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

  using Attributes;

  using HeuristicLab.Persistence.Default.CompositeSerializers.Storable;

  using Interpreter;
  using Stack;

  /// <summary>
  /// Pushes TRUE onto the T stack if the top two items are equal, or FALSE otherwise
  /// </summary>
  /// <typeparam name="T">Stacktype</typeparam>
  [StorableClass]
  public abstract class EqualsExpression<T> : StatelessExpression {
    protected EqualsExpression() { }
    [StorableConstructor]
    protected EqualsExpression(bool deserializing) : base(deserializing) { }

    protected void Eval(IPushStack<T> stack, IPushStack<bool> booleanStack) {
      var first = stack[1];
      var second = stack.Top;
      stack.Remove(2);

      var equal = first.Equals(second);
      booleanStack.Push(equal);
    }

    protected void Eval(IPushStack<IReadOnlyList<T>> vectorStack, IPushStack<bool> booleanStack) {
      var first = vectorStack[1];
      var second = vectorStack[0];
      vectorStack.Remove(2);

      var equal = first.SequenceEqual(second);
      booleanStack.Push(equal);
    }
  }

  [StorableClass]
  [PushExpression(
    StackTypes.Integer,
    "INTEGER.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two INTEGER items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class IntegerEqualsExpression : EqualsExpression<long> {
    public IntegerEqualsExpression() { }
    [StorableConstructor]
    protected IntegerEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.IntegerStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.Float,
    "FLOAT.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two FLOAT items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class FloatEqualsExpression : EqualsExpression<double> {
    public FloatEqualsExpression() { }
    [StorableConstructor]
    protected FloatEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.FloatStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.Boolean,
    "BOOLEAN.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two BOOLEAN items are equal, or FALSE otherwise.")]
  public class BooleanEqualsExpression : EqualsExpression<bool> {
    public BooleanEqualsExpression() { }
    [StorableConstructor]
    protected BooleanEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.BooleanStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.Name,
    "NAME.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two NAME items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class NameEqualsExpression : EqualsExpression<string> {
    public NameEqualsExpression() { }
    [StorableConstructor]
    protected NameEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.NameStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.Exec,
    "EXEC.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two EXEC items are equal, or FALSE otherwise.",
    StackTypes.Boolean,
    requiredBlockCount: 0)]
  public class ExecEqualsExpression : EqualsExpression<Expression> {
    public ExecEqualsExpression() { }
    [StorableConstructor]
    protected ExecEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.ExecStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.Code,
    "CODE.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two CODE items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class CodeEqualsExpression : EqualsExpression<Expression> {
    public CodeEqualsExpression() { }
    [StorableConstructor]
    protected CodeEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.CodeStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.Char,
    "CHAR.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two CHAR items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class CharEqualsExpression : EqualsExpression<char> {
    public CharEqualsExpression() { }
    [StorableConstructor]
    protected CharEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.CharStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.String,
    "STRING.=",
    "Pushes TRUE onto the BOOLEAN stack if the top two STRING items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class StringEqualsExpression : EqualsExpression<string> {
    public StringEqualsExpression() { }
    [StorableConstructor]
    protected StringEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.StringStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.IntegerVector,
    "INTEGER[].=",
    "Pushes TRUE onto the BOOLEAN stack if the top two INTEGER[] items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class IntegerVectorEqualsExpression : EqualsExpression<long> {
    public IntegerVectorEqualsExpression() { }
    [StorableConstructor]
    protected IntegerVectorEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.IntegerVectorStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.FloatVector,
    "FLOAT[].=",
    "Pushes TRUE onto the BOOLEAN stack if the top two FLOAT[] items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class FloatVectorEqualsExpression : EqualsExpression<double> {
    public FloatVectorEqualsExpression() { }
    [StorableConstructor]
    protected FloatVectorEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.FloatVectorStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.BooleanVector,
    "BOOLEAN[].=",
    "Pushes TRUE onto the BOOLEAN stack if the top two BOOLEAN[] items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class BooleanVectorEqualsExpression : EqualsExpression<bool> {
    public BooleanVectorEqualsExpression() { }
    [StorableConstructor]
    protected BooleanVectorEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.BooleanVectorStack.Count < 2;
    }

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

  [StorableClass]
  [PushExpression(
    StackTypes.StringVector,
    "STRING[].=",
    "Pushes TRUE onto the BOOLEAN stack if the top two STRING[] items are equal, or FALSE otherwise.",
    StackTypes.Boolean)]
  public class StringVectorEqualsExpression : EqualsExpression<string> {
    public StringVectorEqualsExpression() { }
    [StorableConstructor]
    protected StringVectorEqualsExpression(bool deserializing) : base(deserializing) { }

    public override bool IsNoop(IInternalPushInterpreter interpreter) {
      return interpreter.StringVectorStack.Count < 2;
    }

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