using System;
using System.Text;

#if NETCF_1_0 || NETCF_2_0 || SILVERLIGHT
using System.Collections;
using System.Reflection;
#endif

using Org.BouncyCastle.Utilities.Date;

namespace Org.BouncyCastle.Utilities
{
    internal sealed class Enums
    {
        private Enums()
        {
        }

		internal static Enum GetEnumValue(System.Type enumType, string s)
		{
			if (!enumType.IsEnum)
				throw new ArgumentException("Not an enumeration type", "enumType");

			// We only want to parse single named constants
			if (s.Length > 0 && char.IsLetter(s[0]) && s.IndexOf(',') < 0)
			{
				s = s.Replace('-', '_');

#if NETCF_1_0
				FieldInfo field = enumType.GetField(s, BindingFlags.Static | BindingFlags.Public);
				if (field != null)
				{
					return (Enum)field.GetValue(null);
				}
#else
				return (Enum)Enum.Parse(enumType, s, false);
#endif		
			}

			throw new ArgumentException();
		}

		internal static Array GetEnumValues(System.Type enumType)
		{
			if (!enumType.IsEnum)
				throw new ArgumentException("Not an enumeration type", "enumType");

#if NETCF_1_0 || NETCF_2_0 || SILVERLIGHT
            IList result = Platform.CreateArrayList();
			FieldInfo[] fields = enumType.GetFields(BindingFlags.Static | BindingFlags.Public);
			foreach (FieldInfo field in fields)
			{
                // Note: Argument to GetValue() ignored since the fields are static,
                //     but Silverlight for Windows Phone throws exception if we pass null
				result.Add(field.GetValue(enumType));
			}
            object[] arr = new object[result.Count];
            result.CopyTo(arr, 0);
            return arr;
#else
			return Enum.GetValues(enumType);
#endif
		}

		internal static Enum GetArbitraryValue(System.Type enumType)
		{
			Array values = GetEnumValues(enumType);
			int pos = (int)(DateTimeUtilities.CurrentUnixMs() & int.MaxValue) % values.Length;
			return (Enum)values.GetValue(pos);
		}
	}
}
