named-binary-tag/Nbt/Serialization/JsonNbt.cs

using System.Text;
using System.Text.Json;
using Nbt.Tag;

namespace Nbt.Serialization;

public static class JsonNbt
{
    private static readonly JsonEncodedText TypeProperty = JsonEncodedText.Encode("type");
    private static readonly JsonEncodedText ValueProperty = JsonEncodedText.Encode("value");

    #region Serialize lossless

    public static string Serialize(INbtTag tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtList tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtCompound tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtArray tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtArray<sbyte> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtArray<int> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtArray<long> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue<sbyte> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue<short> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue<int> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue<long> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue<float> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue<double> tag) => Serialize(serializer => serializer.Serialize(tag));
    public static string Serialize(INbtValue<string> tag) => Serialize(serializer => serializer.Serialize(tag));

    public static void Serialize(TextWriter writer, INbtTag tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtList tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtCompound tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtArray tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtArray<sbyte> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtArray<int> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtArray<long> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue<sbyte> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue<short> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue<int> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue<long> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue<float> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue<double> tag) => Serialize(writer, serializer => serializer.Serialize(tag));
    public static void Serialize(TextWriter writer, INbtValue<string> tag) => Serialize(writer, serializer => serializer.Serialize(tag));

    public static void Serialize(Stream stream, INbtTag tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtList tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtCompound tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtArray tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtArray<sbyte> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtArray<int> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtArray<long> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue<sbyte> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue<short> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue<int> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue<long> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue<float> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue<double> tag) => Serialize(stream, serializer => serializer.Serialize(tag));
    public static void Serialize(Stream stream, INbtValue<string> tag) => Serialize(stream, serializer => serializer.Serialize(tag));

    private static string Serialize(Action<Serializer> serialize)
    {
        using var writer = new StringWriter();
        Serialize(writer, serialize);
        return writer.ToString();
    }

    private static void Serialize(TextWriter writer, Action<Serializer> serialize)
    {
        using var stream = new MemoryStream();
        Serialize(stream, serialize);
        stream.Position = 0L;

        using var reader = new StreamReader(stream, encoding: Encoding.UTF8, leaveOpen: true);

        while (true)
        {
            var i = reader.Read();

            if (i < 0)
            {
                break;
            }

            writer.Write((char)i);
        }
    }

    private static void Serialize(Stream stream, Action<Serializer> serialize)
    {
        using var serializer = new Serializer(stream);
        serialize(serializer);
    }

    private sealed class Serializer(Stream stream) : IDisposable
    {
        private readonly Utf8JsonWriter writer = new(stream, new() { Indented = true, SkipValidation = true });

        public void Serialize(INbtTag tag)
        {
            switch (tag)
            {
                case INbtArray arrayTag:
                    Serialize(arrayTag);
                    break;

                case INbtValue valueTag:
                    Serialize(valueTag);
                    break;

                case INbtList listTag:
                    Serialize(listTag);
                    break;

                case INbtCompound compoundTag:
                    Serialize(compoundTag);
                    break;
            }
        }

        public void Serialize(INbtList tag)
        {
            using (new NbtObjectMeta(writer, tag.Type))
            {
                writer.WriteStartArray();

                foreach (var entry in tag)
                {
                    Serialize(entry);
                }

                writer.WriteEndArray();
            }
        }

        public void Serialize(INbtCompound tag)
        {
            using (new NbtObjectMeta(writer, tag.Type))
            {
                writer.WriteStartObject();

                foreach (var entry in tag as IEnumerable<NamedTag>)
                {
                    writer.WritePropertyName(entry.Name);
                    Serialize(entry.Tag);
                }

                writer.WriteEndObject();
            }
        }

        public void Serialize(INbtArray tag)
        {
            switch (tag)
            {
                case INbtArray<sbyte> byteArrayTag:
                    Serialize(byteArrayTag);
                    break;

                case INbtArray<int> intArrayTag:
                    Serialize(intArrayTag);
                    break;

                case INbtArray<long> longArrayTag:
                    Serialize(longArrayTag);
                    break;
            }
        }

        public void Serialize(INbtValue valueTag)
        {
            switch (valueTag)
            {
                case INbtValue<sbyte> tag:
                    Serialize(tag);
                    break;

                case INbtValue<short> tag:
                    Serialize(tag);
                    break;

                case INbtValue<int> tag:
                    Serialize(tag);
                    break;

                case INbtValue<long> tag:
                    Serialize(tag);
                    break;

                case INbtValue<float> tag:
                    Serialize(tag);
                    break;

                case INbtValue<double> tag:
                    Serialize(tag);
                    break;

                case INbtValue<string> tag:
                    Serialize(tag);
                    break;
            }
        }

        public void Serialize(INbtArray<sbyte> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtArray<int> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtArray<long> tag) => Serialize(tag, Serialize);

        public void Serialize(INbtValue<sbyte> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtValue<short> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtValue<int> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtValue<long> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtValue<float> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtValue<double> tag) => Serialize(tag, Serialize);
        public void Serialize(INbtValue<string> tag) => Serialize(tag, Serialize);

        private void Serialize<T>(INbtArray<T> tag, Action<T> writeValue) where T : notnull
        {
            using (new NbtObjectMeta(writer, tag.Type))
            {
                writer.WriteStartArray();

                foreach (var e in tag)
                {
                    writeValue(e);
                }

                writer.WriteEndArray();
            }
        }

        private void Serialize<T>(INbtValue<T> tag, Action<T> writeValue) where T : notnull
        {
            using (new NbtObjectMeta(writer, tag.Type))
            {
                writeValue(tag.Value);
            }
        }

        private void Serialize(sbyte value) => writer.WriteNumberValue(value);
        private void Serialize(short value) => writer.WriteNumberValue(value);
        private void Serialize(int value) => writer.WriteNumberValue(value);
        private void Serialize(long value) => writer.WriteNumberValue(value);
        private void Serialize(float value) => writer.WriteNumberValue(value);
        private void Serialize(double value) => writer.WriteNumberValue(value);
        private void Serialize(string value) => writer.WriteStringValue(value);

        public void Dispose()
        {
            writer.Dispose();

            GC.SuppressFinalize(this);
        }

        private readonly struct NbtObjectMeta : IDisposable
        {
            private readonly Utf8JsonWriter writer;

            public NbtObjectMeta(Utf8JsonWriter writer, NbtTagType tagType)
            {
                this.writer = writer;

                writer.WriteStartObject();
                writer.WriteNumber(TypeProperty, (int)tagType);
                writer.WritePropertyName(ValueProperty);
            }

            public void Dispose()
            {
                writer.WriteEndObject();
            }
        }
    }

    #endregion

    #region Serialize lossy

    public static string ToJson(INbtTag tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtList tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtCompound tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtArray tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtArray<sbyte> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtArray<int> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtArray<long> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue<sbyte> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue<short> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue<int> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue<long> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue<float> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue<double> tag) => ToJson(serializer => serializer.ToJson(tag));
    public static string ToJson(INbtValue<string> tag) => ToJson(serializer => serializer.ToJson(tag));

    public static void ToJson(TextWriter writer, INbtTag tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtList tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtCompound tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtArray tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtArray<sbyte> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtArray<int> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtArray<long> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue<sbyte> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue<short> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue<int> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue<long> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue<float> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue<double> tag) => ToJson(writer, serializer => serializer.ToJson(tag));
    public static void ToJson(TextWriter writer, INbtValue<string> tag) => ToJson(writer, serializer => serializer.ToJson(tag));

    public static void ToJson(Stream stream, INbtTag tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtList tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtCompound tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtArray tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtArray<sbyte> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtArray<int> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtArray<long> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue<sbyte> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue<short> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue<int> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue<long> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue<float> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue<double> tag) => ToJson(stream, serializer => serializer.ToJson(tag));
    public static void ToJson(Stream stream, INbtValue<string> tag) => ToJson(stream, serializer => serializer.ToJson(tag));

    private static string ToJson(Action<LossySerializer> serialize)
    {
        using var writer = new StringWriter();
        ToJson(writer, serialize);
        return writer.ToString();
    }

    private static void ToJson(TextWriter writer, Action<LossySerializer> serialize)
    {
        using var stream = new MemoryStream();
        ToJson(stream, serialize);
        stream.Position = 0L;

        using var reader = new StreamReader(stream, encoding: Encoding.UTF8, leaveOpen: true);

        while (true)
        {
            var i = reader.Read();

            if (i < 0)
            {
                break;
            }

            writer.Write((char)i);
        }
    }

    private static void ToJson(Stream stream, Action<LossySerializer> serialize)
    {
        using var serializer = new LossySerializer(stream);
        serialize(serializer);
    }

    private sealed class LossySerializer(Stream stream) : IDisposable
    {
        private readonly Utf8JsonWriter writer = new(stream, new() { Indented = true, SkipValidation = true });

        public void ToJson(INbtTag tag)
        {
            switch (tag)
            {
                case INbtArray arrayTag:
                    ToJson(arrayTag);
                    break;

                case INbtValue valueTag:
                    ToJson(valueTag);
                    break;

                case INbtList listTag:
                    ToJson(listTag);
                    break;

                case INbtCompound compoundTag:
                    ToJson(compoundTag);
                    break;
            }
        }

        public void ToJson(INbtList tag)
        {
            writer.WriteStartArray();

            foreach (var entry in tag)
            {
                ToJson(entry);
            }

            writer.WriteEndArray();
        }

        public void ToJson(INbtCompound tag)
        {
            writer.WriteStartObject();

            foreach (var entry in tag as IEnumerable<NamedTag>)
            {
                writer.WritePropertyName(entry.Name);
                ToJson(entry.Tag);
            }

            writer.WriteEndObject();
        }

        public void ToJson(INbtArray tag)
        {
            switch (tag)
            {
                case INbtArray<sbyte> byteArrayTag:
                    ToJson(byteArrayTag);
                    break;

                case INbtArray<int> intArrayTag:
                    ToJson(intArrayTag);
                    break;

                case INbtArray<long> longArrayTag:
                    ToJson(longArrayTag);
                    break;
            }
        }

        public void ToJson(INbtValue valueTag)
        {
            switch (valueTag)
            {
                case INbtValue<sbyte> tag:
                    ToJson(tag);
                    break;

                case INbtValue<short> tag:
                    ToJson(tag);
                    break;

                case INbtValue<int> tag:
                    ToJson(tag);
                    break;

                case INbtValue<long> tag:
                    ToJson(tag);
                    break;

                case INbtValue<float> tag:
                    ToJson(tag);
                    break;

                case INbtValue<double> tag:
                    ToJson(tag);
                    break;

                case INbtValue<string> tag:
                    ToJson(tag);
                    break;
            }
        }

        public void ToJson(INbtArray<sbyte> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtArray<int> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtArray<long> tag) => ToJson(tag, ToJson);

        public void ToJson(INbtValue<sbyte> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtValue<short> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtValue<int> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtValue<long> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtValue<float> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtValue<double> tag) => ToJson(tag, ToJson);
        public void ToJson(INbtValue<string> tag) => ToJson(tag, ToJson);

        private void ToJson<T>(INbtArray<T> tag, Action<T> writeValue) where T : notnull
        {
            writer.WriteStartArray();

            foreach (var e in tag)
            {
                writeValue(e);
            }

            writer.WriteEndArray();
        }

        private static void ToJson<T>(INbtValue<T> tag, Action<T> writeValue) where T : notnull => writeValue(tag.Value);

        private void ToJson(sbyte value) => writer.WriteNumberValue(value);
        private void ToJson(short value) => writer.WriteNumberValue(value);
        private void ToJson(int value) => writer.WriteNumberValue(value);
        private void ToJson(long value) => writer.WriteNumberValue(value);
        private void ToJson(float value) => writer.WriteNumberValue(value);
        private void ToJson(double value) => writer.WriteNumberValue(value);
        private void ToJson(string value) => writer.WriteStringValue(value);

        public void Dispose()
        {
            writer.Dispose();

            GC.SuppressFinalize(this);
        }
    }

    #endregion

    #region Deserialize

    public static INbtTag Deserialize(string s)
    {
        using var reader = new StringReader(s);
        return Deserialize(reader);
    }

    public static INbtTag Deserialize(Stream stream)
    {
        var doc = JsonDocument.Parse(stream);
        return Deserialize(doc.RootElement);
    }

    public static INbtTag Deserialize(TextReader reader)
    {
        using var stream = new MemoryStream();

        using (var writer = new StreamWriter(stream, encoding: Encoding.UTF8, leaveOpen: true))
        {
            while (true)
            {
                var i = reader.Read();

                if (i < 0)
                {
                    break;
                }

                writer.Write((char)i);
            }
        }

        stream.Position = 0L;

        return Deserialize(stream);
    }

    private static INbtTag Deserialize(JsonElement serialized)
    {
        var tagType = (NbtTagType)serialized.GetProperty(TypeProperty.Value).GetByte();
        var value = serialized.GetProperty(ValueProperty.Value);

        switch (tagType)
        {
            case NbtTagType.End:
                throw new NbtException($"Invalid tag type: {Enum.GetName(tagType)}");

            case NbtTagType.Byte:
                return new NbtByte(value.GetSByte());
            case NbtTagType.Short:
                return new NbtShort(value.GetInt16());
            case NbtTagType.Int:
                return new NbtInt(value.GetInt32());
            case NbtTagType.Long:
                return new NbtLong(value.GetInt64());
            case NbtTagType.Float:
                return new NbtFloat(value.GetSingle());
            case NbtTagType.Double:
                return new NbtDouble(value.GetDouble());
            case NbtTagType.String:
                return new NbtString(value.GetString() ?? throw new NbtException("Null string value"));

            case NbtTagType.ByteArray:
                {
                    var bytes = new sbyte[value.GetArrayLength()];
                    var i = 0;

                    foreach (var element in value.EnumerateArray())
                    {
                        bytes[i++] = element.GetSByte();
                    }

                    return new NbtByteArray(bytes);
                }

            case NbtTagType.IntArray:
                {
                    var ints = new int[value.GetArrayLength()];
                    var i = 0;

                    foreach (var element in value.EnumerateArray())
                    {
                        ints[i++] = element.GetInt32();
                    }

                    return new NbtIntArray(ints);
                }

            case NbtTagType.LongArray:
                {
                    var longs = new long[value.GetArrayLength()];
                    var i = 0;

                    foreach (var element in value.EnumerateArray())
                    {
                        longs[i++] = element.GetInt64();
                    }

                    return new NbtLongArray(longs);
                }

            case NbtTagType.List:
                {
                    var list = new NbtList();

                    foreach (var element in value.EnumerateArray())
                    {
                        list.Add(Deserialize(element));
                    }

                    return list;
                }

            case NbtTagType.Compound:
                {
                    var compound = new NbtCompound();

                    foreach (var property in value.EnumerateObject())
                    {
                        compound.Add(property.Name, Deserialize(property.Value));
                    }

                    return compound;
                }

            default:
                throw new UnknownTagTypeException(tagType);
        }
    }

    #endregion
}