#pragma once
#include <memory>
#include <unordered_map>
#include <vector>
#include <functional>
#include <iostream>
#include <typeindex>
#include <type_traits>
#include "Event.h"
#include "EventHandler.h"
//#include "keyCodes.h"

class EventManager {
public:
	EventManager(const EventManager &) = delete;
	const EventManager & operator=(const EventManager &) = delete;
	static EventManager & get_instance() {
		static EventManager instance;
		return instance;
	}
	template <typename EventType>
	void subscribe(EventHandler<EventType> && callback, int channel = 0);
	void unsubscribe(std::type_index eventType, const std::string & handlerName,int channel);
	template <typename EventType>
	void trigger_event(const EventType & event, int channel);
	void queue_event(std::unique_ptr<Event> && event, int channel);
	void dispatch_events();

private:
	EventManager() = default;
	std::vector<std::pair<std::unique_ptr<Event>, int>> events_queue;
	std::unordered_map<std::type_index, std::vector<std::unique_ptr<IEventHandlerWrapper>>> subscribers;
	std::unordered_map<std::type_index, std::unordered_map<int, std::vector<std::unique_ptr<IEventHandlerWrapper>>>> subscribers_by_event_id;
};

template <typename EventType>
void EventManager::subscribe(EventHandler<EventType> && callback, int channel){
    std::type_index event_type = typeid(EventType);
    auto handler = std::make_unique<EventHandlerWrapper<EventType>>(callback);
    
    if (channel) {
        auto & handlers_map = subscribers_by_event_id[event_type];
        auto handlers = handlers_map.find(channel);
        if (handlers != handlers_map.end()) {
            handlers->second.emplace_back(std::move(handler));
        } else {
            handlers_map[channel].emplace_back(std::move(handler));
        }
    } else {
        subscribers[event_type].emplace_back(std::move(handler));
    }
}

template <typename EventType>
void EventManager::trigger_event(const EventType & event, int eventId) {
    std::type_index event_type = std::type_index(typeid(EventType));
    
    if (eventId > 0) {
        auto handlers_it = subscribers_by_event_id[event_type].find(eventId);
        if (handlers_it != subscribers_by_event_id[event_type].end()) {
            auto & callbacks = handlers_it->second;
            for (auto it = callbacks.begin(); it != callbacks.end();) {
                if ((*it)->exec(event)) {
                    it = callbacks.erase(it);
                } else {
                    ++it;
                }
            }
        }
    } else {
        auto & handlers = subscribers[event_type];
        for (auto & handler : handlers) {
            handler->exec(event);
        }
    }
}