<?php
/**
 * INCHOO's FREE EXTENSION DISCLAIMER
 *
 * Please do not edit or add to this file if you wish to upgrade Magento
 * or this extension to newer versions in the future.
 *
 * Inchoo developers (Inchooer's) give their best to conform to
 * "non-obtrusive, best Magento practices" style of coding.
 * However, Inchoo does not guarantee functional accuracy of specific
 * extension behavior. Additionally we take no responsibility for any
 * possible issue(s) resulting from extension usage.
 *
 * We reserve the full right not to provide any kind of support for our free extensions.
 *
 * You are encouraged to report a bug, if you spot any,
 * via sending an email to bugreport@inchoo.net. However we do not guaranty
 * fix will be released in any reasonable time, if ever,
 * or that it will actually fix any issue resulting from it.
 *
 * Thank you for your understanding.
 */

/**
 * @category Inchoo
 * @package Inchoo_Prevnext
 * @author Branko Ajzele <ajzele@gmail.com, http://foggyline.net>
 * @copyright Inchoo <http://inchoo.net>
 * @license http://opensource.org/licenses/osl-3.0.php  Open Software License (OSL 3.0)
 */
class Inchoo_Prevnext_Helper_Data extends Mage_Core_Helper_Abstract
{
    /**
     * @return Mage_Catalog_Model_Product or FALSE
     */
    public function getPreviousProduct()
    {
        $prodId = Mage::registry('current_product')->getId();

        $positions = Mage::getSingleton('core/session')->getInchooFilteredCategoryProductCollection();

        if (!$positions && Mage::registry('current_category')) {
            $current_category = Mage::registry('current_category');
            if (get_class($current_category->getResource()) != 'Mage_Catalog_Model_Resource_Category_Flat') {
                $positions = array_reverse(array_keys($current_category->getProductsPosition()));
            }
        }
        if (!$positions) {
            $positions = array();
        }

        $cpk = @array_search($prodId, $positions);

        $slice = array_reverse(array_slice($positions, 0, $cpk));

        foreach ($slice as $productId) {
            $product = Mage::getModel('catalog/product')
                ->load($productId);

            if ($product && $product->getId() && $product->isVisibleInCatalog() && $product->isVisibleInSiteVisibility()) {
                return $product;
            }
        }

        return false;
    }

    /**
     * @return Mage_Catalog_Model_Product or FALSE
     */
    public function getNextProduct()
    {
        $prodId = Mage::registry('current_product')->getId();

        $positions = Mage::getSingleton('core/session')->getInchooFilteredCategoryProductCollection();

        if (!$positions && Mage::registry('current_category')) {
            $current_category = Mage::registry('current_category');
            if (get_class($current_category->getResource()) != 'Mage_Catalog_Model_Resource_Category_Flat') {
                $positions = array_reverse(array_keys($current_category->getProductsPosition()));
            }
        }
        if (!$positions) {
            $positions = array();
        }

        $cpk = @array_search($prodId, $positions);

        $slice = array_slice($positions, $cpk + 1, count($positions));

        foreach ($slice as $productId) {
            $product = Mage::getModel('catalog/product')
                ->load($productId);

            if ($product && $product->getId() && $product->isVisibleInCatalog() && $product->isVisibleInSiteVisibility()) {
                return $product;
            }
        }

        return false;
    }
}