using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using UnityEngine;
using UnityEngine.UIElements;

namespace BITKit.UX
{
	[AttributeUsage(AttributeTargets.Field|AttributeTargets.Property)]
	public class UXBindPathAttribute : Attribute
	{
		public string Path;
		public bool CanBeNull;
		public UXBindPathAttribute(){}
		public UXBindPathAttribute(string path)
		{
			Path = path;
		}
		public UXBindPathAttribute(string path,bool canBeNull)
		{
			Path = path;
			CanBeNull = canBeNull;
		}
	}
	public  class UXUtils
	{
		public static void Inject(object self)
		{
			UIDocument document;
			
			var field = self.GetType().GetField("document",
				BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);


			switch (field)
			{
				case null when self is MonoBehaviour monoBehaviour && monoBehaviour.TryGetComponent<UIDocument>(out document):
					break;
				case not null when field.GetValue(self) is UIDocument _document:
					document = _document;
					break;
				default:
					BIT4Log.Warning<UXUtils>($"document 未赋值或未找到");
					return;
			}
			
			foreach (var fieldInfo in self.GetType()
				         .GetFields(BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic)
				         .Where(x=>x.GetCustomAttribute<UXBindPathAttribute>() is not null)
			        )
			{
				var bindPathAtt = fieldInfo.GetCustomAttribute<UXBindPathAttribute>();
				VisualElement ve = document.rootVisualElement;
				foreach (var path in bindPathAtt.Path.Split("."))
				{
					ve = ve.Q(path);
				}
				//ve = document.rootVisualElement.Q(bindPathAtt.Path);
				if(bindPathAtt.CanBeNull is false && ve is null)
					BIT4Log.LogException(new NullReferenceException($"未找到{bindPathAtt.Path}"));

				if (fieldInfo.FieldType == typeof(UXContainer))
				{
					fieldInfo.SetValue(self,  new UXContainer(ve));
				}
				else
				{
					fieldInfo.SetValue(self,  ve);
				}
			
			}
			
			
			// if (field.GetValue(self) is not UIDocument _document)
			// {
			// 	if (self is MonoBehaviour monoBehaviour && (document = monoBehaviour.GetComponentInParent<UIDocument>()))
			// 	{
			// 		field.SetValue(self,document);
			// 	}
			// 	else
			// 	{
			// 		BIT4Log.Warning<UXUtils>($"document 未赋值");
			// 		return;
			// 	}
			// }
		
		}
	}
}