using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Reflection;
using System.Runtime.InteropServices;
using UnityEngine;
using UnityEngine.Pool;

namespace BITKit.Entities.Variables
{
	public interface IVariable
	{
		string Variable { get; set; }
		string[] Variables { get; }
		event Action<string,string> OnVariableChanged;
		event Func<string,bool> TryChangeVariable;
		event Func<string> CollectVariables;
		
	}
    [Serializable]
	public sealed class IVariableFromDI : InjectFromDI<IVariable>,IVariable
	{
		private IVariable _variableImplementation => Value;
		public string Variable
		{
			get => _variableImplementation.Variable;
			set => _variableImplementation.Variable = value;
		}

		public string[] Variables => _variableImplementation.Variables;

		public event Action<string, string> OnVariableChanged
		{
			add => _variableImplementation.OnVariableChanged += value;
			remove => _variableImplementation.OnVariableChanged -= value;
		}

		public event Func<string, bool> TryChangeVariable
		{
			add => _variableImplementation.TryChangeVariable += value;
			remove => _variableImplementation.TryChangeVariable -= value;
		}

		public event Func<string> CollectVariables
		{
			add => _variableImplementation.CollectVariables += value;
			remove => _variableImplementation.CollectVariables -= value;
		}
	}

	[CustomType(typeof(IVariable),true)]
	public sealed class EntityVariable:MonoBehaviour,IVariable
	{
		public string Variable
		{
			get => _variable;
			set
			{
				if (TryChangeVariable is null || TryChangeVariable.CastAsFunc().All(Yes))
				{
					OnVariableChanged?.Invoke(_variable, _variable = value);
				}

				return;

				bool Yes(Func<string, bool> arg)
				{
					return arg.Invoke(value);
				}
			}
		}

		public string[] Variables {
			get
			{
				if (CollectVariables is null)
				{
					return Array.Empty<string>();
				}
				var listPool=ListPool<string>.Get();
				foreach (var x in CollectVariables.CastAsFunc())
				{
					listPool.Add(x.Invoke());
				}		
				var result = listPool.ToArray();
				ListPool<string>.Release(listPool);
				return result;
			}
		}
		public event Action<string,string> OnVariableChanged;
		public event Func<string,bool> TryChangeVariable;
		public event Func<string> CollectVariables;

		private string _variable="Default";

		private void Awake()
		{
			if (GetType().GetCustomAttribute<CustomTypeAttribute>() is { AsGlobal: true })
			{
				DI.Register<IVariable>(this);
			}
		}
	}
}