using System;

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

namespace Syntriax.Engine.Core.Serialization;

public class Line2DEquationSerializer : IEngineTypeYamlSerializer
{
    public bool Accepts(Type type) => type == typeof(Line2DEquation);

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

        if (parser.Consume<Scalar>().Value.CompareTo(nameof(Line2DEquation.Slope)) != 0)
            throw new ArgumentException($"{nameof(Line2DEquation)} mapping must start with {nameof(Line2DEquation.Slope)}");
        float slope = (float)rootDeserializer(typeof(float))!;

        if (parser.Consume<Scalar>().Value.CompareTo(nameof(Line2DEquation.OffsetY)) != 0)
            throw new ArgumentException($"{nameof(Line2DEquation)} mapping must end with {nameof(Line2DEquation.OffsetY)}");
        float offset = (float)rootDeserializer(typeof(float))!;

        parser.Consume<MappingEnd>();

        return new Line2DEquation(slope, offset);
    }

    public void WriteYaml(IEmitter emitter, object? value, Type type, ObjectSerializer serializer)
    {
        Line2DEquation line2DEquation = (Line2DEquation)value!;

        emitter.Emit(new MappingStart());
        emitter.Emit(new Scalar(nameof(Line2DEquation.Slope)));
        serializer(line2DEquation.Slope, typeof(float));
        emitter.Emit(new Scalar(nameof(Line2DEquation.OffsetY)));
        serializer(line2DEquation.OffsetY, typeof(float));
        emitter.Emit(new MappingEnd());
    }
}