using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Data;
using HeuristicLab.Encodings.RealVectorEncoding;
using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
using HeuristicLab.Problems.MultiObjectiveTestFunction;

namespace HeuristicLab.Problems.TestFunctions {
  [Item("ZDT4", "//http://www.tik.ee.ethz.ch/sop/download/supplementary/testproblems/ [30.11.2015]")]
  [StorableClass]
  public class ZDT4 : MultiObjectiveTestFunction {

    public override DoubleMatrix Bounds {
      get {
        return new DoubleMatrix(new double[,] { { 0, 1 } });   //definition in the source is contradicting itself the known paretofront is for [0,1] 
      }
    }

    public override bool[] Maximization {
      get {
        return new bool[] { false, false };
      }
    }

    public override int MaximumProblemSize {
      get {
        return int.MaxValue;
      }
    }

    public override int MaximumSolutionSize {
      get {
        return 2;
      }
    }

    public override int MinimumProblemSize {
      get {
        return 1;
      }
    }

    public override int MinimumSolutionSize {
      get {
        return 2;
      }
    }

    public override int ActualSolutionSize {
      get {
        return 2;
      }

      set {
      }
    }

    [StorableConstructor]
    protected ZDT4(bool deserializing) : base(deserializing) { }
    protected ZDT4(ZDT4 original, Cloner cloner) : base(original, cloner) { }
    public ZDT4() : base() { }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new ZDT4(this, cloner);
    }



    public override double[] Evaluate(RealVector r) {
      double g = 0;
      for (int i = 1; i < r.Length; i++) {
        double v = r[i];
        g += v * v - 10 * Math.Cos(4 * Math.PI * v);
      }
      g = 1.0 + 10.0 * (r.Length - 1) + g;
      double d = r[0] / g;
      return new double[] { r[0], g * (1.0 - d * d) };
    }
  }
}