using System;
using System.Collections.Generic;
using LanLib.Singleton;
using UnityEngine;

namespace LanLib.EventManager
{
    public sealed class EventManager : Singleton<EventManager>, IEventManager
    {
        private readonly Dictionary<Type, Delegate> _eventDictionary = new();
        public void Subscribe<T>(Action<T> listener) where T : struct
        {
            var eventId = typeof(T);
            if (listener is null)
            {
#if UNITY_EDITOR || DEVELOPMENT_BUILD
                Debug.LogError(ErrorMessages.NullListenerSubscribed(eventId));
                return;
#endif
            }
            if (_eventDictionary.ContainsKey(eventId))
            {
                _eventDictionary[eventId] = Delegate.Combine(_eventDictionary[eventId], listener);
                return;
            }
            _eventDictionary[eventId] = listener;
        }

        public void Unsubscribe<T>(Action<T> listener) where T : struct
        {
            var eventId = typeof(T);
            if (!_eventDictionary.ContainsKey(eventId)) return;
            _eventDictionary[eventId] = Delegate.Remove(_eventDictionary[eventId], listener);

            if (_eventDictionary[eventId] is null) _eventDictionary.Remove(eventId);
        }

        public void TriggerEvent<T>(T eventInstance) where T : struct
        {
            var eventId = typeof(T);
            if (!_eventDictionary.ContainsKey(eventId)) return;

            foreach (var listener in _eventDictionary[eventId].GetInvocationList())
            {
                try
                {
                    ((Action<T>)listener)?.Invoke(eventInstance);
                }
                catch (Exception exception)
                {
#if UNITY_EDITOR || DEVELOPMENT_BUILD
                    Debug.LogError(ErrorMessages.EventListenerTriggerException(eventId, exception));
#endif
                }
            }
        }

        public void ClearEvent<T>() where T : struct
        {
            var eventId = typeof(T);
            _eventDictionary.Remove(eventId);
        }

        public void ClearAllEvents() => _eventDictionary.Clear();
    }
}