using System.Text.Json;

namespace OASystem.API.OAMethodLib
{
    #region 日期格式转换("yyyy-MM-dd HH;mm:ss")

    public class DateTimeJsonConverter : System.Text.Json.Serialization.JsonConverter<DateTime>
    {
        private readonly string Format;
        public DateTimeJsonConverter(string format)
        {
            Format = format;
        }

        public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (string.IsNullOrEmpty(reader.GetString()))
            {
                return default(DateTime);
            }

            return DateTime.ParseExact(reader.GetString(), Format, null);
        }

        public override void Write(Utf8JsonWriter writer, DateTime date, JsonSerializerOptions options)
        {
            writer.WriteStringValue(date.ToString(Format));
        }
        //public override DateTime Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        //{
        //    return DateTime.ParseExact(reader.GetString(), Format, null);
        //}
    }
    #endregion

    #region String null值转换（读/写）


    public class NullJsonConverter : System.Text.Json.Serialization.JsonConverter<string>
    {
        public override bool HandleNull => true;

        public override string Read(
            ref Utf8JsonReader reader,
            Type typeToConvert,
            JsonSerializerOptions options) =>
            reader.GetString() ?? "";

        public override void Write(
            Utf8JsonWriter writer,
            string value,
            JsonSerializerOptions options) =>
            writer.WriteStringValue(value ?? "");

    }

    #endregion


    #region decimal格式化 decimalPlaces=3 应用自定义的序列化器，并指定小数位数为 3
    public class DecimalConverter : System.Text.Json.Serialization.JsonConverter<decimal>
    {
        private readonly int decimalPlaces;

        public DecimalConverter(int decimalPlaces = 2)
        {
            this.decimalPlaces = decimalPlaces;
        }

        public override decimal Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType == JsonTokenType.Number)
                return reader.GetDecimal();
            else
                throw new System.Text.Json.JsonException();
        }

        public override void Write(Utf8JsonWriter writer, decimal value, JsonSerializerOptions options)
        {
            string formatString = "0." + new string('0', decimalPlaces);
            string formattedValue = value.ToString(formatString); // 格式化字符串，保留指定位数的小数
            writer.WriteStringValue(formattedValue);
        }
    }

    #endregion

}