using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.Linq;
using System.Reflection;

namespace Muchinfo.PC.Common.Extensions
{
    public static class EnumerableExtensions
    {
        /// <summary>
        /// To the observable collection.
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="source">The source.</param>
        /// <returns>ObservableCollection{``0}.</returns>
        public static ObservableCollection<T> ToObservableCollection<T>(this IEnumerable<T> source)
        {
            return source == null ? null : new ObservableCollection<T>(source);
        }

        /// <summary>
        /// Order By 扩展
        /// </summary>
        /// <typeparam name="T"></typeparam>
        /// <param name="list">The list.</param>
        /// <param name="sortField">The sort field.</param>
        /// <param name="sortDirection">The sort direction.</param>
        /// <returns>IEnumerable{``0}.</returns>
        public static IEnumerable<T> OrderBy<T>(this IEnumerable<T> list, string sortField, string sortDirection = "asc")
        {
            try
            {
                if (string.IsNullOrWhiteSpace(sortField.Trim())) return list;

                PropertyInfo prop = typeof(T).GetProperty(sortField.Trim());
                if (prop == null)
                {
                    return list;
                }
                var descending = sortDirection.Trim().ToLower() == "desc";
                return descending ? list.OrderByDescending(x => prop.GetValue(x, null)) : list.OrderBy(x => prop.GetValue(x, null));
            }
            catch
            {
                return list;
            }
        }
    }
}