using System.Text.Json;
using System.Text.Json.Serialization;

namespace OMS.NET.Common
{
    public class UserInfo
    {
        public string? Name { get; set; }
        public string? Email { get; set; }
        public string? Color { get; set; }
    }

    public class ActiveDataElement
    {
        public string EID { get; set; }
        public UserInfo? Pick { get; set; }
        public UserInfo? Select { get; set; }

        public ActiveDataElement(string id)
        {
            EID = "E" + id;
        }
    }

    public class ActiveDataElementConverter : JsonConverter<ActiveDataElement>
    {
        public override ActiveDataElement Read(ref Utf8JsonReader reader, Type typeToConvert, JsonSerializerOptions options)
        {
            if (reader.TokenType != JsonTokenType.StartObject)
            {
                throw new JsonException();
            }
            reader.Read();
            string? eid = (reader.GetString()?[1..]) ?? throw new JsonException(); // Removing 'E' prefix to get the ID
            var element = new ActiveDataElement(eid);
            while (reader.Read())
            {
                if (reader.TokenType == JsonTokenType.EndObject)
                {
                    break;
                }

                if (reader.TokenType == JsonTokenType.StartObject)
                {
                    continue;
                }

                if (reader.TokenType != JsonTokenType.PropertyName)
                {
                    throw new JsonException();
                }

                string? propertyName = reader.GetString();
                reader.Read();

                switch (propertyName)
                {
                    case "pick":
                        element.Pick = DeserializeUserInfo(ref reader);
                        break;
                    case "select":
                        element.Select = DeserializeUserInfo(ref reader);
                        break;
                    default:
                        reader.Skip(); // Skip unknown properties
                        break;
                }
            }
            //reader.CurrentDepth = 0;
            reader.Read();
            //还需要读取一次，因为之前有过一次读取，跳过了一个token，最后一个token也要读一次
            return element;
        }

        public override void Write(Utf8JsonWriter writer, ActiveDataElement value, JsonSerializerOptions options)
        {
            writer.WriteStartObject();
            writer.WritePropertyName(value.EID);
            writer.WriteStartObject();
            if (value.Pick != null) { WriteUserInfo(writer, "pick", value.Pick); }
            if (value.Select != null) { WriteUserInfo(writer, "select", value.Select); }
            writer.WriteEndObject();
            writer.WriteEndObject();
        }

        private static void WriteUserInfo(Utf8JsonWriter writer, string propertyName, UserInfo userInfo)
        {
            writer.WriteStartObject(propertyName);
            if (userInfo != null)
            {
                writer.WriteString("name", userInfo.Name);
                writer.WriteString("email", userInfo.Email);
                writer.WriteString("color", userInfo.Color);
            }
            writer.WriteEndObject();
        }

        private static UserInfo DeserializeUserInfo(ref Utf8JsonReader reader)
        {
            if (reader.TokenType != JsonTokenType.StartObject)
            {
                throw new JsonException();
            }

            string? name = null;
            string? email = null;
            string? color = null;

            while (reader.Read())
            {
                if (reader.TokenType == JsonTokenType.EndObject)
                {
                    break;
                }
                if (reader.TokenType != JsonTokenType.PropertyName)
                {
                    throw new JsonException();
                }
                string? propertyName = reader.GetString();
                reader.Read();
                switch (propertyName)
                {
                    case "name":
                        name = reader.GetString();
                        break;
                    case "email":
                        email = reader.GetString();
                        break;
                    case "color":
                        color = reader.GetString();
                        break;
                    default:
                        reader.Skip(); // Skip unknown properties
                        break;
                }
            }
            return new UserInfo { Name = name, Email = email, Color = color };
        }
    }
}