using System;
using System.Collections.Concurrent;
using System.Reflection;
using System.Threading.Tasks;

namespace BITKit
{
    public abstract class InjectFromDI<T>
    {
        public T Value
        {
            get
            {
                return _value ??= DI.Get<T>();
            }
        }
        private T _value;
    }
    public sealed class DI
    {
        static readonly ConcurrentDictionary<Type, object> dictionary = new();
        [ExcuteOnStop]
        public static void Clear()
        {
            //dictionary.Clear();
        }
   
        public static void Register<Interface, Class>() where Class : new()
        {
            var type = typeof(Interface);

            lock (dictionary)
            {
                if (dictionary.ContainsKey(typeof(Interface)))
                {
                    BIT4Log.Log<DI>($"正在替换{type.Name}为{typeof(Class)}");
                }
            }

            lock (dictionary)
            {
                dictionary.GetOrAdd(typeof(Interface), new Class());
            }
        }
        public static void Register<Interface>(Interface c)
        {
            lock (dictionary)
            {
                dictionary.AddOrUpdate(typeof(Interface), c, (x, y) => c);
            }
        }
        public static void Register(Type t, Type c)
        {
            lock (dictionary)
                dictionary.AddOrUpdate(t, c, (x, y) => Activator.CreateInstance(c));
        }
        public static void Register(Type t, object c)
        {
            lock (dictionary)
                dictionary.AddOrUpdate(t, c, (x, y) => c);
        }
        public static T GetOrCreate<T>() where T : new()
        {
            lock (dictionary)
            {
                var di = dictionary.GetOrAdd(typeof(T), new T());
                if (di is T value)
                {
                    return value;
                }
            }
            throw new Exception();
        }
        public static T GetOrAdd<T>(Func<T> craftFactory)
        {
            lock (dictionary)
            {
                var di = dictionary.GetOrAdd(typeof(T), craftFactory.Invoke());
                if (di is T value)
                {
                    return value;
                }
            }
            throw new Exception();
        }
        public static T Get<T>()
        {
            lock (dictionary)
            {
                if (dictionary.TryGetValue(typeof(T), out var obj))
                {
                    if (obj is T i)
                    {
                        return i;
                    }
                }
                throw new NullReferenceException($"没有找到{typeof(T).Name}");
            }
        }
        public static bool TryGet<T>(out T value)
        {
            lock (dictionary)
            {
                if (dictionary.TryGetValue(typeof(T), out var obj))
                {
                    if (obj is T i)
                    {
                        value = i;
                        return true;
                    }
                }
            }
            value = default;
            return false;
        }
        public static async Task<Interface> GetAsync<Interface>()
        {
                await TaskHelper.WaitUntil(() => dictionary.ContainsKey(typeof(Interface)) && dictionary[typeof(Interface) ]is not null);

            return Get<Interface>();
        }
        /// <summary>
        /// 自动依赖注入,将所有带有<see cref="InjectAttribute"/>的字段注入
        /// </summary>
        /// <param name="obj"></param>
        public static void Inject(object obj)
        {
            foreach (var propertyInfo in obj.GetType().GetProperties(ReflectionHelper.Flags))
            {
                try
                {
                    if (propertyInfo.GetCustomAttribute<ObsoleteAttribute>() is null &&
                        propertyInfo.GetCustomAttribute<InjectAttribute>() is not null)
                    {
                        lock (dictionary)
                        {
                            if(dictionary!.TryGetValue(propertyInfo.PropertyType,out var value))
                            {
                                BIT4Log.Log<DI>($"已为{obj.GetType().Name}.{propertyInfo.Name}注入{value.GetType().Name}");
                                propertyInfo.SetValue(obj,value);
                            }
                        }
                    }
                }
                catch (Exception e)
                {
                    BIT4Log.LogException(e);
                }
              
            }
            foreach (var field in obj.GetType().GetFields(ReflectionHelper.Flags))
            {
                try
                {
                    if (field.GetCustomAttribute<ObsoleteAttribute>() is null &&
                        field.GetCustomAttribute<InjectAttribute>() is not null)
                    {
                        lock (dictionary)
                        {
                            if(dictionary!.TryGetValue(field.FieldType,out var value))
                            {
                                BIT4Log.Log<DI>($"已为{obj.GetType().Name}.{field.Name}注入{value.GetType().Name}");
                                field.SetValue(obj,value);
                            }
                        }
                    }
                }
                catch (Exception e)
                {
                    BIT4Log.LogException(e);
                }
              
            }
        }
    }
}