namespace HeuristicLab.Problems.ProgramSynthesis.Push.Expressions {
  using System.Collections.Generic;

  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>
  /// Conj's an item onto the type stack.
  /// </summary>
  [StorableClass]
  public abstract class VectorConjExpression<T> : StatelessExpression {
    protected VectorConjExpression() { }
    [StorableConstructor]
    protected VectorConjExpression(bool deserializing) : base(deserializing) { }

    protected bool IsNoop(IInternalPushInterpreter interpreter, IPushStack<IReadOnlyList<T>> vectorStack, IPushStack<T> literalStack) {
      return vectorStack.IsEmpty ||
             literalStack.IsEmpty ||
             vectorStack.Top.Count + 1 > interpreter.Configuration.MaxVectorLength;
    }

    protected void Eval(IInternalPushInterpreter interpreter, IPushStack<IReadOnlyList<T>> vectorStack, IPushStack<T> literalStack) {
      var literal = literalStack.Pop();
      vectorStack.Top = new List<T>(vectorStack.Top) { literal };
    }
  }

  [StorableClass]
  [PushExpression(
    StackTypes.IntegerVector,
    "INTEGER[].CONJ",
    "Conj's the top INTEGER onto the top item of the INTEGER[] stack.",
    StackTypes.Integer)]
  public class IntegerVectorConjExpression : VectorConjExpression<long> {
    public IntegerVectorConjExpression() { }
    [StorableConstructor]
    protected IntegerVectorConjExpression(bool deserializing) : base(deserializing) { }

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

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

  [StorableClass]
  [PushExpression(
    StackTypes.FloatVector,
    "FLOAT[].CONJ",
    "Conj's the top FLOAT onto the top item of the FLOAT[] stack.",
    StackTypes.Float)]
  public class FloatVectorConjExpression : VectorConjExpression<double> {
    public FloatVectorConjExpression() { }
    [StorableConstructor]
    protected FloatVectorConjExpression(bool deserializing) : base(deserializing) { }

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

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

  [StorableClass]
  [PushExpression(
    StackTypes.StringVector,
    "STRING[].CONJ",
    "Conj's the top STRING onto the top item of the STRING[] stack.",
    StackTypes.String)]
  public class StringVectorConjExpression : VectorConjExpression<string> {
    public StringVectorConjExpression() { }
    [StorableConstructor]
    protected StringVectorConjExpression(bool deserializing) : base(deserializing) { }

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

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

  [StorableClass]
  [PushExpression(
    StackTypes.BooleanVector,
    "BOOLEAN[].CONJ",
    "Conj's the top BOOLEAN onto the top item of the BOOLEAN[] stack.",
    StackTypes.Boolean)]
  public class BooleanVectorConjExpression : VectorConjExpression<bool> {
    public BooleanVectorConjExpression() { }
    [StorableConstructor]
    protected BooleanVectorConjExpression(bool deserializing) : base(deserializing) { }

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

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