using System.Collections.Generic;

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

  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;
  using HeuristicLab.Problems.ProgramSynthesis.Push.Attributes;
  using HeuristicLab.Problems.ProgramSynthesis.Push.Interpreter;
  using HeuristicLab.Problems.ProgramSynthesis.Push.Stack;

  /// <summary>
  /// Removes all occurrences of the first lit-type item in the top type vector.
  /// </summary>
  /// <typeparam name="T"></typeparam>
  [StorableClass]
  public abstract class VectorRemoveExpression<T> : StatelessExpression {
    protected VectorRemoveExpression() { }
    [StorableConstructor]
    protected VectorRemoveExpression(bool deserializing) : base(deserializing) { }

    protected bool IsNoop(IPushStack<IReadOnlyList<T>> vectorStack, IPushStack<T> literalStack) {
      return vectorStack.IsEmpty || literalStack.IsEmpty;
    }

    protected void Eval(IPushStack<IReadOnlyList<T>> vectorStack, IPushStack<T> literalStack) {
      var literal = literalStack.Pop();
      vectorStack.Top = vectorStack.Top.Where(x => !x.Equals(literal)).ToList();
    }
  }

  [StorableClass]
  [PushExpression(
    StackTypes.IntegerVector,
    "INTEGER[].REMOVE",
    "Removes all occurrences of the top INTEGER in the top INTEGER[].",
    StackTypes.Integer)]
  public class IntegerVectorRemoveExpression : VectorRemoveExpression<long> {
    public IntegerVectorRemoveExpression() { }
    [StorableConstructor]
    protected IntegerVectorRemoveExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return IsNoop(interpreter.IntegerVectorStack, interpreter.IntegerStack);
    }

    public override void Eval(IInternalPushInterpreter interpreter) {
      Eval(interpreter.IntegerVectorStack, interpreter.IntegerStack);
    }
  }

  [StorableClass]
  [PushExpression(
    StackTypes.FloatVector,
    "FLOAT[].REMOVE",
    "Removes all occurrences of the top FLOAT in the top FLOAT[].",
    StackTypes.Float)]
  public class FloatVectorRemoveExpression : VectorRemoveExpression<double> {
    public FloatVectorRemoveExpression() { }
    [StorableConstructor]
    protected FloatVectorRemoveExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return IsNoop(interpreter.FloatVectorStack, interpreter.FloatStack);
    }

    public override void Eval(IInternalPushInterpreter interpreter) {
      Eval(interpreter.FloatVectorStack, interpreter.FloatStack);
    }
  }

  [StorableClass]
  [PushExpression(
    StackTypes.BooleanVector,
    "BOOLEAN[].REMOVE",
    "Removes all occurrences of the top BOOLEAN in the top BOOLEAN[].",
    StackTypes.Boolean)]
  public class BooleanVectorRemoveExpression : VectorRemoveExpression<bool> {
    public BooleanVectorRemoveExpression() { }
    [StorableConstructor]
    protected BooleanVectorRemoveExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return IsNoop(interpreter.BooleanVectorStack, interpreter.BooleanStack);
    }

    public override void Eval(IInternalPushInterpreter interpreter) {
      Eval(interpreter.BooleanVectorStack, interpreter.BooleanStack);
    }
  }

  [StorableClass]
  [PushExpression(
    StackTypes.StringVector,
    "STRING[].REMOVE",
    "Removes all occurrences of the top STRING in the top STRING[].",
    StackTypes.String)]
  public class StringVectorRemoveExpression : VectorRemoveExpression<string> {
    public StringVectorRemoveExpression() { }
    [StorableConstructor]
    protected StringVectorRemoveExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return IsNoop(interpreter.StringVectorStack, interpreter.StringStack);
    }

    public override void Eval(IInternalPushInterpreter interpreter) {
      Eval(interpreter.StringVectorStack, interpreter.StringStack);
    }
  }
}