package de.mrbesen.telegram.event;

import de.mrbesen.telegram.TelegramAPI;

import java.lang.reflect.Array;
import java.lang.reflect.Method;
import java.util.ArrayList;
import java.util.HashMap;

public class EventManager {

	private HashMap<Class<? extends Event>, ArrayList<EventListener>> listeners = new HashMap<>();

	public EventManager() {}

	public void registerEvent(Class<? extends Event> eventtype, EventListener listener) {
		if (listener == null) {
			throw new NullPointerException();
		}

		//get list
		ArrayList<EventListener> list = listeners.get(eventtype);
		if (list == null) {
			list = new ArrayList<EventListener>();
			listeners.put(eventtype, list);
		} else if(list.contains(listener)) {
			throw new IllegalArgumentException("listener allready registered");
		}

		list.add(listener);
	}

	public Event callEvent(Event e) {
		if(e == null)
			throw new NullPointerException("event is not allowed to be null!");
		ArrayList<EventListener> listner = listeners.get(e.getClass());
		for(EventListener listn : listner) {
			try {
				listn.handleEvent(e);
			} catch(Throwable t) {
				System.err.println("Error occurred on Handling Event: " + e.getClass().getSimpleName());
				t.printStackTrace();
			}
		}
		return e;
	}
}