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

namespace Framework.Core
{
    [AttributeUsage(AttributeTargets.Field, AllowMultiple = false)]
    public class FindComponentAttribute : Attribute
    {
        public readonly string goName;
        public readonly bool getChild;
        /// <summary>
        /// 查找游戏物体组件的特性
        /// </summary>
        /// <param name="goName">游戏物体名字</param>
        /// <param name="getChild">
        /// true => 查找对应名字对象的下一级子物体 通常名字为父物体名字 类型为子物体
        /// false => 查找对应名字的对象 通常会将类型和名字对应</param>
        public FindComponentAttribute(string goName, bool getChild = true)
        {
            this.goName = goName;
            this.getChild = getChild;
        }
    }
    
    public static class UnityTool
    {
        /// <summary>
        /// 查找所有带标记的组件
        /// 与FindComponent特性配合使用
        /// </summary>
        public static void FindComponents(this Component mono)
        {
            Dictionary<Type, Component[]> dic = null;
            var flags = BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance;
            foreach (var field in mono.GetType().GetFields(flags))
            {
                var attribute = field.GetCustomAttribute<FindComponentAttribute>();
                if (attribute == null) continue;
                dic ??= new Dictionary<Type, Component[]>();
                Type type = field.FieldType;
                if (!dic.TryGetValue(type, out var components))
                {
                    components = mono.GetComponentsInChildren(type, true);
                    if (components == null || components.Length == 0)
                    {
#if UNITY_EDITOR
                        Debug.Log($"无法找到{type}对象");
#endif
                        continue;
                    }
                    dic.Add(type, components);
                }
                if (attribute.getChild)
                {
                    foreach (var component in components)
                    {
                        if (component.transform.parent.name == attribute.goName)
                        {
                            field.SetValue(mono, component);
                            break;
                        }
                    }
                }
                else
                {
                    foreach (var component in components)
                    {
                        if (component.name != attribute.goName) continue;
                        field.SetValue(mono, component);
                        break;
                    }
                }
            }
        }
    }
}