using System.Collections.Generic;

namespace HeuristicLab.Problems.ProgramSynthesis {
  using System;
  using System.Linq;

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

  [Item("PlushEncoding", "Describes an linear push (Plush) encoding.")]
  [StorableClass]
  public class PlushEncoding : Encoding<IPlushCreator> {

    public PlushEncoding() : this("Plush") { }

    public PlushEncoding(string name) : base(name) {
      InitParameters();

      SolutionCreator = new PlushCreator();
      RegisterParameterEvents();
      DiscoverOperators();
    }

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

    public PlushEncoding(PlushEncoding original, Cloner cloner)
      : base(original, cloner) {
      minLengthParameter = cloner.Clone(original.minLengthParameter);
      maxLengthParameter = cloner.Clone(original.maxLengthParameter);
      maxCloseParameter = cloner.Clone(original.maxCloseParameter);
      closeBiasLevelParameter = cloner.Clone(original.closeBiasLevelParameter);
      instructionsParameter = cloner.Clone(original.instructionsParameter);
      ercOptionsParameter = cloner.Clone(original.ercOptionsParameter);
      inInstructionProbabilityParameter = cloner.Clone(original.inInstructionProbabilityParameter);

      RegisterParameterEvents();
    }

    [StorableHook(HookType.AfterDeserialization)]
    private void AfterDeserialization() {
      InitParameters();
      RegisterParameterEvents();
      DiscoverOperators();
    }

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

    private void InitParameters() {
      if (!Parameters.ContainsKey(Name + ".MinLength")) {
        minLengthParameter = new FixedValueParameter<IntValue>(Name + ".MinLength", new IntValue(0));
        Parameters.Add(minLengthParameter);
      }

      if (!Parameters.ContainsKey(Name + ".MaxLength")) {
        maxLengthParameter = new FixedValueParameter<IntValue>(Name + ".MaxLength", new IntValue(100));
        Parameters.Add(maxLengthParameter);
      }

      if (!Parameters.ContainsKey(Name + ".MaxClose")) {
        maxCloseParameter = new FixedValueParameter<IntValue>(Name + ".MaxClose", new IntValue(3));
        Parameters.Add(maxCloseParameter);
      }

      if (!Parameters.ContainsKey(Name + ".CloseBiasLevel")) {
        closeBiasLevelParameter = new FixedValueParameter<DoubleValue>(Name + ".CloseBiasLevel", new DoubleValue(3d));
        Parameters.Add(closeBiasLevelParameter);
      }

      if (!Parameters.ContainsKey(Name + ".Instructions")) {
        instructionsParameter = new ValueParameter<IExpressionsConfiguration>(Name + ".Instructions");
        Parameters.Add(instructionsParameter);
      }

      if (!Parameters.ContainsKey(Name + ".ErcOptions")) {
        ercOptionsParameter = new ValueParameter<ErcOptions>(Name + ".ErcOptions");
        Parameters.Add(ercOptionsParameter);
      }

      if (!Parameters.ContainsKey(Name + ".InInstructionProbability")) {
        inInstructionProbabilityParameter = new FixedValueParameter<PercentValue>(Name + ".InInstructionProbability", new PercentValue(0.1));
        Parameters.Add(inInstructionProbabilityParameter);
      }
    }

    #region events

    private void OnMinLengthParameterChanged() {
      RegisterMinLengthParameterEvents();
      ConfigureOperators(Operators);
    }
    private void OnMaxLengthParameterChanged() {
      RegisterMaxLengthParameterEvents();
      ConfigureOperators(Operators);
    }
    private void OnMaxCloseParameterChanged() {
      RegisterMaxCloseParameterEvents();
      ConfigureOperators(Operators);
    }
    private void OnCloseBiasLevelParameterChanged() {
      RegisterCloseBiasLevelParameterEvents();
      ConfigureOperators(Operators);
    }
    private void OnErcOptionsParameterChanged() {
      RegisterErcOptionsParameterEvents();
      ConfigureOperators(Operators);
    }
    private void OnInstructionsParameterChanged() {
      RegisterInstructionsParameterEvents();
      ConfigureOperators(Operators);
    }
    private void OnInInstructionProbabilityParameterChanged() {
      RegisterInInstructionProbabilityParameterEvents();
      ConfigureOperators(Operators);
    }

    private void RegisterParameterEvents() {
      RegisterMinLengthParameterEvents();
      RegisterMaxLengthParameterEvents();
      RegisterMaxCloseParameterEvents();
      RegisterCloseBiasLevelParameterEvents();
      RegisterErcOptionsParameterEvents();
      RegisterInstructionsParameterEvents();
      RegisterInInstructionProbabilityParameterEvents();
    }

    private void RegisterMinLengthParameterEvents() {
      MinLengthParameter.ValueChanged += (o, s) => ConfigureOperators(Operators);
      MinLengthParameter.Value.ValueChanged += (o, s) => ConfigureOperators(Operators);
    }

    private void RegisterMaxLengthParameterEvents() {
      MaxLengthParameter.ValueChanged += (o, s) => ConfigureOperators(Operators);
      MaxLengthParameter.Value.ValueChanged += (o, s) => ConfigureOperators(Operators);
    }

    private void RegisterMaxCloseParameterEvents() {
      MaxCloseParameter.ValueChanged += (o, s) => ConfigureOperators(Operators);
      MaxCloseParameter.Value.ValueChanged += (o, s) => ConfigureOperators(Operators);
    }

    private void RegisterCloseBiasLevelParameterEvents() {
      CloseBiasLevelParameter.ValueChanged += (o, s) => ConfigureOperators(Operators);
      CloseBiasLevelParameter.Value.ValueChanged += (o, s) => ConfigureOperators(Operators);
    }

    private void RegisterInInstructionProbabilityParameterEvents() {
      InInstructionProbabilityParameter.ValueChanged += (o, s) => ConfigureOperators(Operators);
      InInstructionProbabilityParameter.Value.ValueChanged += (o, s) => ConfigureOperators(Operators);
    }

    private void RegisterErcOptionsParameterEvents() {
      ErcOptionsParameter.ValueChanged += (o, s) => ConfigureOperators(Operators);
    }

    private void RegisterInstructionsParameterEvents() {
      InstructionsParameter.ValueChanged += (o, s) => ConfigureOperators(Operators);
    }

    #endregion

    #region Encoding Parameters
    [Storable]
    private IValueParameter<IntValue> minLengthParameter;
    public IValueParameter<IntValue> MinLengthParameter {
      get { return minLengthParameter; }
      set {
        if (value == null) throw new ArgumentNullException("Min length parameter must not be null.");
        if (value.Value == null) throw new ArgumentNullException("Min length parameter value must not be null.");
        if (minLengthParameter == value) return;

        if (minLengthParameter != null) Parameters.Remove(minLengthParameter);
        minLengthParameter = value;
        Parameters.Add(minLengthParameter);
        OnMinLengthParameterChanged();
      }
    }

    [Storable]
    private IValueParameter<IntValue> maxLengthParameter;
    public IValueParameter<IntValue> MaxLengthParameter {
      get { return maxLengthParameter; }
      set {
        if (value == null) throw new ArgumentNullException("Max length parameter must not be null.");
        if (value.Value == null) throw new ArgumentNullException("Max length parameter value must not be null.");
        if (maxLengthParameter == value) return;

        if (maxLengthParameter != null) Parameters.Remove(maxLengthParameter);
        maxLengthParameter = value;
        Parameters.Add(maxLengthParameter);
        OnMaxLengthParameterChanged();
      }
    }

    [Storable]
    private IValueParameter<IntValue> maxCloseParameter;
    public IValueParameter<IntValue> MaxCloseParameter {
      get { return maxCloseParameter; }
      set {
        if (value == null) throw new ArgumentNullException("Max close parameter must not be null.");
        if (value.Value == null) throw new ArgumentNullException("Max close parameter value must not be null.");
        if (maxCloseParameter == value) return;

        if (maxCloseParameter != null) Parameters.Remove(maxCloseParameter);
        maxCloseParameter = value;
        Parameters.Add(maxCloseParameter);
        OnMaxCloseParameterChanged();
      }
    }

    [Storable]
    private IValueParameter<DoubleValue> closeBiasLevelParameter;
    public IValueParameter<DoubleValue> CloseBiasLevelParameter {
      get { return closeBiasLevelParameter; }
      set {
        if (value == null) throw new ArgumentNullException("Close bias level parameter must not be null.");
        if (value.Value == null) throw new ArgumentNullException("Close bias level parameter value must not be null.");
        if (closeBiasLevelParameter == value) return;

        if (closeBiasLevelParameter != null) Parameters.Remove(closeBiasLevelParameter);
        closeBiasLevelParameter = value;
        Parameters.Add(closeBiasLevelParameter);
        OnCloseBiasLevelParameterChanged();
      }
    }

    [Storable]
    private IValueParameter<PercentValue> inInstructionProbabilityParameter;
    public IValueParameter<PercentValue> InInstructionProbabilityParameter {
      get { return inInstructionProbabilityParameter; }
      set {
        if (value == null) throw new ArgumentNullException("In instruciton probability parameter must not be null.");
        if (value.Value == null) throw new ArgumentNullException("In instruciton probability parameter value must not be null.");
        if (inInstructionProbabilityParameter == value) return;

        if (inInstructionProbabilityParameter != null) Parameters.Remove(inInstructionProbabilityParameter);
        inInstructionProbabilityParameter = value;
        Parameters.Add(inInstructionProbabilityParameter);
        OnInInstructionProbabilityParameterChanged();
      }
    }

    [Storable]
    private IValueParameter<IExpressionsConfiguration> instructionsParameter;
    public IValueParameter<IExpressionsConfiguration> InstructionsParameter {
      get { return instructionsParameter; }
      set {
        if (value == null) throw new ArgumentNullException("Instructions paramter must not be null");
        if (instructionsParameter == value) return;

        if (instructionsParameter != null) Parameters.Remove(instructionsParameter);
        instructionsParameter = value;
        Parameters.Add(instructionsParameter);
        OnInstructionsParameterChanged();
      }
    }

    [Storable]
    private IValueParameter<ErcOptions> ercOptionsParameter;
    public IValueParameter<ErcOptions> ErcOptionsParameter {
      get { return ercOptionsParameter; }
      set {
        if (value == null) throw new ArgumentNullException("ErcOptions paramter must not be null");
        if (ercOptionsParameter == value) return;

        if (ercOptionsParameter != null) Parameters.Remove(ercOptionsParameter);
        ercOptionsParameter = value;
        Parameters.Add(ercOptionsParameter);
        OnErcOptionsParameterChanged();
      }
    }

    public IExpressionsConfiguration Instructions {
      get { return InstructionsParameter.Value; }
      set { InstructionsParameter.Value = value; }
    }

    public ErcOptions ErcOptions {
      get { return ErcOptionsParameter.Value; }
      set { ErcOptionsParameter.Value = value; }
    }

    public int MinLength {
      get { return MinLengthParameter.Value.Value; }
      set { MinLengthParameter.Value.Value = value; }
    }

    public int MaxLength {
      get { return MaxLengthParameter.Value.Value; }
      set { MaxLengthParameter.Value.Value = value; }
    }

    public int MaxClose {
      get { return MaxCloseParameter.Value.Value; }
      set { MaxCloseParameter.Value.Value = value; }
    }

    public double InInstructionProbability {
      get { return InInstructionProbabilityParameter.Value.Value; }
      set { InInstructionProbabilityParameter.Value.Value = value; }
    }
    #endregion

    #region Operator Discovery
    private static readonly IEnumerable<Type> EncodingSpecificOperatorTypes;
    static PlushEncoding() {
      EncodingSpecificOperatorTypes = new List<Type>() {
        typeof (IPlushOperator),
        typeof (IPlushCreator),
        typeof (IPlushCrossover),
        typeof (IPlushManipulator),
      };
    }

    private void DiscoverOperators() {
      var assembly = typeof(IPlushOperator).Assembly;
      var discoveredTypes = ApplicationManager.Manager.GetTypes(EncodingSpecificOperatorTypes, assembly, true, false, false);
      var operators = discoveredTypes.Select(t => (IOperator)Activator.CreateInstance(t));
      var newOperators = operators.Except(Operators, new TypeEqualityComparer<IOperator>()).ToList();

      ConfigureOperators(newOperators);
      foreach (var @operator in newOperators)
        AddOperator(@operator);
    }
    #endregion

    public override void ConfigureOperators(IEnumerable<IOperator> operators) {
      ConfigureCreators(operators.OfType<IPlushCreator>());
      ConfigureCrossovers(operators.OfType<IPlushCrossover>());
      ConfigureManipulators(operators.OfType<IPlushManipulator>());
    }

    private void ConfigureCreators(IEnumerable<IPlushCreator> creators) {
      foreach (var creator in creators) {
        creator.PlushVectorParameter.ActualName = Name;
        creator.MinLengthParameter.ActualName = MinLengthParameter.Name;
        creator.MaxLengthParameter.ActualName = MaxLengthParameter.Name;
        creator.MaxCloseParameter.ActualName = MaxCloseParameter.Name;
        creator.CloseBiasLevelParameter.ActualName = CloseBiasLevelParameter.Name;
        creator.ErcOptionsParameter.ActualName = ErcOptionsParameter.Name;
        creator.InstructionsParameter.ActualName = InstructionsParameter.Name;
        creator.InInstructionProbabilityParameter.ActualName = InInstructionProbabilityParameter.Name;
      }
    }

    private void ConfigureCrossovers(IEnumerable<IPlushCrossover> crossovers) {
      foreach (var crossover in crossovers) {
        crossover.ChildParameter.ActualName = Name;
        crossover.ParentsParameter.ActualName = Name;
      }
    }

    private void ConfigureManipulators(IEnumerable<IPlushManipulator> manipulators) {
      foreach (var manipulator in manipulators) {
        manipulator.PlushVectorParameter.ActualName = Name;
        manipulator.PlushVectorParameter.Hidden = true;

        manipulator.ErcOptionsParameter.ActualName = ErcOptionsParameter.Name;
        manipulator.InstructionsParameter.ActualName = InstructionsParameter.Name;
        manipulator.InInstructionProbabilityParameter.ActualName = InInstructionProbabilityParameter.Name;
      }
    }
  }

  public static class IndividualExtensionMethods {
    public static PlushVector PlushVector(this Individual individual) {
      var encoding = individual.GetEncoding<PlushEncoding>();
      return individual.PlushVector(encoding.Name);
    }

    public static PlushVector PlushVector(this Individual individual, string name) {
      return (PlushVector)individual[name];
    }
  }
}