using System;
using System.ComponentModel;
using System.Linq;
using System.Text;
using System.Text.Encodings.Web;
using System.Text.Json;
using System.Text.Json.Serialization;
using System.Text.Unicode;

namespace DPP_YH_Core.Extensions
{
    public static class ObjectExtension
    {
        private class DateTimeConverter : JsonConverter<DateTime>
        {
            public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
            {
                return DateTime.Parse(reader.GetString());
            }

            public override void Write(Utf8JsonWriter writer, DateTime value, JsonSerializerOptions options)
            {
                writer.WriteStringValue(value.ToString("yyyy-MM-dd HH:mm:ss"));
            }
        }
        /// <summary>
        /// <para>对象转JsonString</para>
        /// <para>如果对象本身是String类型则直接返回</para>
        /// </summary>
        /// <param name="obj">对象</param>
        /// <param name="formarting">是否开启格式化,格式化会多占用一些字节,默认不格式化</param>
        /// <returns></returns>
        public static string ToJsonStr(this object obj, bool formarting = false)
        {
            if (obj == null) return "";
            if (obj.GetType() == typeof(string)) return obj as string;
            if (obj.GetType() == typeof(StringBuilder)) return ((StringBuilder)obj).ToString();
            var options = new JsonSerializerOptions
            {
                WriteIndented = formarting,
                IncludeFields = true,
                DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
            };
            options.Converters.Add(new DateTimeConverter());//yyyy-MM-dd HH:mm:ss
                                                            //不加这句非ASCII字符会被序列化为Unicode编号，类似于\u8C03
            options.Encoder = JavaScriptEncoder.Create(UnicodeRanges.All);
            options.GetConverter(obj.GetType());
            var res = JsonSerializer.Serialize(obj, options);
            return res;
        }

        public static string ToNewtonJsonStr(this object obj)
        {
            return Newtonsoft.Json.JsonConvert.SerializeObject(obj);
        }

        public static T ToJson<T>(this string obj)
        {
            return Newtonsoft.Json.JsonConvert.DeserializeObject<T>(obj);
        }
        public static T To<T>(this Object @this)
        {
            if (@this != null)
            {
                Type targetType = typeof(T);

                if (@this.GetType() == targetType)
                {
                    return (T)@this;
                }

                TypeConverter converter = TypeDescriptor.GetConverter(@this);
                if (converter != null)
                {
                    if (converter.CanConvertTo(targetType))
                    {
                        return (T)converter.ConvertTo(@this, targetType);
                    }
                }

                converter = TypeDescriptor.GetConverter(targetType);
                if (converter != null)
                {
                    if (converter.CanConvertFrom(@this.GetType()))
                    {
                        return (T)converter.ConvertFrom(@this);
                    }
                }

                if (@this == DBNull.Value)
                {
                    return (T)(object)null;
                }
            }

            return (T)@this;
        }

        public static object To(this Object @this, Type type)
        {
            if (@this != null)
            {
                Type targetType = type;

                if (@this.GetType() == targetType)
                {
                    return @this;
                }

                TypeConverter converter = TypeDescriptor.GetConverter(@this);
                if (converter != null)
                {
                    if (converter.CanConvertTo(targetType))
                    {
                        return converter.ConvertTo(@this, targetType);
                    }
                }

                converter = TypeDescriptor.GetConverter(targetType);
                if (converter != null)
                {
                    if (converter.CanConvertFrom(@this.GetType()))
                    {
                        return converter.ConvertFrom(@this);
                    }
                }

                if (@this == DBNull.Value)
                {
                    return null;
                }
            }

            return @this;
        }


        /// <summary>
        /// <para>将源对象的属性值映射到target对象上,(target==null时直接返回)</para>
        /// <para>该方法使用反射</para>
        /// <para>源对象和目标对象可以是不同对象,只要属性名称一致即可,如Model1映射到Model2</para>
        /// </summary>
        /// <typeparam name="T">target泛型类</typeparam>
        /// <param name="obj">源对象</param>
        /// <param name="target">目标对象</param>
        public static void MapTo<T>(this object obj, T target) where T : class, new()
        {
            if (obj == null || target == null) return;
            var objProps = obj.GetType().GetProperties();
            if (objProps == null || objProps.Length == 0) return;
            var listObjProps = objProps.ToList();
            //var str = JsonConvert.SerializeObject(obj);
            //var foo = JsonConvert.DeserializeObject<T>(str);
            var props = typeof(T).GetProperties();
            foreach (var item in props)
            {
                if (!item.CanWrite) continue;
                var find = listObjProps.Find(p => p.Name == item.Name);
                if (find == null) continue;


                var value = find.GetValue(obj);
                if (value == null) continue;
                if (item.PropertyType != value.GetType() && !item.PropertyType.Name.Contains("Nullable"))
                {
                    value = Convert.ChangeType(value, item.PropertyType);
                }
                item.SetValue(target, value);
            }
        }
        /// <summary>
        /// <para>将源对象的映射为一个新对象</para>
        /// <para>该方法使用json序列化,对象嵌套深度不能超过8层</para>
        /// <para>源对象和目标对象可以是不同对象,只要属性名称一致即可,如Model1映射到Model2</para>
        /// </summary>
        /// <typeparam name="T">返回对象泛型类型</typeparam>
        /// <param name="obj">源对象</param>
        /// <returns></returns>
        public static T MapTo<T>(this object obj)
        {
            string str;
            JsonSerializerOptions options = null;
            if (obj == null)
                str = "";
            else if (obj.GetType() == typeof(string))
                str = obj.ToString();
            else if (obj.GetType() == typeof(StringBuilder))
                str = ((StringBuilder)obj).ToString();
            else
            {
                options = new JsonSerializerOptions
                {
                    WriteIndented = false,
                    IncludeFields = true,
                    DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
                };
                options.Converters.Add(new DateTimeConverter());//yyyy-MM-dd HH:mm:ss
                options.Encoder = JavaScriptEncoder.Create(UnicodeRanges.All);
                str = JsonSerializer.Serialize(obj, options);
            }
            if (options == null)
            {
                options = new JsonSerializerOptions
                {
                    WriteIndented = false,
                    IncludeFields = true,
                    DefaultIgnoreCondition = JsonIgnoreCondition.WhenWritingNull
                };
                options.Converters.Add(new DateTimeConverter());//yyyy-MM-dd HH:mm:ss
                options.Encoder = JavaScriptEncoder.Create(UnicodeRanges.All);
            }
            if (string.IsNullOrWhiteSpace(str)) return default;
            var res = JsonSerializer.Deserialize<T>(str, options);
            return res;
        }
        //public static T MapTo<T>(this object obj) where T: class,new()
        //{
        //    if (obj == null) return null;
        //    var objProps = obj.GetType().GetProperties();
        //    if (objProps == null || objProps.Length == 0) return null;
        //    T t = new T();
        //    obj.MapTo(t);
        //    return t;
        //}
    }
}