using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using HEAL.Attic;
using HeuristicLab.Common;
using HeuristicLab.Core;
using HeuristicLab.Optimization;

namespace HeuristicLab.Problems.Modifiers {
  [StorableType("3985D750-03D4-4842-A34D-A352BED95190")]
  public sealed class MultiObjectiveBasicProblemEvaluation : BasicAlgorithm {
    public override bool SupportsPause => false;

    public new MultiObjectiveBasicProblem<IEncoding> Problem {
      get => (MultiObjectiveBasicProblem<IEncoding>)base.Problem;
      private set => base.Problem = value;
    }

    [Storable]
    public IScope IndividualScope { get; private set; }
    [Storable]
    public IRandom Random { get; private set; }
    [Storable]
    public double[] Qualities { get; private set; }

    #region Constructors & Cloning
    [StorableConstructor]
    private MultiObjectiveBasicProblemEvaluation(StorableConstructorFlag _) : base(_) { }
    private MultiObjectiveBasicProblemEvaluation(MultiObjectiveBasicProblemEvaluation original, Cloner cloner) : base(original, cloner) {
      IndividualScope = cloner.Clone(original.IndividualScope);
      Random = cloner.Clone(original.Random);
      Qualities = (double[])original.Qualities.Clone();
    }
    public MultiObjectiveBasicProblemEvaluation(MultiObjectiveBasicProblem<IEncoding> problem, IScope individualScope, IRandom random) {
      Problem = problem;
      IndividualScope = individualScope;
      Random = random;
      Qualities = Enumerable.Repeat(double.NaN, problem.Maximization.Length).ToArray();
    }

    public override IDeepCloneable Clone(Cloner cloner) {
      return new MultiObjectiveBasicProblemEvaluation(this, cloner);
    }
    #endregion

    protected override void Run(CancellationToken cancellationToken) {
      var singleEncoding = Problem.Encoding;
      var individual = Problem.Encoding is MultiEncoding multiEncoding
        ? (Individual)new MultiEncodingIndividual(multiEncoding, IndividualScope)
        : (Individual)new SingleEncodingIndividual(singleEncoding, IndividualScope);
      var evaluationTask = Task.Run(() => Problem.Evaluate(individual, Random), cancellationToken);
      evaluationTask.Wait(cancellationToken);
      Qualities = evaluationTask.Result;
    }
  }
}