using System;
using System.Collections.Generic;

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

namespace Syntriax.Engine.Core.Serialization;

public class Shape2DSerializer : IEngineTypeYamlSerializer
{
    public bool Accepts(Type type) => type == typeof(Shape2D);

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

        if (parser.Consume<Scalar>().Value.CompareTo(nameof(Shape2D.Vertices)) != 0)
            throw new ArgumentException($"{nameof(Shape2D)} mapping have a {nameof(Shape2D.Vertices)}");

        parser.Consume<SequenceStart>();

        List<Vector2D> vertices = [];

        while (!parser.TryConsume<SequenceEnd>(out _))
        {
            Vector2D vertex = (Vector2D)rootDeserializer(typeof(Vector2D))!;
            vertices.Add(vertex);
        }

        parser.Consume<MappingEnd>();

        return new Shape2D(vertices);
    }

    public void WriteYaml(IEmitter emitter, object? value, Type type, ObjectSerializer serializer)
    {
        Shape2D shape2D = (Shape2D)value!;

        emitter.Emit(new MappingStart());
        emitter.Emit(new Scalar(nameof(Shape2D.Vertices)));
        emitter.Emit(new SequenceStart(anchor: null, tag: null, isImplicit: false, style: SequenceStyle.Block));
        foreach (Vector2D vertex in shape2D.Vertices)
            serializer(vertex, typeof(Vector2D));
        emitter.Emit(new SequenceEnd());
        emitter.Emit(new MappingEnd());
    }
}