#region License Information
/* HeuristicLab
 * Copyright (C) 2002-2019 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.Analysis;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Encodings.RealVectorEncoding;
using HeuristicLab.Optimization;
using HeuristicLab.Optimization.Operators;
using HeuristicLab.Parameters;
using HEAL.Attic;
using HeuristicLab.Problems.Instances;

namespace HeuristicLab.Problems.TestFunctions {
  [Item("Test Function (single-objective)", "Test function with real valued inputs and a single objective.")]
  [StorableType("F0AB7236-2C9B-49DC-9D4F-A3558FD9E992")]
  [Creatable(CreatableAttribute.Categories.Problems, Priority = 90)]
  public sealed class SingleObjectiveTestFunctionProblem :
    SingleObjectiveProblem<RealVectorEncoding, RealVector>,
    IProblemInstanceConsumer<SOTFData> {

    public override bool Maximization {
      get { return Parameters.ContainsKey("TestFunction") && TestFunction.Maximization; }
    }

    #region Parameter Properties
    private IFixedValueParameter<IntValue> ProblemSizeParameter {
      get { return (IFixedValueParameter<IntValue>)Parameters["ProblemSize"]; }
    }
    private IValueParameter<DoubleMatrix> BoundsParameter {
      get { return (IValueParameter<DoubleMatrix>)Parameters["Bounds"]; }
    }
    public OptionalValueParameter<RealVector> BestKnownSolutionParameter {
      get { return (OptionalValueParameter<RealVector>)Parameters["BestKnownSolution"]; }
    }
    public IValueParameter<ISingleObjectiveTestFunction> TestFunctionParameter {
      get { return (IValueParameter<ISingleObjectiveTestFunction>)Parameters["TestFunction"]; }
    }
    #endregion

    #region Properties
    public int ProblemSize {
      get { return ProblemSizeParameter.Value.Value; }
      set { ProblemSizeParameter.Value.Value = value; }
    }
    public DoubleMatrix Bounds {
      get { return BoundsParameter.Value; }
      set { BoundsParameter.Value = value; }
    }
    public ISingleObjectiveTestFunction TestFunction {
      get { return TestFunctionParameter.Value; }
      set { TestFunctionParameter.Value = value; }
    }

    private BestSingleObjectiveTestFunctionSolutionAnalyzer BestSingleObjectiveTestFunctionSolutionAnalyzer {
      get { return Operators.OfType<BestSingleObjectiveTestFunctionSolutionAnalyzer>().FirstOrDefault(); }
    }
    #endregion

    [StorableConstructor]
    private SingleObjectiveTestFunctionProblem(StorableConstructorFlag _) : base(_) { }
    private SingleObjectiveTestFunctionProblem(SingleObjectiveTestFunctionProblem original, Cloner cloner)
      : base(original, cloner) {
      RegisterEventHandlers();
    }
    public SingleObjectiveTestFunctionProblem()
      : base(new RealVectorEncoding("Point")) {
      Parameters.Add(new FixedValueParameter<IntValue>("ProblemSize", "The dimensionality of the problem instance (number of variables in the function).", new IntValue(2)));
      Parameters.Add(new ValueParameter<DoubleMatrix>("Bounds", "The bounds of the solution given as either one line for all variables or a line for each variable. The first column specifies lower bound, the second upper bound.", new DoubleMatrix(new double[,] { { -100, 100 } })));
      Parameters.Add(new OptionalValueParameter<RealVector>("BestKnownSolution", "The best known solution for this test function instance."));
      Parameters.Add(new ValueParameter<ISingleObjectiveTestFunction>("TestFunction", "The function that is to be optimized.", new Ackley()));

      Encoding.LengthParameter = ProblemSizeParameter;
      Encoding.BoundsParameter = BoundsParameter;
      BestKnownQuality = TestFunction.BestKnownQuality;

      InitializeOperators();
      RegisterEventHandlers();
    }

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

    [StorableHook(HookType.AfterDeserialization)]
    private void AfterDeserialization() {
      RegisterEventHandlers();
    }

    private void RegisterEventHandlers() {
      Evaluator.QualityParameter.ActualNameChanged += Evaluator_QualityParameter_ActualNameChanged;
      TestFunctionParameter.ValueChanged += TestFunctionParameterOnValueChanged;
      ProblemSizeParameter.Value.ValueChanged += ProblemSizeOnValueChanged;
      BoundsParameter.ValueChanged += BoundsParameterOnValueChanged;
    }

    public override double Evaluate(RealVector individual, IRandom random) {
      return TestFunction.Evaluate(individual);
    }

    #region Events
    protected override void OnEncodingChanged() {
      base.OnEncodingChanged();
      Parameterize();
    }
    protected override void OnEvaluatorChanged() {
      base.OnEvaluatorChanged();
      Evaluator.QualityParameter.ActualNameChanged += Evaluator_QualityParameter_ActualNameChanged;
      Parameterize();
    }
    private void Evaluator_QualityParameter_ActualNameChanged(object sender, EventArgs e) {
      Parameterize();
    }
    private void TestFunctionParameterOnValueChanged(object sender, EventArgs eventArgs) {
      var problemSizeChange = ProblemSize < TestFunction.MinimumProblemSize
                              || ProblemSize > TestFunction.MaximumProblemSize;
      if (problemSizeChange) {
        ProblemSize = Math.Max(TestFunction.MinimumProblemSize, Math.Min(ProblemSize, TestFunction.MaximumProblemSize));
      }
      BestKnownQuality = TestFunction.BestKnownQuality;
      Bounds = (DoubleMatrix)TestFunction.Bounds.Clone();
      var bestSolution = TestFunction.GetBestKnownSolution(ProblemSize);
      BestKnownSolutionParameter.Value = bestSolution;

      OnReset();
    }
    private void ProblemSizeOnValueChanged(object sender, EventArgs eventArgs) {
      if (ProblemSize < TestFunction.MinimumProblemSize
        || ProblemSize > TestFunction.MaximumProblemSize)
        ProblemSize = Math.Min(TestFunction.MaximumProblemSize, Math.Max(TestFunction.MinimumProblemSize, ProblemSize));
    }
    private void BoundsParameterOnValueChanged(object sender, EventArgs eventArgs) {
      Parameterize();
    }
    #endregion

    #region Helpers
    private void InitializeOperators() {
      Operators.Add(new SingleObjectiveTestFunctionImprovementOperator());
      Operators.Add(new SingleObjectiveTestFunctionPathRelinker());
      Operators.Add(new SingleObjectiveTestFunctionSimilarityCalculator());
      Operators.Add(new HammingSimilarityCalculator());
      Operators.Add(new EuclideanSimilarityCalculator());
      Operators.Add(new QualitySimilarityCalculator());
      Operators.Add(new AdditiveMoveEvaluator());

      Operators.Add(new BestSingleObjectiveTestFunctionSolutionAnalyzer());
      Operators.Add(new PopulationSimilarityAnalyzer(Operators.OfType<ISolutionSimilarityCalculator>()));
      Parameterize();
    }

    private void Parameterize() {
      var operators = new List<IItem>();
      if (BestSingleObjectiveTestFunctionSolutionAnalyzer != null) {
        operators.Add(BestSingleObjectiveTestFunctionSolutionAnalyzer);
        BestSingleObjectiveTestFunctionSolutionAnalyzer.QualityParameter.ActualName = Evaluator.QualityParameter.ActualName;
        BestSingleObjectiveTestFunctionSolutionAnalyzer.BestKnownQualityParameter.ActualName = BestKnownQualityParameter.Name;
        BestSingleObjectiveTestFunctionSolutionAnalyzer.BestKnownSolutionParameter.ActualName = BestKnownSolutionParameter.Name;
        BestSingleObjectiveTestFunctionSolutionAnalyzer.MaximizationParameter.ActualName = MaximizationParameter.Name;
        BestSingleObjectiveTestFunctionSolutionAnalyzer.TestFunctionParameter.ActualName = TestFunctionParameter.Name;
      }
      foreach (var op in Operators.OfType<ISingleObjectiveTestFunctionAdditiveMoveEvaluator>()) {
        operators.Add(op);
        op.QualityParameter.ActualName = Evaluator.QualityParameter.ActualName;
        op.QualityParameter.Hidden = true;
        foreach (var movOp in Encoding.Operators.OfType<IRealVectorAdditiveMoveQualityOperator>())
          movOp.MoveQualityParameter.ActualName = op.MoveQualityParameter.ActualName;
      }
      foreach (var op in Operators.OfType<IRealVectorParticleCreator>()) {
        // TODO: unified encoding parameters
        op.RealVectorParameter.ActualName = ((IRealVectorSolutionOperator)Encoding.SolutionCreator).RealVectorParameter.ActualName;
        op.RealVectorParameter.Hidden = true;
        op.BoundsParameter.ActualName = BoundsParameter.Name;
        op.BoundsParameter.Hidden = true;
      }
      foreach (var op in Operators.OfType<IRealVectorParticleUpdater>()) {
        // TODO: unified encoding parameters
        op.RealVectorParameter.ActualName = ((IRealVectorSolutionOperator)Encoding.SolutionCreator).RealVectorParameter.ActualName;
        op.RealVectorParameter.Hidden = true;
        op.BoundsParameter.ActualName = BoundsParameter.Name;
        op.BoundsParameter.Hidden = true;
      }
      foreach (var op in Operators.OfType<IRealVectorSwarmUpdater>()) {
        op.MaximizationParameter.ActualName = MaximizationParameter.Name;
        op.MaximizationParameter.Hidden = true;
      }
      foreach (var op in Operators.OfType<ISingleObjectiveImprovementOperator>()) {
        operators.Add(op);
        op.SolutionParameter.ActualName = Encoding.Name;
        op.SolutionParameter.Hidden = true;
      }
      foreach (var op in Operators.OfType<ITestFunctionSolutionSimilarityCalculator>()) {
        operators.Add(op);
        op.SolutionVariableName = Encoding.Name;
        op.QualityVariableName = Evaluator.QualityParameter.ActualName;
        op.Bounds = Bounds;
      }

      if (operators.Count > 0) Encoding.ConfigureOperators(operators);
    }
    #endregion

    public void Load(SOTFData data) {
      Name = data.Name;
      Description = data.Description;
      TestFunction = data.TestFunction;
    }
  }
}