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

namespace CSFramework.WebApi.Utils
{
    /// <summary>
    /// 对象操作类
    /// </summary>
    public static class ObjectHelper
    {

        /// <summary>
        /// 复制对象, 仅复制对象相同属性的值. 
        /// </summary>
        /// <param name="source">对象实例</param>
        /// <param name="ignoreCase">对象属性名称匹配忽略大小写</param>
        /// <returns></returns>
        public static TOut Clone<TIn, TOut>(TIn source, bool ignoreCase = true)
        {
            try
            {
                if (source == null) return default(TOut);

                Type objTypeIn = typeof(TIn);
                Type objTypeOut = typeof(TOut);

                PropertyInfo[] propsIn = objTypeIn.GetProperties();
                PropertyInfo[] propsOut = objTypeOut.GetProperties();

                //返回的对象实例
                TOut destObj = (TOut)objTypeOut.Assembly.CreateInstance(objTypeOut.FullName);

                foreach (PropertyInfo infoSource in propsIn)
                {
                    object value = infoSource.GetValue(source, null);

                    //判断相同属性名称
                    var pTarget = propsOut.Where(w => String.Compare(w.Name, infoSource.Name, ignoreCase) == 0).FirstOrDefault();

                    if (pTarget != null)
                        SetPropertyValue(destObj, pTarget, value);
                }
                return destObj;
            }
            catch
            {
                return default(TOut);
            }
        }


        /// <summary>
        /// 给对象的属性赋值
        /// </summary>
        /// <param name="instance">对象实例</param>
        /// <param name="prop">对象实例的属性信息</param>
        /// <param name="value">其他对象属性的值</param>
        public static void SetPropertyValue(object instance, PropertyInfo prop, object value)
        {
            try
            {
                if (prop == null) return;

                if (prop.PropertyType.IsArray)//数组类型,单独处理
                {
                    if (value == DBNull.Value)//特殊处理DBNull类型
                        prop.SetValue(instance, null, null);
                    else
                        prop.SetValue(instance, value, null);
                }
                else
                {
                    if (value == null || String.IsNullOrWhiteSpace(value.ToString()))//空值
                        value = prop.PropertyType.IsValueType ? Activator.CreateInstance(prop.PropertyType) : null;//值类型
                    else
                        value = System.ComponentModel.TypeDescriptor.GetConverter(prop.PropertyType).ConvertFromString(value.ToString());//创建对象

                    prop.SetValue(instance, value, null);
                }
            }
            catch (Exception ex)
            {
                //报错在此跟踪
            }
        }

    }


}