using YamlDotNet.Core;
using YamlDotNet.Core.Events;
using YamlDotNet.Serialization;

namespace Syntriax.Engine.Serialization;

public class EntityReferenceConverter : IEngineTypeYamlConverter
{
    public bool Accepts(Type type) => type == typeof(EntityReference);

    public object? ReadYaml(IParser parser, Type type, ObjectDeserializer rootDeserializer)
    {
        parser.Consume<MappingStart>();

        if (parser.Consume<Scalar>().Value.CompareTo(nameof(EntityReference.Id)) != 0)
            throw new ArgumentException($"{nameof(EntityReference)} mapping must start with {nameof(EntityReference.Id)}");
        string id = parser.Consume<Scalar>().Value;

        TypeContainer typeContainer = (TypeContainer)rootDeserializer(typeof(TypeContainer))!;

        parser.Consume<MappingEnd>();

        return new EntityReference() { Id = id, TypeContainer = typeContainer };
    }

    public void WriteYaml(IEmitter emitter, object? value, Type type, ObjectSerializer serializer)
    {
        EntityReference? entityReference = (EntityReference)value!;

        emitter.Emit(new MappingStart());
        emitter.Emit(new Scalar(nameof(EntityReference.Id)));
        emitter.Emit(new Scalar(entityReference.Id));
        serializer(entityReference.TypeContainer, typeof(TypeContainer));
        emitter.Emit(new MappingEnd());
    }
}