using System;
using System.Linq;
using System.Linq.Expressions;
using HarmonyLib;
using Svelto.ECS;

namespace TechbloxModdingAPI.Common.Utils
{
    public static class EcsUtils
    {
        public static Type[] GetValidEntityComponents(Type entityDescriptorType)
        {
            // TODO: Cache
            var templateType = typeof(EntityDescriptorTemplate<>).MakeGenericType(entityDescriptorType);
            var templateDescriptor = AccessTools.Property(templateType, "descriptor");
            var getDescriptorExpr = Expression.MakeMemberAccess(null, templateDescriptor ?? throw new InvalidOperationException());
            var getTemplateDescriptorExpr = Expression.Lambda<Func<IEntityDescriptor>>(getDescriptorExpr);
            var getTemplateDescriptor = getTemplateDescriptorExpr.Compile();
            var builders = getTemplateDescriptor().componentsToBuild;
            return builders.Select(builder => builder.GetEntityComponentType()).ToArray();
        }
    }
}