using System;
using System.Collections.Concurrent;
using System.Collections.Generic;
using Cysharp.Threading.Tasks;

namespace BITKit
{
    public interface IValidHandle
    {
        bool Allow { get; }
        void AddElement(object obj);
        void RemoveElement(object obj);
        void AddDisableElements(object obj);
        void RemoveDisableElements(object obj);
        void SetElements(object obj, bool add = true);
        void SetDisableElements(object obj, bool add = true);
        void Invoke();
        void Invoke(bool value);
        void AddListener(Action<bool> action);
        void RemoveListener(Action<bool> action);
        void Clear();
    }
    
    [CustomType(typeof(IValidHandle))]
    public sealed class ValidHandle: IValidHandle,IDisposable
    {
        public class MyHandle:IDisposable
        {
            private readonly ValidHandle _validHandle;
            private readonly bool _isDisable;
            public MyHandle(ValidHandle validHandle,bool isDisable = false)
            {
                _validHandle = validHandle;

                _isDisable = isDisable;
                if (isDisable)
                {
                    _validHandle.AddDisableElements(this);
                }
                else
                {
                    _validHandle.AddElement(this);
                }
          
            }
            public void Dispose()
            {
                if (_isDisable)
                {
                    _validHandle.RemoveDisableElements(this);
                }
                else
                {
                    _validHandle.RemoveElement(this);
                }
            }
        }

        public MyHandle GetHandle() => new MyHandle(this);
        public MyHandle GetDisableHandle()=> new MyHandle(this,true);
        
        public override string ToString()
        {
            return $"Allow:{_enableHandle}\nElements:{string.Join("\n",_objs)}\nDisableElements:{string.Join("\n",_disableObjs)}";
        }

        public ValidHandle() {}
        public ValidHandle(Action<bool> boolDelegate)
        {
            AddListener(boolDelegate);
            _eventOnEnableChanged?.Invoke(_enableHandle);
        }
        public static implicit operator bool(ValidHandle validHandle)
        {
            return !validHandle._isDisposed && validHandle._enableHandle;
        }

        public bool Allow => this;
        
        private bool _enableHandle;
        /// <summary>
        /// ⚠️Dont operate this field directly
        /// </summary>
        private readonly HashSet<object> _objs = new();

        /// <summary>
        /// ⚠️Dont operate this field directly
        /// </summary>
        private readonly HashSet<object> _disableObjs = new();
        private bool _tempEnable;
        private Action<bool> _eventOnEnableChanged;
        private readonly ConcurrentQueue<UniTaskCompletionSource> _completionSources = new();
        private bool _isDisposed;
        
        public void AddElement(object obj)
        {
            _objs.Add(obj);
            CheckEnable();
        }

        private void CheckEnable()
        {
            _tempEnable = _objs.Count > 0 && _disableObjs.Count == 0;
            if (_tempEnable == _enableHandle) return;
            _enableHandle = _tempEnable;
            _eventOnEnableChanged?.Invoke(_enableHandle);
            if (_tempEnable) return;
            if (_completionSources.TryDequeue(out var cs))
            {
                cs.TrySetResult();
            }
        }
        public void RemoveElement(object obj)
        {
            if (_objs.Contains(obj))
            {
                _objs.Remove(obj);
            }

            CheckEnable();
        }
        public int Lenght => _objs.Count;
        public bool Contains(object obj) => _objs.Contains(obj);
        public void AddDisableElements(object obj)
        {
            _disableObjs.Add(obj);
            CheckEnable();
        }
        public void RemoveDisableElements(object obj)
        {
            if (_disableObjs.Contains(obj))
            {
                _disableObjs.Remove(obj);
            }
            else
            {
            }
            CheckEnable();
        }
        public void SetElements(object obj, bool add = true)
        {
            if (add)
            {
                AddElement(obj);
            }
            else
            {
                RemoveElement(obj);
            }
        }
        public void SetDisableElements(object obj, bool add = true)
        {
            if (add)
            {
                AddDisableElements(obj);
            }
            else
            {
                RemoveDisableElements(obj);
            }
        }
        public void Invoke()
        {
            var enable = _disableObjs.Count == 0 && _objs.Count > 0;
            _eventOnEnableChanged?.Invoke(enable);
        }
        public void Invoke(bool value)
        {
            _eventOnEnableChanged?.Invoke(value);
        }
        public void AddListener(Action<bool> action)
        {
            _eventOnEnableChanged+= action;
        }
        public void RemoveListener(Action<bool> action)
        {
            if(_eventOnEnableChanged is not null && action is not  null)
            {
                _eventOnEnableChanged -= action;
            }
        }
        public UniTask.Awaiter GetAwaiter()
        {
            if (Allow is false)
            {
                return UniTask.CompletedTask.GetAwaiter();
            }
            var cs = new UniTaskCompletionSource();
            _completionSources.Enqueue(cs);
            return cs.Task.GetAwaiter();
        }
        public void Clear()
        {
            _objs.Clear();
            _disableObjs.Clear();
            Invoke();
        }

        public void Dispose()
        {
            _isDisposed = true;
            _objs.Clear();
            _disableObjs.Clear();
            _eventOnEnableChanged = null;
        }
    }
    
}