using System;
using System.Buffers;
using System.Collections.Generic;
using AlicizaX.Runtime;
using Cysharp.Threading.Tasks;
using UnityEngine;
using UnityEngine.Pool;

namespace AlicizaX.UI.Runtime
{
    public abstract partial class UIBase
    {
        private readonly Dictionary<UIBase, UIMetadata> _children = new();

        private void UpdateChildren()
        {
            var values = _children.Values; // O(1) 操作
            foreach (var meta in values)
            {
                if (meta.View.State == UIState.Opened)
                {
                    meta.View.InternalUpdate();
                }
            }
        }

        private void DestroyAllChildren()
        {
            var temp = ArrayPool<UIMetadata>.Shared.Rent(_children.Count);
            try
            {
                int i = 0;
                foreach (var kvp in _children)
                {
                    temp[i++] = kvp.Value;
                }

                for (int j = 0; j < i; j++)
                {
                    temp[j].Dispose();
                }
            }
            finally
            {
                ArrayPool<UIMetadata>.Shared.Return(temp);
            }

            _children.Clear();
        }

        private void ChildVisible(bool value)
        {
            foreach (var meta in _children.Values)
            {
                var view = meta.View;
                if (view.State == UIState.Opened)
                {
                    view.Visible = value;
                }
            }
        }

        protected T CreateWidget<T>(Transform parent) where T : UIWidget
        {
            UIMetadata metadata = MetaTypeCache<T>.Metadata;
            metadata.CreateUI();
            UILoaderFactory.LoadUIResourcesSync(metadata, parent, this);
            ProcessWidget(metadata);
            return (T)metadata.View;
        }

        protected T CreateWidget<T>(UIHolderObjectBase holder) where T : UIWidget
        {
            UIMetadata metadata = MetaTypeCache<T>.Metadata;
            metadata.CreateUI();
            UIWidget widget = (UIWidget)metadata.View;
            widget.BindUIHolder(holder.gameObject, this);
            ProcessWidget(metadata);
            return (T)widget;
        }

        protected async UniTask<T> CreateWidgetAsync<T>(Transform parent) where T : UIBase
        {
            UIMetadata metadata = MetaTypeCache<T>.Metadata;
            metadata.CreateUI();
            await UILoaderFactory.LoadUIResourcesAsync(metadata, parent, this);
            ProcessWidget(metadata);
            return (T)metadata.View;
        }

        private void ProcessWidget(UIMetadata meta)
        {
            AddWidget(meta);
            meta.View.InternalInitlized();
            if (meta.View.Holder.Visible)
            {
                meta.View.InternalOpen();
            }
        }

        private void AddWidget(UIMetadata meta)
        {
            if (!_children.TryAdd(meta.View, meta))
            {
                meta.Dispose();
                Log.Warning("Already has widget:{0}", meta.View);
            }
        }

        public void RemoveWidget(UIBase widget)
        {
            if (_children.Remove(widget, out var meta))
            {
                meta.Dispose();
            }
        }
    }
}