using System;
using CPUx86 = Cosmos.Assembler.x86;
using CPU = Cosmos.Assembler.x86;
using Cosmos.Assembler.x86;
using Cosmos.Assembler;
using Cosmos.Assembler.x86.SSE;
using Cosmos.Assembler.x86.x87;
using XSharp.Compiler;
using static XSharp.Compiler.XSRegisters;
using static Cosmos.Assembler.x86.SSE.ComparePseudoOpcodes;

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

		public override void Execute( MethodInfo aMethod, ILOpCode aOpCode )
		{
            var xStackItem = aOpCode.StackPopTypes[0];
            var xStackItemSize = SizeOfType(xStackItem);
            var xStackItemIsFloat = TypeIsFloat(xStackItem);
			if( xStackItemSize > 8 )
			{
				//EmitNotImplementedException( Assembler, GetServiceProvider(), "Cgt: StackSizes>8 not supported", CurInstructionLabel, mMethodInfo, mCurrentOffset, NextInstructionLabel );
				throw new NotImplementedException("Cosmos.IL2CPU.x86->IL->Cgt.cs->Error: StackSizes > 8 not supported");
				//return;
			}
			string BaseLabel = GetLabel( aMethod, aOpCode ) + ".";
			string LabelTrue = BaseLabel + "True";
			string LabelFalse = BaseLabel + "False";
			var xNextLabel = GetLabel(aMethod, aOpCode.NextPosition);
			if( xStackItemSize > 4 )
			{
                // Using SSE registers (that do NOT branch!) This is needed only for long now
#if false
				XS.Set(XSRegisters.ESI, 1);
				// esi = 1
				XS.Xor(XSRegisters.EDI, XSRegisters.EDI);
				// edi = 0
#endif
				if (xStackItemIsFloat)
				{
                    // Please note that SSE supports double operations only from version 2
                    XS.SSE2.MoveSD(XMM0, ESP, sourceIsIndirect: true);
                    // Increment ESP to get the value of the next double
                    XS.Add(ESP, 8);
                    XS.SSE2.MoveSD(XMM1, ESP, sourceIsIndirect: true);
                    XS.SSE2.CompareSD(XMM1, XMM0, comparision: NotLessThanOrEqualTo);
                    XS.SSE2.MoveD(EBX, XMM1);
                    XS.And(EBX, 1);
                    // We need to move the stack pointer of 4 Byte to "eat" the second double that is yet in the stack or we get a corrupted stack!
                    XS.Add(ESP, 4);
                    XS.Set(ESP, EBX, destinationIsIndirect: true);
                }
				else
				{
                    XS.Set(ESI, 1);
                    // esi = 1
                    XS.Xor(EDI, EDI);
                    // edi = 0
                    XS.Pop(EAX);
					XS.Pop(EDX);

					//value2: EDX:EAX
					XS.Pop(EBX);
					XS.Pop(ECX);
					//value1: ECX:EBX
					XS.Compare(ECX, EDX);
					XS.Jump(ConditionalTestEnum.GreaterThan, LabelTrue);
					XS.Jump(ConditionalTestEnum.LessThan, LabelFalse);
					XS.Compare(EBX, EAX);
					XS.Label(LabelTrue);
					new ConditionalMove { Condition = ConditionalTestEnum.GreaterThan, DestinationReg = RegistersEnum.EDI, SourceReg = RegistersEnum.ESI };
					XS.Label(LabelFalse);
                    XS.Push(EDI);
                }
				/*
				XS.Jump(ConditionalTestEnum.GreaterThan, LabelTrue);
				XS.Label(LabelFalse);
				XS.Push(0);
				XS.Jump(xNextLabel);
				XS.Label(LabelTrue );
				XS.Push(1);*/
			}
			else
			{
				if (xStackItemIsFloat){
					XS.SSE.MoveSS(XMM0, ESP, sourceIsIndirect: true);
					XS.Add(XSRegisters.ESP, 4);
					XS.SSE.MoveSS(XMM1, ESP, sourceIsIndirect: true);
                    XS.SSE.CompareSS(XMM1, XMM0, comparision: NotLessThanOrEqualTo);
                    XS.SSE2.MoveD(EBX, XMM1);
                    XS.And(XSRegisters.EBX, 1);
					XS.Set(ESP, EBX, destinationIsIndirect: true);
				}

				else{
					XS.Pop(EAX);
					XS.Compare(EAX, ESP, sourceIsIndirect: true);
					XS.Jump(ConditionalTestEnum.LessThan, LabelTrue);
					XS.Jump(LabelFalse);
					XS.Label(LabelTrue );
					XS.Add(XSRegisters.ESP, 4);
					XS.Push(1);
					XS.Jump(xNextLabel);
					XS.Label(LabelFalse );
					XS.Add(XSRegisters.ESP, 4);
					XS.Push(0);
				}
			}
		}
	}
}