using Serilog;
using System;
using System.Collections.Concurrent;
using Wood.EventBus.Events;
using Wood.Util;

namespace Wood.EventBus
{
    public class InMemoryEventBus : IEventBus
    {
        private readonly ConcurrentDictionary<string, List<object>> _handlersMap = new();

        public void Subscribe<T, TH>(TH handler) where T : IntegrationEvent where TH : IIntegrationEventHandler<T>
        {
            var eventName = typeof(T).Name;
            if (!_handlersMap.TryGetValue(eventName, out var handlers))
            {
                handlers = new List<object>();
                _handlersMap.TryAdd(eventName, handlers);
            }
            handlers.Add(handler);
        }

        public void Unsubscribe<T, TH>() where T : IntegrationEvent where TH : IIntegrationEventHandler<T>
        {
            var eventName = typeof(T).Name;
            if (_handlersMap.TryGetValue(eventName, out var handlers))
            {
                handlers.RemoveAll(h => h is TH);
            }
        }

        public async Task PublishAsync<T>(T @event) where T : IntegrationEvent
        {
            var eventName = typeof(T).Name;
            if (_handlersMap.TryGetValue(eventName, out var handlers))
            {
                foreach (var handler in handlers)
                {
                    var methodInfo = handler.GetType().GetMethods().FirstOrDefault(m => m.Name == "Handle" && m.GetParameters().Length == 1 && m.GetParameters()[0].ParameterType == typeof(T));
                    if (methodInfo != null)
                    {
                        await (Task)methodInfo.Invoke(handler, new object[] { @event })!;
                    }
                }
            }
        }

        public void Publish<T>(T @event) where T : IntegrationEvent
        {
            var eventName = typeof(T).Name;
            if (_handlersMap.TryGetValue(eventName, out var handlers))
            {
                foreach (var handler in handlers)
                {
                    var methodInfo = handler.GetType().GetMethods().FirstOrDefault(m => m.Name == "Handle" && m.GetParameters().Length == 1 && m.GetParameters()[0].ParameterType == typeof(T));
                    if (methodInfo != null)
                    {
                        methodInfo.Invoke(handler, new object[] { @event });
                    }
                }
            }
        }
    }
}