using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Text;

namespace Cosmos.Assembler.x86
{
    public static class InfraExtensions
    {
        public static string GetDestinationAsString(this IInstructionWithDestination aThis)
        {
            string xDest = string.Empty;
            if ((aThis.DestinationValue.HasValue || aThis.DestinationRef != null) &&
                aThis.DestinationIsIndirect &&
                aThis.DestinationReg != null && aThis.DestinationDisplacement > 0)
            {
                throw new Exception("[Scale*index+base] style addressing not supported at the moment");
            }
            if (aThis.DestinationRef != null)
            {
                xDest = aThis.DestinationRef.ToString();
            }
            else
            {
                if (aThis.DestinationReg != null)
                {
                    xDest = Registers.GetRegisterName(aThis.DestinationReg.Value);
                }
                else
                {
                    if (aThis.DestinationValue.HasValue)
                        xDest = "0x" + aThis.DestinationValue.GetValueOrDefault().ToString("X").ToUpperInvariant();
                }
            }
            if (aThis.DestinationDisplacement != null && aThis.DestinationDisplacement != 0)
            {
                if (aThis.DestinationDisplacement > 255)
                {
                    xDest += " + 0x" + aThis.DestinationDisplacement.Value.ToString("X");
                }
                else
                {
                    xDest += (aThis.DestinationDisplacement < 0 ? " - " : " + ") + Math.Abs(aThis.DestinationDisplacement.Value);
                }
            }
            if (aThis.DestinationIsIndirect)
            {
                return "[" + xDest + "]";
            }
            return xDest;
        }

        public static void DetermineSize(this IInstructionWithDestination aThis, IInstructionWithSize aThis2, byte aSize)
        {
            if (aSize == 0)
            {
                if (aThis.DestinationReg != null && !aThis.DestinationIsIndirect)
                {
                    aThis2.Size = Registers.GetSize(aThis.DestinationReg.Value);
                    return;
                }
                if (aThis.DestinationRef != null && !aThis.DestinationIsIndirect)
                {
                    aThis2.Size = 32;
                    return;
                }
            }
        }

        public static string GetMnemonic(this ConditionalTestEnum aThis)
        {
            switch (aThis)
            {
                case ConditionalTestEnum.Overflow:
                    return "o";
                case ConditionalTestEnum.NoOverflow:
                    return "no";
                case ConditionalTestEnum.Below:
                    return "b";
                case ConditionalTestEnum.NotBelow:
                    return "nb";
                case ConditionalTestEnum.Equal:
                    return "e";
                case ConditionalTestEnum.NotEqual:
                    return "ne";
                case ConditionalTestEnum.BelowOrEqual:
                    return "be";
                case ConditionalTestEnum.NotBelowOrEqual:
                    return "nbe";
                case ConditionalTestEnum.Sign:
                    return "s";
                case ConditionalTestEnum.NotSign:
                    return "ns";
                case ConditionalTestEnum.Parity:
                    return "p";
                case ConditionalTestEnum.NotParity:
                    return "np";
                case ConditionalTestEnum.LessThan:
                    return "l";
                case ConditionalTestEnum.NotLessThan:
                    return "nl";
                case ConditionalTestEnum.LessThanOrEqualTo:
                    return "le";
                case ConditionalTestEnum.NotLessThanOrEqualTo:
                    return "nle";
                case ConditionalTestEnum.CXRegisterEqualOrZeroTo:
                    return "cxe";
                case ConditionalTestEnum.ECXRegisterEqualOrZeroTo:
                    return "ecxe";
                default:
                    throw new NotImplementedException();
            }
        }
    }
}