using IRaCIS.Core.Infrastructure.NewtonsoftJson;
using Newtonsoft.Json;
using Newtonsoft.Json.Serialization;
using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;
using System.Linq;
using System.Reflection;
using System.Reflection.Metadata;

namespace IRaCIS.Core.API
{
    /// <summary>
    /// LowerCamelCaseJsonAttribute 可以设置类小写返回给前端
    /// </summary>
    public class NullToEmptyStringResolver : DefaultContractResolver
    {

        protected override IList<JsonProperty> CreateProperties(Type type, MemberSerialization memberSerialization)
        {
            // 检查类是否有 LowerCamelCaseJsonAttribute 标记  有的话，属性名小写
            if (type.GetCustomAttribute<LowerCamelCaseJsonAttribute>() != null)
            {
                base.NamingStrategy = new LowerCamelCaseNamingStrategy();
            }
            else
            {
                base.NamingStrategy = null;
            }


            IList<JsonProperty> properties = base.CreateProperties(type, memberSerialization);


            var list = type.GetProperties()
                .Select(p =>
                {
                    var jp = base.CreateProperty(p, memberSerialization);
                    jp.ValueProvider = new NullToEmptyStringValueProvider(p);
                    return jp;
                }).ToList();

            var uu = list.Select(t => t.PropertyName).ToList();

            //获取复杂对象属性
            properties = properties.TakeWhile(t => !uu.Contains(t.PropertyName)).ToList();

            list.AddRange(properties);
            return list;
        }


    }
    public class NullToEmptyStringValueProvider : IValueProvider
    {
        PropertyInfo _memberInfo;
        private readonly bool _isNullable;
        public NullToEmptyStringValueProvider(PropertyInfo memberInfo)
        {
            _memberInfo = memberInfo;

        }



        // DTO → JSON 返回前端的时候 处理null 变为"" 方便前端判断
        public object GetValue(object target)
        {
            var result = _memberInfo.GetValue(target);
            // 检查类型是否为string或string?
            if (_memberInfo.PropertyType == typeof(string) && result == null)
            {

                #region 返回的时候处理 string string? null 为"" 不区分处理


                //// 如果是string?类型，返回null  可以做到，但是得反射，因为 string string? 是编译层区分的

                //var isNullable1 = _memberInfo.CustomAttributes
                //   .Any(a => a.AttributeType.Name == "NullableAttribute");

                ////var isNullable2 = _memberInfo.CustomAttributes
                ////   .Any(a => a.AttributeType.FullName == "System.Runtime.CompilerServices.NullableAttribute");

                //if (isNullable1)
                //{
                //    return result;
                //}

                #endregion


                // 如果是string类型，返回空字符串
                return string.Empty;
            }
            return result;
        }


        //影响 模型绑定时接收前端的值，同时影响 正常 JSON 序列化
        public void SetValue(object target, object value)
        {



            //// 会影响 string?  传递null 变为""

            var isNullable1 = _memberInfo.CustomAttributes.Any(a => a.AttributeType.Name == "NullableAttribute");


            if (_memberInfo.PropertyType == typeof(string) &&  isNullable1 == false)
            {
                //如果不处理 前段传递null  string不会接收，说前段没传递会验证报错
                _memberInfo.SetValue(target, value == null ? string.Empty : value);
            }
            else
            {
                _memberInfo.SetValue(target, value);

            }

            //if ()
            //{
            //    //去掉前后空格
            //    _memberInfo.SetValue(target, value == null ? string.Empty : value.ToString() == string.Empty ? value : value/*.ToString().Trim()*/);
            //}
            //else
            //{
            //    _memberInfo.SetValue(target, value);
            //}


        }
    }
}