using System;
using System.Linq;

using Engine.Serialization.DTOs;

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

namespace Engine.Serialization;

internal class StateEnableYamlConverter : IYamlTypeConverter
{
    public bool Accepts(Type type) => type == typeof(StateEnableDTO);

    public object ReadYaml(IParser parser, Type type)
    {
        if (parser.Current is not MappingStart)
            throw new InvalidOperationException("Expected MappingStart");

        parser.MoveNext();
        var stateEnable = new StateEnableDTO();
        while (parser.Current != null && parser.Current is not MappingEnd)
        {
            var propertyName = ((Scalar)parser.Current).Value;
            parser.MoveNext();
            switch (propertyName)
            {
                case nameof(StateEnableDTO.ClassType):
                    stateEnable.ClassType = ((Scalar)parser.Current).Value;
                    break;
                case nameof(StateEnableDTO.Enabled):
                    stateEnable.Enabled = bool.Parse(((Scalar)parser.Current).Value);
                    break;
            }
            parser.MoveNext();
        }
        return stateEnable;
    }

    public void WriteYaml(IEmitter emitter, object? value, Type type)
    {
        var stateEnable = (StateEnableDTO)(value ?? throw new Exception());

        emitter.Emit(new MappingStart());
        emitter.Emit(new Scalar(nameof(StateEnableDTO.ClassType)));
        emitter.Emit(new Scalar(stateEnable.ClassType));
        emitter.Emit(new Scalar(nameof(StateEnableDTO.Enabled)));
        emitter.Emit(new Scalar(stateEnable.Enabled.ToString()));
        emitter.Emit(new MappingEnd());
    }
}