using System;

using Newtonsoft.Json;

namespace Dalamud.Game
{
    /// <summary>
    /// Converts a <see cref="GameVersion"/> to and from a string (e.g. <c>"2010.01.01.1234.5678"</c>).
    /// </summary>
    public sealed class GameVersionConverter : JsonConverter
    {
        /// <summary>
        /// Writes the JSON representation of the object.
        /// </summary>
        /// <param name="writer">The <see cref="JsonWriter"/> to write to.</param>
        /// <param name="value">The value.</param>
        /// <param name="serializer">The calling serializer.</param>
        public override void WriteJson(JsonWriter writer, object? value, JsonSerializer serializer)
        {
            if (value == null)
            {
                writer.WriteNull();
            }
            else if (value is GameVersion)
            {
                writer.WriteValue(value.ToString());
            }
            else
            {
                throw new JsonSerializationException("Expected GameVersion object value");
            }
        }

        /// <summary>
        /// Reads the JSON representation of the object.
        /// </summary>
        /// <param name="reader">The <see cref="JsonReader"/> to read from.</param>
        /// <param name="objectType">Type of the object.</param>
        /// <param name="existingValue">The existing property value of the JSON that is being converted.</param>
        /// <param name="serializer">The calling serializer.</param>
        /// <returns>The object value.</returns>
        public override object? ReadJson(JsonReader reader, Type objectType, object? existingValue, JsonSerializer serializer)
        {
            if (reader.TokenType == JsonToken.Null)
            {
                return null;
            }
            else
            {
                if (reader.TokenType == JsonToken.String)
                {
                    try
                    {
                        return new GameVersion((string)reader.Value!);
                    }
                    catch (Exception ex)
                    {
                        throw new JsonSerializationException($"Error parsing GameVersion string: {reader.Value}", ex);
                    }
                }
                else
                {
                    throw new JsonSerializationException($"Unexpected token or value when parsing GameVersion. Token: {reader.TokenType}, Value: {reader.Value}");
                }
            }
        }

        /// <summary>
        /// Determines whether this instance can convert the specified object type.
        /// </summary>
        /// <param name="objectType">Type of the object.</param>
        /// <returns>
        /// <c>true</c> if this instance can convert the specified object type; otherwise, <c>false</c>.
        /// </returns>
        public override bool CanConvert(Type objectType)
        {
            return objectType == typeof(GameVersion);
        }
    }
}
