1F3B23FB6")]
  [Creatable(CreatableAttribute.Categories.TestingAndAnalysis + CreatableAttribute.Categories.SplitToken + "1" + CreatableAttribute.Categories.OrderToken + "FLA", Priority = 300)]
  public sealed class FLACharacterizer : BasicAlgorithm {
    public override bool SupportsPause { get { return false; } }
    
    public IValueParameter<ICharacteristicCalculator> CalculatorParameter {
      get { return (IValueParameter<ICharacteristicCalculator>)Parameters["Calculator"]; }
    }

    public ICharacteristicCalculator Calculator {
      get { return CalculatorParameter.Value; }
    }

    [StorableConstructor]
    private FLACharacterizer(StorableConstructorFlag _) : base(_) { }
    private FLACharacterizer(FLACharacterizer original, Cloner cloner)
      : base(original, cloner) {
      RegisterEventHandlers();
    }
    public FLACharacterizer() : base() {
      Parameters.Add(new ValueParameter<ICharacteristicCalculator>("Calculator", "The FLA characteristic calculator.", new RandomWalkCalculator()));
      RegisterEventHandlers();
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new FLACharacterizer(this, cloner);
    }
    
    [StorableHook(HookType.AfterDeserialization)]
    private void AfterDeserialization() {
      RegisterEventHandlers();
    }

    private void RegisterEventHandlers() {
      CalculatorParameter.ValueChanged += CalculatorParameterOnValueChanged;
    }

    private void CalculatorParameterOnValueChanged(object sender, EventArgs e) {
      Calculator.Problem = Problem;
    }

    protected override void OnProblemChanged() {
      base.OnProblemChanged();
      Calculator.Problem = Problem;
    }

    protected override void Run(CancellationToken cancellationToken) {
      var calculator = Calculator;
      if (calculator.CanCalculate()) {
        foreach (var result in calculator.Calculate()) {
          Results.Add(result);
        }
      } else throw new InvalidOperationException("Calculator cannot be applied.");
    }
  }
}