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

namespace DanieleMarotta.RiversongCodeShowcase
{
    public abstract class GameSystemGroup : IGameSystem, IInitializable, IUpdatable, IDisposable
    {
        private List<IInitializable> _initializables = new();

        private List<IUpdatable> _updatables = new();

        private List<IDisposable> _disposables = new();

        public virtual string Name => GetType().Name;

        public List<IGameSystem> Systems { get; } = new();

        public IUpdateFilter UpdateFilter { get; set; }

        public void Add(IGameSystem system)
        {
            Systems.Add(system);
            if (system is IInitializable initializable) _initializables.Add(initializable);
            if (system is IUpdatable updatable) _updatables.Add(updatable);
            if (system is IDisposable disposable) _disposables.Add(disposable);
        }

        public virtual async UniTask InitializeAsync()
        {
            SystemSorter.InitializableSorter.Sort(_initializables);
            SystemSorter.UpdatableSorter.Sort(_updatables);
            SystemSorter.DisposableSorter.Sort(_disposables);

            var batches = SystemSorter.InitializableSorter.CreateExecutionBatches(_initializables);
            foreach (var batch in batches)
            {
                var tasks = new UniTask[batch.Count];
                for (var i = 0; i < batch.Count; i++) tasks[i] = InitializeAndLogAsync(batch[i]);

                await UniTask.WhenAll(tasks);
            }
        }

        private static async UniTask InitializeAndLogAsync(IInitializable initializable)
        {
            var startTime = Time.unscaledTime;

            await initializable.InitializeAsync();

            LogInitializationTime(initializable, startTime);
        }

        private static void LogInitializationTime(IInitializable initializable, float startTime)
        {
            if (initializable is GameSystemGroup) return;

            var elapsed = Time.unscaledTime - startTime;

            var log = $"Initialized {((IGameSystem)initializable).Name} in {(int)(elapsed * 1000)} ms";
            if (elapsed > 0.3f) log = $"<color=yellow>{log}</color>";

            Debug.Log(log);
        }

        public virtual void Update()
        {
            foreach (var updatable in _updatables)
            {
                if (UpdateFilter != null && !UpdateFilter.CanUpdate(updatable)) continue;

                updatable.Update();
            }
        }

        public virtual void Dispose()
        {
            foreach (var disposable in _disposables) disposable.Dispose();
        }
    }
}