<?php
/**
 * @package   AkeebaEngage
 * @copyright Copyright (c)2020-2022 Nicholas K. Dionysopoulos / Akeeba Ltd
 * @license   GNU General Public License version 3, or later
 */

defined('_JEXEC') or die;

use FOF40\Container\Container;
use Joomla\CMS\Factory;
use Joomla\CMS\Plugin\CMSPlugin;

/**
 * Workaround for paginated frontend comments display to guest users when caching is enabled.
 */
class plgSystemEngagecache extends CMSPlugin
{
	public function __construct(&$subject, $config = [])
	{
		if (!defined('FOF40_INCLUDED') && !@include_once(JPATH_LIBRARIES . '/fof40/include.php'))
		{
			$this->enabled = false;
		}

		parent::__construct($subject, $config);
	}

	/**
	 * Fixes the frontend display of comments for guests when caching is enabled.
	 *
	 * Joomla caches the entire article contents, including the plugin output, for guest users. The problem is that
	 * while this takes into account Joomla's pagination it does not take into account the comment pagination.
	 *
	 * Fortunately, BaseController::display does take into account a stdClass object named registeredurlparams if it's
	 * already set in the Joomla application object. This property does not exist in the base CMSApplication class and
	 * you'd be hard pressed to know it's a thing just by reading Joomla's developer documentation. Anyway, it is used
	 * if it's there so we prime it with the contents of our pagination parameters. This forces Joomla to take into
	 * account BOTH the active component's (e.g. com_content) caching parameters AND our comment pagination parameters.
	 *
	 * @return  void
	 *
	 * @see     BaseController::display()
	 */
	public function onAfterInitialise()
	{
		try
		{
			$app = Factory::getApplication();
		}
		catch (Exception $e)
		{
			return;
		}

		$masterContainer  = Container::getInstance('com_engage');
		$defaultListLimit = $masterContainer->params->get('default_limit', 20);
		$defaultListLimit = ($defaultListLimit == -1) ? 20 : $defaultListLimit;

		$limitStart = $app->input->getInt('akengage_limitstart', 0);
		$limit      = $app->input->getInt('akengage_limit', $defaultListLimit);

		if (!empty($app->registeredurlparams))
		{
			$registeredurlparams = $app->registeredurlparams;
		}
		else
		{
			$registeredurlparams = new stdClass;
		}

		if (!empty($limitStart))
		{
			$registeredurlparams->akengage_limitstart = $limitStart;
		}

		$registeredurlparams->akengage_limit = $limit;

		$app->registeredurlparams = $registeredurlparams;
	}
}