using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Linq;
using System.Reflection;
using System.Text;
using System.Threading.Tasks;

namespace Services.Extensions
{
    /// <summary>
    /// 对象扩展
    /// </summary>
    public static class ModelExtensions
    {
        /// <summary>
        /// 创建一个新的类型的对象，并将现有对象的属性值赋给新对象相同名称的属性
        /// </summary>
        /// <typeparam name="T">新对象的类型</typeparam>
        /// <param name="source">现有对象</param>
        /// <returns>新的对象</returns>
        public static T ToModel<T>(this object source) where T : new()
        {
            if (source == null)
            {
                return default(T);
            }
            return Activator.CreateInstance<T>().UpdateFrom(source, new string[0]);
        }

        /// <summary>
        /// 将源对象的属性值赋给目标对象相同名称的属性
        /// </summary>
        /// <typeparam name="T">目标类型</typeparam>
        /// <param name="target">目标对象</param>
        /// <param name="source">源对象</param>
        /// <param name="copyPropertyName">需要复制的属性名,为空时表示复制全部</param>
        /// <returns>目标类型</returns>
        public static T UpdateFrom<T>(this T target, object source, params string[] copyPropertyName)
        {
            if (target == null)
            {
                return default(T);
            }
            if (source == null)
            {
                return target;
            }
            Type typeFromHandle = typeof(T);
            foreach (PropertyInfo obj in source.GetType().GetProperties())
            {
                //PropertyDescriptor propertyDescriptor = (PropertyDescriptor)obj;
                if (copyPropertyName == null || copyPropertyName.Length == 0 || copyPropertyName.Contains(obj.Name))
                {
                    PropertyInfo property = typeFromHandle.GetProperty(obj.Name, BindingFlags.Instance | BindingFlags.Public);
                    if (property != null && property.CanWrite)
                    {
                        property.SetValue(target, obj.GetValue(source, null), null);
                    }
                }
            }
            return target;
        }
    }

}