using System;
using Indy.IL2CPU;
using Cosmos.IL2CPU.ILOpCodes;
using CPUx86 = Cosmos.IL2CPU.X86;
using CPU = Cosmos.IL2CPU.X86;
namespace Cosmos.IL2CPU.X86.IL
{
    /// <summary>
    /// Compares two values. If the first value is less than the second, the integer value 1 (int32) is pushed onto the evaluation stack;
    /// otherwise 0 (int32) is pushed onto the evaluation stack.
    /// </summary>
    [Cosmos.IL2CPU.OpCode( ILOpCode.Code.Clt )]
    public class Clt : ILOp
    {
        public Clt( Cosmos.IL2CPU.Assembler aAsmblr )
            : base( aAsmblr )
        {
        }

        public override void Execute( MethodInfo aMethod, ILOpCode aOpCode )
        {
            var xStackItem = Assembler.Stack.Pop();
            if( xStackItem.IsFloat )
            {
                //EmitNotImplementedException( Assembler, GetServiceProvider(), "Clt: Floats not yet supported", CurInstructionLabel, mMethodInfo, mCurrentOffset, NextInstructionLabel );
                throw new NotImplementedException();
                //return;
            }
            if( xStackItem.Size > 8 )
            {
                //EmitNotImplementedException( Assembler, GetServiceProvider(), "Clt: StackSizes>8 not supported", CurInstructionLabel, mMethodInfo, mCurrentOffset, NextInstructionLabel );
                throw new NotImplementedException();
                //return;
            }
            Assembler.Stack.Push( new StackContents.Item( 1, typeof( bool ) ) );
            string BaseLabel = GetLabel( aMethod, aOpCode ) + "__";
            string LabelTrue = BaseLabel + "True";
            string LabelFalse = BaseLabel + "False";
            if( xStackItem.Size > 4 )
            {
                new CPUx86.Xor { DestinationReg = CPUx86.Registers.ESI, SourceReg = CPUx86.Registers.ESI };
                new CPUx86.Add { DestinationReg = CPUx86.Registers.ESI, SourceValue = 1 };
                new CPUx86.Xor { DestinationReg = CPUx86.Registers.EDI, SourceReg = CPUx86.Registers.EDI };
                //esi = 1
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.EDX };
                //value2: EDX:EAX
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.EBX };
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.ECX };
                //value1: ECX:EBX
                new CPUx86.Sub { DestinationReg = CPUx86.Registers.EBX, SourceReg = CPUx86.Registers.EAX };
                new CPUx86.SubWithCarry { DestinationReg = CPUx86.Registers.ECX, SourceReg = CPUx86.Registers.EDX };
                //result = value1 - value2
                new CPUx86.ConditionalMove { Condition = CPUx86.ConditionalTestEnum.LessThan, DestinationReg = CPUx86.Registers.EDI, SourceReg = CPUx86.Registers.ESI };
                new CPUx86.Push { DestinationReg = CPUx86.Registers.EDI };
            }
            else
            {
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.ECX };
                new CPUx86.Pop { DestinationReg = CPUx86.Registers.EAX };
                new CPUx86.Push { DestinationReg = CPUx86.Registers.ECX };
                new CPUx86.Compare { DestinationReg = CPUx86.Registers.EAX, SourceReg = CPUx86.Registers.ESP, SourceIsIndirect = true };
                new CPUx86.ConditionalJump { Condition = CPUx86.ConditionalTestEnum.LessThan, DestinationLabel = LabelTrue };
                new CPUx86.Jump { DestinationLabel = LabelFalse };
                new Label( LabelTrue );
                new CPUx86.Add { DestinationReg = CPUx86.Registers.ESP, SourceValue = 4 };
                new CPUx86.Push { DestinationValue = 1 };

                new CPUx86.Jump { DestinationLabel = GetLabel(aMethod, aOpCode.NextPosition) };
                
                new Label( LabelFalse );
                new CPUx86.Add { DestinationReg = CPUx86.Registers.ESP, SourceValue = 4 };
                new CPUx86.Push { DestinationValue = 0 };
            }
        }


        // using System;
        // using System.IO;
        // 
        // 
        // using CPUx86 = Cosmos.IL2CPU.X86;
        // using CPU = Cosmos.IL2CPU.X86;
        // using Cosmos.IL2CPU.X86;
        // using Cosmos.IL2CPU.X86;
        // 
        // namespace Indy.IL2CPU.IL.X86 {
        // 	[OpCode(OpCodeEnum.Clt)]
        // 	public class Clt: Op {
        // 		private readonly string NextInstructionLabel;
        // 		private readonly string CurInstructionLabel;
        //         private uint mCurrentOffset;
        //         private MethodInformation mMethodInfo;
        //         public Clt(ILReader aReader, MethodInformation aMethodInfo)
        // 			: base(aReader, aMethodInfo) {
        // 			NextInstructionLabel = GetInstructionLabel(aReader.NextPosition);
        // 			CurInstructionLabel = GetInstructionLabel(aReader);
        //             mMethodInfo = aMethodInfo;
        //             mCurrentOffset = aReader.Position;
        // 		}
        // 		public override void DoAssemble() {

        // 		}
        // 	}
        // }

    }
}