using System;
using System.Collections.Generic;

using UnityEngine.Events;

namespace PMaker.Messaging
{
    public static class DomainEvents<TMessage> where TMessage : class
    {
        public static event Action<TMessage> OnMessage;

        public static void Publish(TMessage message)
        {
            OnMessage(message);
        }

        public static void Subscribe(Action<TMessage> handler)
        {
            OnMessage += handler;
        }

        public static void Unsubscribe(Action<TMessage> handler)
        {
            OnMessage -= handler;
        }

        public static void Clear()
        {
            OnMessage = default;
        }
    }

    public static class DomainEvents<TRoute, TMessage> where TMessage : class where TRoute : class
    {
        public delegate void MessageDelegate(TMessage message);

        static readonly Dictionary<TRoute, MessageDelegate> _listeners = new Dictionary<TRoute, MessageDelegate>();

        public static void Publish(TRoute route, TMessage message)
        {
            if (_listeners.TryGetValue(route, out var handle) == true)
            {
                handle?.Invoke(message);
            }
        }

        public static void Subscribe(TRoute route, MessageDelegate handler)
        {
            if (!_listeners.ContainsKey(route))
            {
                _listeners.Add(route, default);
            }
            _listeners[route] += handler;
        }

        public static void Unsubscribe(TRoute route, MessageDelegate handler)
        {
            if (_listeners.ContainsKey(route))
            {
                _listeners[route] -= handler;
            }
        }

        public static void Unsubscribe(TRoute route)
        {
            if (_listeners.ContainsKey(route))
            {
                _listeners.Remove(route);
            }
        }

        public static void Clear()
        {
            _listeners.Clear();
        }
    }

    public static class DomainEvents
    {
        public static void Publish<TMessage>(TMessage message) where TMessage : class
        {
            DomainEvents<TMessage>.Publish(message);
        }

        public static void Publish<TRoute, TMessage>(TRoute route, TMessage message) where TMessage : class
          where TRoute : class
        {
            DomainEvents<TRoute, TMessage>.Publish(route, message);
        }
    }
    
    public static class DomainEventsUnityEventExtension
    {
        public static void Binding<TRoute, TMessage>(this UnityEvent unityEvent, TRoute route, TMessage message) where TRoute : class where TMessage : class
        {
            unityEvent.AddListener(() => { DomainEvents<TRoute, TMessage>.Publish(route, message); });
        }

        public static void Binding<TMessage>(this UnityEvent unityEvent, TMessage message) where TMessage : class
        {
            unityEvent.AddListener(() => { DomainEvents<TMessage>.Publish(message); });
        }
    }
}