namespace HeuristicLab.Problems.ProgramSynthesis.Base.Erc {
  using System;

  using HeuristicLab.Common;
  using HeuristicLab.Core;
  using HeuristicLab.Data;
  using HeuristicLab.Parameters;
  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

  [StorableClass]
  public abstract class WeightedErcItem<T> : ParameterizedNamedItem, IWeightedErcItem<T> {
    private const string WeightParameterName = "Weight";

    [Storable]
    protected bool isEnabled;

    public event EventHandler<bool> EnabledChanged;

    protected WeightedErcItem() : this(false, 1d) { }

    protected WeightedErcItem(bool isEnabled, double weigth) {
      this.isEnabled = isEnabled;
      Parameters.Add(new FixedValueParameter<DoubleValue>(WeightParameterName, new DoubleValue(weigth)));
    }

    [StorableConstructor]
    protected WeightedErcItem(bool deserializing) : base(deserializing) { }

    protected WeightedErcItem(WeightedErcItem<T> origin, Cloner cloner)
      : base(origin, cloner) {
      isEnabled = origin.IsEnabled;
    }

    public IValueParameter<DoubleValue> WeightParameter
    {
      get { return (IValueParameter<DoubleValue>)Parameters[WeightParameterName]; }
    }

    public double Weight
    {
      get { return WeightParameter.Value.Value; }
      set { WeightParameter.Value.Value = value; }
    }

    public bool IsEnabled
    {
      get { return isEnabled; }
      set
      {
        if (value == isEnabled)
          return;

        isEnabled = value;

        if (EnabledChanged != null)
          EnabledChanged(this, value);
      }
    }

    public abstract T GetErcValue(IRandom random);
  }
}