#include "EventBus.h"

#include "IEvent.h"

#include "EventSubscriber.h"

#include <algorithm>

namespace sh::core

{

EventBus::~EventBus()

{

for (auto& [hash, subscribers] : listeners)

{

for (auto& subscriber : subscribers)

{

subscriber->eventBus = nullptr;

}

}

}

SH_CORE_API void EventBus::Subscribe(ISubscriber& subscriber)

{

subscriber.eventBus = this;

const auto eventTypeHash = subscriber.GetEventTypeHash();

listeners[eventTypeHash].push_back(&subscriber);

}

SH_CORE_API void EventBus::Unsubscribe(ISubscriber& subscriber)

{

const auto eventTypeHash = subscriber.GetEventTypeHash();

auto it = listeners.find(eventTypeHash);

if (it == listeners.end())

return;

auto& subscribers = it->second;

auto removeIt = std::remove(subscribers.begin(), subscribers.end(), &subscriber);

if (removeIt == subscribers.end())

return;

subscriber.eventBus = nullptr;

subscribers.erase(removeIt, subscribers.end());

}

SH_CORE_API void EventBus::Publish(const IEvent& event)

{

const auto eventTypeHash = event.GetTypeHash();

auto it = listeners.find(eventTypeHash);

if (it == listeners.end())

return;

std::vector<ISubscriber*> subscribersCopy = it->second;

for (auto* subscriber : subscribersCopy)

{

if (subscriber->eventBus)

subscriber->Invoke(event);

}

}

}