using System;
using CPUx86 = Cosmos.Assembler.x86;
using CPU = Cosmos.Assembler.x86;
using Cosmos.Assembler.x86;
using Cosmos.Assembler;
using Cosmos.Assembler.x86.x87;
using XSharp.Compiler;

namespace Cosmos.IL2CPU.X86.IL
{
    [Cosmos.IL2CPU.OpCode( ILOpCode.Code.Clt_Un )]
    public class Clt_Un : ILOp
    {
        public Clt_Un( 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 )
            {
                throw new NotImplementedException("Cosmos.IL2CPU.x86->IL->Clt_Un.cs->Error: StackSizes > 8 not supported");
            }
            string BaseLabel = GetLabel( aMethod, aOpCode ) + ".";
            string LabelTrue = BaseLabel + "True";
            string LabelFalse = BaseLabel + "False";
            if( xStackItemSize > 4 )
            {
				new CPUx86.Mov { DestinationReg = CPUx86.RegistersEnum.ESI, SourceValue = 1 };
				// esi = 1
				XS.Xor(XSRegisters.OldToNewRegister(RegistersEnum.EDI), XSRegisters.OldToNewRegister(RegistersEnum.EDI));
				// edi = 0
                if (xStackItemIsFloat)
                {
					// value 2
					new FloatLoad { DestinationReg = RegistersEnum.ESP, Size = 64, DestinationIsIndirect = true };
					// value 1
					new FloatLoad { DestinationReg = RegistersEnum.ESP, Size = 64, DestinationDisplacement = 8, DestinationIsIndirect = true };
					new FloatCompareAndSet { DestinationReg = RegistersEnum.ST1 };
					// if carry is set, ST(0) < ST(i)
					new ConditionalMove { Condition = ConditionalTestEnum.Below, DestinationReg = RegistersEnum.EDI, SourceReg = RegistersEnum.ESI };
					// pops fpu stack
					new FloatStoreAndPop { DestinationReg = RegistersEnum.ST0 };
					new FloatStoreAndPop { DestinationReg = RegistersEnum.ST0 };
					new CPUx86.Add { DestinationReg = RegistersEnum.ESP, SourceValue = 16 };
				}
                else
                {
                    new CPUx86.Pop { DestinationReg = RegistersEnum.EAX };
                    new CPUx86.Pop { DestinationReg = RegistersEnum.EDX };
                    //value2: EDX:EAX
                    new CPUx86.Pop { DestinationReg = RegistersEnum.EBX };
                    new CPUx86.Pop { DestinationReg = RegistersEnum.ECX };
                    //value1: ECX:EBX
                    XS.Sub(XSRegisters.OldToNewRegister(RegistersEnum.EBX), XSRegisters.OldToNewRegister(RegistersEnum.EAX));
                    XS.SubWithCarry(XSRegisters.OldToNewRegister(RegistersEnum.ECX), XSRegisters.OldToNewRegister(RegistersEnum.EDX));
                    //result = value1 - value2
					new CPUx86.ConditionalMove { Condition = CPUx86.ConditionalTestEnum.Below, DestinationReg = CPUx86.RegistersEnum.EDI, SourceReg = CPUx86.RegistersEnum.ESI };
                }
                new CPUx86.Push { DestinationReg = CPUx86.RegistersEnum.EDI };
            }
            else
            {
                if (xStackItemIsFloat)
                {
                	#warning THIS NEEDS TO BE TESTED!!!
					new Comment("TEST TODO");
                    new CPUx86.SSE.MoveSS { DestinationReg = CPUx86.RegistersEnum.XMM0, SourceReg = CPUx86.RegistersEnum.ESP, SourceIsIndirect = true };
                    new CPUx86.Add { DestinationReg = CPUx86.RegistersEnum.ESP, SourceValue = 4 };
                    new CPUx86.SSE.MoveSS { DestinationReg = CPUx86.RegistersEnum.XMM1, SourceReg = CPUx86.RegistersEnum.ESP, SourceIsIndirect = true };
					new CPUx86.SSE.CompareSS { DestinationReg = CPUx86.RegistersEnum.XMM1, SourceReg = CPUx86.RegistersEnum.XMM0, pseudoOpcode = (byte)CPUx86.SSE.ComparePseudoOpcodes.LessThan };
                    new CPUx86.SSE.MoveSS { DestinationReg = CPUx86.RegistersEnum.ESP, DestinationIsIndirect = true, SourceReg = CPUx86.RegistersEnum.XMM1 };
                    new CPUx86.And { DestinationReg = CPUx86.RegistersEnum.ESP, DestinationIsIndirect = true, SourceValue = 1 };
                }
                else
                {
                    new CPUx86.Pop { DestinationReg = CPUx86.RegistersEnum.ECX };
                    new CPUx86.Pop { DestinationReg = CPUx86.RegistersEnum.EAX };
                    new CPUx86.Push { DestinationReg = CPUx86.RegistersEnum.ECX };
                    new CPUx86.Compare { DestinationReg = CPUx86.RegistersEnum.EAX, SourceReg = CPUx86.RegistersEnum.ESP, SourceIsIndirect = true };
                    new CPUx86.ConditionalJump { Condition = CPUx86.ConditionalTestEnum.Below, DestinationLabel = LabelTrue };
                    new CPUx86.Jump { DestinationLabel = LabelFalse };
                    new Label( LabelTrue );
                    new CPUx86.Add { DestinationReg = CPUx86.RegistersEnum.ESP, SourceValue = 4 };
                    new CPUx86.Push { DestinationValue = 1 };
                    new CPUx86.Jump { DestinationLabel = GetLabel(aMethod, aOpCode.NextPosition) };
                    new Label( LabelFalse );
                    new CPUx86.Add { DestinationReg = CPUx86.RegistersEnum.ESP, SourceValue = 4 };
                    new CPUx86.Push { DestinationValue = 0 };
            }
            }
        }

    }
}