using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Markup;

namespace MECF.Framework.UI.Client.CenterViews.Maintain
{
    public class EnumBindingSourceExtension : MarkupExtension
    {
        private Type _enumType;

        public Type EnumType
        {
            get { return _enumType; }
            set
            {
                if (value != _enumType)
                {
                    if (null != value)
                    {
                        var enumType = Nullable.GetUnderlyingType(value) ?? value;
                        if (!enumType.IsEnum)
                        {
                            throw new ArgumentException("Type must bu for an Enum");
                        }

                    }

                    _enumType = value;
                }
            }
        }

        public EnumBindingSourceExtension()
        {

        }

        public EnumBindingSourceExtension(Type enumType)
        {
            EnumType = enumType;
        }
        public override object ProvideValue(IServiceProvider serviceProvider)
        {
            if (null == _enumType)
            {
                throw new InvalidOperationException("The EnumTYpe must be specified.");
            }

            var actualEnumType = Nullable.GetUnderlyingType(_enumType) ?? _enumType;
            var enumValues = Enum.GetValues(actualEnumType);

            if (actualEnumType == _enumType)
            {
                return enumValues;
            }

            var tempArray = Array.CreateInstance(actualEnumType, enumValues.Length + 1);
            enumValues.CopyTo(tempArray, 1);

            return tempArray;
        }
    }
}