using System;

namespace HeuristicLab.Problems.ProgramSynthesis.Base.Erc.Boolean {
  using HeuristicLab.Common;
  using HeuristicLab.Core;
  using HeuristicLab.Data;
  using HeuristicLab.Parameters;
  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

  [StorableClass]
  public class BooleanRandomErcValue : WeightedErcValueItem<bool> {

    private const string AllowTrueParameterName = "Allow true";
    private const string AllowFalseParameterName = "Allow false";

    public BooleanRandomErcValue() : this(false, true, true) { }

    public BooleanRandomErcValue(bool isEnabled, bool allowTrue, bool allowFalse) {
      if (!allowTrue && allowFalse) {
        throw new InvalidOperationException("true and false values are disabled");
      }

      Name = "Boolean random";
      IsEnabled = isEnabled;
      Parameters.Add(new FixedValueParameter<BoolValue>(AllowTrueParameterName, new BoolValue(allowTrue)));
      Parameters.Add(new FixedValueParameter<BoolValue>(AllowFalseParameterName, new BoolValue(allowFalse)));
    }

    [StorableConstructor]
    public BooleanRandomErcValue(bool deserializing) : base(deserializing) { }

    public BooleanRandomErcValue(BooleanRandomErcValue origin, Cloner cloner) : base(origin, cloner) {
      this.AllowFalse = origin.AllowFalse;
      this.AllowTrue = origin.AllowTrue;
    }

    public IValueParameter<BoolValue> AllowFalseParameter
    {
      get { return (IValueParameter<BoolValue>)Parameters[AllowFalseParameterName]; }
    }

    public bool AllowFalse
    {
      get { return AllowFalseParameter.Value.Value; }
      set { AllowFalseParameter.Value.Value = value; }
    }

    public IValueParameter<BoolValue> AllowTrueParameter
    {
      get { return (IValueParameter<BoolValue>)Parameters[AllowTrueParameterName]; }
    }

    public bool AllowTrue
    {
      get { return AllowTrueParameter.Value.Value; }
      set { AllowTrueParameter.Value.Value = value; }
    }

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

    public override bool GetErcValue(IRandom random) {
      if (!this.AllowTrue && !this.AllowFalse) throw new InvalidOperationException();
      if (!this.AllowFalse) return true;
      if (!this.AllowTrue) return false;

      return random.NextDouble() >= 0.5;
    }
  }
}