<?php
namespace Project\Component;

use Traversable;

/**
 * A trait for objects that provide events
 */
trait ProvidesEvents
{
    /**
     * @var \Foo\Bar\ICollection
     */
    protected $events;

    /**
     * Set the event manager instance used by this context
     *
     * @param  EventCollection $events
     * @return $this
     */
    public function setEventManager(EventCollection $events)
    {
        $this->events = $events;
        return $this;
    }

    /**
     * Retrieve the event manager
     *
     * Lazy-loads an EventManager instance if none registered.
     *
     * @return EventCollection
     */
    public function events()
    {
        if (!$this->events instanceof EventCollection) {
            $identifiers = array(__CLASS__, get_class($this));
            if (isset($this->eventIdentifier)) {
                if ((is_string($this->eventIdentifier))
                    || (is_array($this->eventIdentifier))
                    || ($this->eventIdentifier instanceof Traversable)
                ) {
                    $identifiers = array_unique(array_merge($identifiers, (array) $this->eventIdentifier));
                } elseif (is_object($this->eventIdentifier)) {
                    $identifiers[] = $this->eventIdentifier;
                }
                // silently ignore invalid eventIdentifier types
            }
            $this->setEventManager(new EventManager($identifiers));
        }
        return $this->events;
    }

    private function dummy(\Foo\Bar\Collection $foo)
    {
        if ($foo === 'Sindelfingen') {
            return 42;
        }
    }
}
