<?php
/**
* @version		$Id: pagenavigation.php 14401 2010-01-26 14:10:00Z louis $
* @package		Joomla
* @copyright	Copyright (C) 2005 - 2010 Open Source Matters. All rights reserved.
* @license		GNU/GPL, see LICENSE.php
* Joomla! is free software. This version may have been modified pursuant
* to the GNU General Public License, and as distributed it includes or
* is derivative of works licensed under the GNU General Public License or
* other free or open source software licenses.
* See COPYRIGHT.php for copyright notices and details.
*/

// no direct access
defined( '_JEXEC' ) or die( 'Restricted access' );

$mainframe->registerEvent( 'onBeforeDisplayContent', 'plgContentNavigation' );

function plgContentNavigation( &$row, &$params, $page=0 )
{
	$view		= JRequest::getCmd('view');

	// Get Plugin info
	$plugin =& JPluginHelper::getPlugin('content', 'pagenavigation');

	if ($params->get('show_item_navigation') && ($view == 'article'))
	{

		$html 		= '';
		$db 		= & JFactory::getDBO();
		$user		= & JFactory::getUser();
		$nullDate	= $db->getNullDate();

		$date		=& JFactory::getDate();
		$config 	= & JFactory::getConfig();
		$now 		= $date->toMySQL();

		$uid 		= $row->id;
		$option 	= 'com_content';
		$canPublish = $user->authorize('com_content', 'publish', 'content', 'all');

		// the following is needed as different menu items types utilise a different param to control ordering
		// for Blogs the `orderby_sec` param is the order controlling param
		// for Table and List views it is the `orderby` param
		$params_list = $params->toArray();
		if (array_key_exists('orderby_sec', $params_list)) {
			$order_method = $params->get('orderby_sec', '');
		} else {
			$order_method = $params->get('orderby', '');
		}
		// additional check for invalid sort ordering
		if ( $order_method == 'front' ) {
			$order_method = '';
		}

		// Determine sort order
		switch ($order_method)
		{
			case 'date' :
				$orderby = 'a.created';
				break;

			case 'rdate' :
				$orderby = 'a.created DESC';
				break;

			case 'alpha' :
				$orderby = 'a.title';
				break;

			case 'ralpha' :
				$orderby = 'a.title DESC';
				break;

			case 'hits' :
				$orderby = 'a.hits';
				break;

			case 'rhits' :
				$orderby = 'a.hits DESC';
				break;

			case 'order' :
				$orderby = 'a.ordering';
				break;

			case 'author' :
				$orderby = 'a.created_by_alias, u.name';
				break;

			case 'rauthor' :
				$orderby = 'a.created_by_alias DESC, u.name DESC';
				break;

			case 'front' :
				$orderby = 'f.ordering';
				break;

			default :
				$orderby = 'a.ordering';
				break;
		}

		$xwhere = ' AND ( a.state = 1 OR a.state = -1 )' .
		' AND ( publish_up = '.$db->Quote($nullDate).' OR publish_up <= '.$db->Quote($now).' )' .
		' AND ( publish_down = '.$db->Quote($nullDate).' OR publish_down >= '.$db->Quote($now).' )';

		// array of articles in same category correctly ordered
		$query = 'SELECT a.id,'
		. ' CASE WHEN CHAR_LENGTH(a.alias) THEN CONCAT_WS(":", a.id, a.alias) ELSE a.id END as slug,'
		. ' CASE WHEN CHAR_LENGTH(cc.alias) THEN CONCAT_WS(":", cc.id, cc.alias) ELSE cc.id END as catslug'
		. ' FROM #__content AS a'
		. ' LEFT JOIN #__categories AS cc ON cc.id = a.catid'
		. ' WHERE a.catid = ' . (int) $row->catid
		. ' AND a.state = '. (int) $row->state
		. ($canPublish ? '' : ' AND a.access <= ' .(int) $user->get('aid', 0))
		. $xwhere
		. ' ORDER BY '. $orderby;
		$db->setQuery($query);
		$list = $db->loadObjectList('id');

		// this check needed if incorrect Itemid is given resulting in an incorrect result
		if ( !is_array($list) ) {
			$list = array();
		}

		reset($list);

		// location of current content item in array list
		$location = array_search($uid, array_keys($list));

		$rows = array_values($list);

		$row->prev = null;
		$row->next = null;

		if ($location -1 >= 0) 	{
			// the previous content item cannot be in the array position -1
			$row->prev = $rows[$location -1];
		}

		if (($location +1) < count($rows)) {
			// the next content item cannot be in an array position greater than the number of array postions
			$row->next = $rows[$location +1];
		}

		$pnSpace = "";
		if (JText::_('&lt') || JText::_('&gt')) {
			$pnSpace = " ";
		}

		if ($row->prev) {
			$row->prev = JRoute::_(ContentHelperRoute::getArticleRoute($row->prev->slug, $row->prev->catslug));
		} else {
			$row->prev = '';
		}

		if ($row->next) {
			$row->next = JRoute::_(ContentHelperRoute::getArticleRoute($row->next->slug, $row->next->catslug));
		} else {
			$row->next = '';
		}


		// output
		if ($row->prev || $row->next)
		{
			$html = '
			<table align="center" class="pagenav">
			<tr>'
			;
			if ($row->prev)
			{
				$html .= '
				<th class="pagenav_prev">
					<a href="'. $row->prev .'">'
						. JText::_( '&lt' ) . $pnSpace . JText::_( 'Prev' ) . '</a>
				</th>'
				;
			}

			if ($row->prev && $row->next)
			{
				$html .= '
				<td width="50">
					&nbsp;
				</td>'
				;
			}

			if ($row->next)
			{
				$html .= '
				<th class="pagenav_next">
					<a href="'. $row->next .'">'
						. JText::_( 'Next' ) . $pnSpace . JText::_( '&gt' ) .'</a>
				</th>'
				;
			}
			$html .= '
			</tr>
			</table>'
			;

			// Get the plugin parameters
			$pluginParams = new JParameter( $plugin->params );
			$position 	 = $pluginParams->get('position', 1);

			if ($position) {
			// display after content
				$row->text .= $html;
			} else {
			// display before content
				$row->text = $html . $row->text;
			}
		}
	}

	return ;
}
