using System;
using System.Collections.Generic;
using Cysharp.Threading.Tasks;
using UnityEngine;

namespace DanieleMarotta.RiversongCodeShowcase
{
    [GameSystemGroup(typeof(DebugSystemGroup))]
    public class DrawGizmosSystem : GameSystem, IInitializable, IDisposable
    {
        [InjectService]
        private IEngine _engine;

        private DrawGizmosSceneProxy _sceneProxy;

        private List<IDrawGizmos> _callbacks = new();

        public DrawGizmosSystem(IServiceLocator serviceLocator) : base(serviceLocator)
        {
        }

        public UniTask InitializeAsync()
        {
#if DEBUG
            _sceneProxy = new GameObject(nameof(DrawGizmosSceneProxy)).AddComponent<DrawGizmosSceneProxy>();
            _sceneProxy.DrawGizmos += OnDrawGizmos;
#endif

            foreach (var system in _engine.Systems)
                if (system is IDrawGizmos callback)
                    _callbacks.Add(callback);

            return UniTask.CompletedTask;
        }

        public void Dispose()
        {
            _sceneProxy.DrawGizmos -= OnDrawGizmos;
        }

        private void OnDrawGizmos(bool selected)
        {
            foreach (var callback in _callbacks) callback.DrawGizmos(selected);
        }

        private class DrawGizmosSceneProxy : MonoBehaviour
        {
            public event Action<bool> DrawGizmos;

            private void OnDrawGizmos()
            {
                DrawGizmos?.Invoke(false);
            }

            private void OnDrawGizmosSelected()
            {
                DrawGizmos?.Invoke(true);
            }
        }
    }
}