using System;
using Newtonsoft.Json;
using Newtonsoft.Json.Linq;

namespace ChatController.LoginKlassen
{
    public class TimeStampConverter : JsonConverter
    {
        public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
        {
            throw new NotImplementedException("Nicht implementiert, da nicht benötigt.");
        }

        public override object ReadJson(JsonReader reader, Type objectType, object messageJson, JsonSerializer serializer)
        {
            switch(reader.TokenType)
            {
                case JsonToken.Null:
                    return null;
                case JsonToken.StartObject:
                {
                    var jsonObject   = JObject.Load(reader);
                    var date         = jsonObject["date"]?.ToString();
                    var timeZoneType = jsonObject["timezone_type"]?.ToObject<int>();
                    var timeZone     = jsonObject["timezone"]?.ToString();

                    if(date is null || timeZoneType is null || timeZone is null)
                    {
                        return null;
                    }

                    return new LastMessageTimeStamp(date, timeZoneType.Value, timeZone);
                }
                case JsonToken.Date:
                {
                    if(reader.Value is null)
                    {
                        return null;
                    }

                    return DateTime.TryParse(reader.Value.ToString(), out var timestamp) ? new LastMessageTimeStamp(timestamp.ToString("dd.MM.yyyy HH:mm:ss.ffffff"), 3, "UTC") : null;
                }
                default:
                    return null;
            }
        }

        public override bool CanRead => true;

        public override bool CanWrite => false;

        public override bool CanConvert(Type objectType)
        {
            return typeof(LastMessageTimeStamp).IsAssignableFrom(objectType);
        }
    }
}