///////////////////////////////////////////////////////////////////////////////
//Copyright (c) 2016, 北京探索者软件公司
//All rights reserved.       
//文件名称: EnumToEnumItemConverter.cs
//文件描述: 枚举向枚举条目对象转换
//创 建 者: xls
//创建日期: 2018-1-23
//版 本 号：1.0.0.0
////////////////////////////////////////////////////////////////////////////////

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Data;
using FWindSoft.SystemExtensions;


namespace FWindSoft.Wpf
{
    public class EnumToEnumItemConverter : IValueConverter
    {
        public static EnumToEnumItemConverter Instance = new EnumToEnumItemConverter();
        public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            Type sourceType = value.GetType();
            if (!sourceType.IsEnum)
                return value;
            var enumerable = parameter as IEnumerable<Object>;
            if (enumerable == null)
                return value;
            if (targetType.GetGenericTypeDefinition().FullName!=typeof (EnumItem<>).FullName)
            {
                return value;
            }
            var anyItem = enumerable.FirstOrDefault();
            if (anyItem == null)
            {
                return value;
            }
            var anyType = anyItem.GetType();
            if (!anyType.IsGenericType)
            {
                return value;
            }
            if (anyType.GetGenericArguments()[0] != sourceType)
            {
                return value;
            }
            var property=anyType.GetProperty("Item",
                   System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public);
            if (property == null)
            {
                return value;
            }
            foreach (var o in enumerable)
            {
                if (
                    System.Convert.ChangeType(property.GetValue(0), sourceType)
                        .Equals(System.Convert.ChangeType(value, sourceType)))
                {
                    return o;
                }
            }
            return value;

        }

        public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
        {
            var anyType = value.GetType();
            if (!anyType.IsGenericType)
            {
                return value;
            }
            if (anyType.GetGenericArguments()[0] != targetType)
            {
                return value;
            }
            var property = anyType.GetProperty("Item",
                   System.Reflection.BindingFlags.Instance | System.Reflection.BindingFlags.Public);
            if (property == null)
            {
                return value;
            }
            return System.Convert.ChangeType(property.GetValue(value), targetType);
        }
    }
}