// ==++==
// 
//   Copyright (c) Microsoft Corporation.  All rights reserved.
// 
// ==--==
 
// Note: If you add a new ctor overloads you need to update ParameterInfo.RawDefaultValue
 
using System.Reflection;
using System.Diagnostics.Contracts;
using System.Collections.Generic;
 
namespace System.Runtime.CompilerServices
{
    [Serializable]
    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Parameter, Inherited=false)]
    [System.Runtime.InteropServices.ComVisible(true)]
    public sealed class DecimalConstantAttribute : Attribute
    {
        [CLSCompliant(false)]
        public DecimalConstantAttribute(
            byte scale,
            byte sign,
            uint hi,
            uint mid,
            uint low
        )
        {
            dec = new System.Decimal((int) low, (int)mid, (int)hi, (sign != 0), scale);
        }
 
        public DecimalConstantAttribute(
            byte scale,
            byte sign,
            int hi,
            int mid,
            int low
        )
        {
            dec = new System.Decimal(low, mid, hi, (sign != 0), scale);
        }
 
 
        public System.Decimal Value
        {
            get
            {
                return dec;
            }
        }
 
        internal static Decimal GetRawDecimalConstant(CustomAttributeData attr)
        {
            Contract.Requires(attr.Constructor.DeclaringType == typeof(DecimalConstantAttribute));
 
            foreach (CustomAttributeNamedArgument namedArgument in attr.NamedArguments)
            {
                if (namedArgument.MemberInfo.Name.Equals("Value"))
                {
                    // This is not possible because Decimal cannot be represented directly in the metadata.
                    Contract.Assert(false, "Decimal cannot be represented directly in the metadata.");
                    return (Decimal)namedArgument.TypedValue.Value;
                }
            }
 
            ParameterInfo[] parameters = attr.Constructor.GetParameters();
            Contract.Assert(parameters.Length == 5);
 
            System.Collections.Generic.IList<CustomAttributeTypedArgument> args = attr.ConstructorArguments;
            Contract.Assert(args.Count == 5);
 
            if (parameters[2].ParameterType == typeof(uint))
            {
                // DecimalConstantAttribute(byte scale, byte sign, uint hi, uint mid, uint low)
                int low = (int)(UInt32)args[4].Value;
                int mid = (int)(UInt32)args[3].Value;
                int hi = (int)(UInt32)args[2].Value;
                byte sign = (byte)args[1].Value;
                byte scale = (byte)args[0].Value;
 
                return new System.Decimal(low, mid, hi, (sign != 0), scale);
            }
            else
            {
                // DecimalConstantAttribute(byte scale, byte sign, int hi, int mid, int low)
                int low = (int)args[4].Value;
                int mid = (int)args[3].Value;
                int hi = (int)args[2].Value;
                byte sign = (byte)args[1].Value;
                byte scale = (byte)args[0].Value;
 
                return new System.Decimal(low, mid, hi, (sign != 0), scale);
            }
        }
 
        private System.Decimal dec;
    }
}