using Newtonsoft.Json;
using System;
using System.Globalization;

namespace YLErp.Converter2
{
    public class IsoDateTimeConverterNullable : JsonConverter<DateTime?>
    {
        public IsoDateTimeConverterNullable() { }
        public IsoDateTimeConverterNullable(string format)
        {
            DateTimeFormat = format;
        }
        public string DateTimeFormat { get; set; } = "yyyy/MM/dd";

        public override DateTime? ReadJson(JsonReader reader, Type objectType, DateTime? existingValue, bool hasExistingValue, JsonSerializer serializer)
        {

            if (string.IsNullOrWhiteSpace(reader.Value?.ToString()) && (Nullable.GetUnderlyingType(objectType) != null))
            {
                return null;
            }
            DateTime date;
            try
            {
                date = DateTime.ParseExact(reader.Value?.ToString(), DateTimeFormat, CultureInfo.InvariantCulture);
            }
            catch (Exception)
            {
                date = DateTime.Parse(reader.Value?.ToString());
            }

            return date;
        }

        public override void WriteJson(JsonWriter writer, DateTime? value, JsonSerializer serializer)
        {
            if (!value.HasValue)
            {
                writer.WriteNull();
            }
            else
            {
                writer.WriteValue(value.Value.ToString(DateTimeFormat));
            }
        }
    }
}