using System;

using XSharp.Compiler;
using static XSharp.Compiler.XSRegisters;

namespace Cosmos.IL2CPU.X86.IL
{
  [Cosmos.IL2CPU.OpCode(ILOpCode.Code.Or)]
  public class Or : ILOp
  {
    public Or(Cosmos.Assembler.Assembler aAsmblr)
        : base(aAsmblr)
    {
    }

    public override void Execute(MethodInfo aMethod, ILOpCode aOpCode)
    {
      var xStackContent = aOpCode.StackPopTypes[0];
      var xStackContentSecond = aOpCode.StackPopTypes[1];
      var xStackContentSize = SizeOfType(xStackContent);
      var xStackContentSecondSize = SizeOfType(xStackContentSecond);

      var xSize = Math.Max(xStackContentSize, xStackContentSecondSize);

      if (Align(xStackContentSize, 4u) != Align(xStackContentSecondSize, 4u))
      {
        throw new NotSupportedException("Operands have different size!");
      }
      if (xSize > 8)
      {
        throw new NotImplementedException("StackSize>8 not supported");
      }

      if (xSize > 4)
      {
        // [ESP] is low part
        // [ESP + 4] is high part
        // [ESP + 8] is low part
        // [ESP + 12] is high part
        XS.Pop(EAX);
        XS.Pop(EDX);
        // [ESP] is low part
        // [ESP + 4] is high part
        XS.Or(ESP, EAX, destinationIsIndirect: true);
        XS.Or(ESP, EDX, destinationDisplacement: 4);
      }
      else
      {
        XS.Pop(EAX);
        XS.Or(ESP, EAX, destinationIsIndirect: true);
      }
    }
  }
}