<?php

/**
 * @package     Kunena.Site
 * @subpackage  com_kunena
 *
 * @copyright   Copyright (C) 2005 - 2019 Open Source Matters, Inc. All rights reserved.
 * @license     GNU General Public License version 2 or later; see LICENSE.txt
 */

namespace Kunena\Forum\Site\Service;

\defined('_JEXEC') or die;

use Exception;
use Joomla\CMS\Application\SiteApplication;
use Joomla\CMS\Categories\CategoryFactoryInterface;
use Joomla\CMS\Component\ComponentHelper;
use Joomla\CMS\Component\Router\RouterView;
use Joomla\CMS\Component\Router\RouterViewConfiguration;
use Joomla\CMS\Component\Router\Rules\StandardRules;
use Joomla\CMS\Factory;
use Joomla\CMS\Menu\AbstractMenu;
use Joomla\CMS\Profiler\Profiler;
use Joomla\Database\DatabaseInterface;
use Kunena\Forum\Libraries\Config\KunenaConfig;
use Kunena\Forum\Libraries\Forum\Category\KunenaCategoryHelper;
use Kunena\Forum\Libraries\Forum\KunenaForum;
use Kunena\Forum\Libraries\Forum\Topic\KunenaTopicHelper;
use Kunena\Forum\Libraries\Profiler\KunenaProfiler;
use Kunena\Forum\Libraries\Route\KunenaRoute;
use Kunena\Forum\Libraries\User\KunenaUserHelper;

/**
 * Routing class of com_kunena
 *
 * @since   6.0
 */
class Router extends RouterView
{
    protected $noIDs = false;

    /**
     * The category factory
     *
     * @var CategoryFactoryInterface
     *
     * @since   6.0
     */
    private $categoryFactory;

    /**
     * The db
     *
     * @var DatabaseInterface
     *
     * @since   6.0
     */
    private $db;

    /**
     * Kunena Component router constructor
     *
     * @param   SiteApplication  $app   The application object
     * @param   AbstractMenu     $menu  The menu object to work with
     *
     * @since   6.0
     */
    public function __construct(SiteApplication $app, AbstractMenu $menu)
    {
        $params      = ComponentHelper::getParams('com_kunena');
        $this->noIDs = (bool) $params->get('sef_ids');

        $kunena = new RouterViewConfiguration('kunena');
        $kunena->setKey('id');
        $this->registerView($kunena);

        parent::__construct($app, $menu);

        $this->attachRule(new StandardRules($this));
    }

    /**
     * @return  \Kunena\Forum\Site\Service\Router|null
     *
     * @since   Kunena 6.0
     *
     * @throws  Exception
     */
    public static function getInstance()
    {
        static $instance = null;

        if (!$instance) {
            if (!$instance) {
                $instance = new Router();
                $instance->load();
            }
        }

        return $instance;
    }

    /**
     * Build SEF URL
     *
     * All SEF URLs are formatted like this:
     *
     * http://site.com/menuitem/category/10-subject/[view]/[layout]/[param1]-value1/[param2]-value2?param3=value3&param4=value4
     *
     * - If catid exists, category will always be in the first segment
     * - If there is no catid, second segment for message will not be used (param-value: id-10)
     * - [view] and [layout] are the only parameters without value
     * - all other segments (task, id, userid, page, sel) are using param-value format
     *
     * NOTE! Only major variables are using SEF segments
     *
     * @param   array  $query  query
     *
     * @return  array Segments
     *
     * @since   Kunena 6.0
     *
     * @throws  Exception
     */
    public function build(&$query)
    {
        $segments = [];

        // If Kunena Forum isn't installed or SEF is not enabled, do nothing
        if (!class_exists('Kunena\Forum\Libraries\Forum\KunenaForum') || !KunenaForum::isCompatible('7.0') || !KunenaForum::installed() || !KunenaConfig::getInstance()->sef) {
            return $segments;
        }

        KUNENA_PROFILER ? KunenaProfiler::instance()->start('function ' . __FUNCTION__ . '()') : null;

        // Get menu item
        $menuitem = null;

        if (isset($query['Itemid'])) {
            static $menuitems = [];
            $Itemid = $query['Itemid'] = (int) $query['Itemid'];

            if (!isset($menuitems[$Itemid])) {
                $menuitems[$Itemid] = Factory::getApplication()->getMenu()->getItem($Itemid);

                if (!$menuitems[$Itemid]) {
                    // Itemid doesn't exist or is invalid
                    unset($query['Itemid']);
                }
            }

            $menuitem = $menuitems[$Itemid];
        }

        // Safety check: we need view in order to create SEF URLs
        if (!isset($menuitem->query['view']) && empty($query['view'])) {
            KUNENA_PROFILER ? KunenaProfiler::instance()->stop('function ' . __FUNCTION__ . '()') : null;

            return $segments;
        }

        // Get view for later use (query wins menu item)
        $view = isset($query['view']) ? (string) preg_replace('/[^a-z]/', '', $query['view']) : $menuitem->query['view'];

        // Get default values for URI variables
        if (isset(KunenaRoute::$views[$view])) {
            $defaults = KunenaRoute::$views[$view];
        }

        // Check all URI variables and remove those which aren't needed
        foreach ($query as $var => $value) {
            if (isset($defaults[$var]) && !isset($menuitem->query[$var]) && $value == $defaults[$var]) {
                // Remove URI variable which has default value
                unset($query[$var]);
            } elseif (isset($menuitem->query[$var]) && $value == $menuitem->query[$var] && $var != 'Itemid' && $var != 'option') {
                // Remove URI variable which has the same value as menu item
                unset($query[$var]);
            }
        }

        // We may have catid also in the menu item (it will not be in URI)
        $numeric = !empty($menuitem->query['catid']);
        $pos     = 0;

        // Support URIs like: /forum/category
        if (!empty($query['catid']) && ($view == 'category' || $view == 'topic' || $view == 'home')) {
            // TODO: ensure that we have view=category/topic
            $catid = (int) $query['catid'];

            if ($catid) {
                $numeric = true;

                $alias = KunenaCategoryHelper::get($catid)->alias;

                // If category alias is empty, use category id; otherwise use alias
                $segments[] = empty($alias) ? $catid : $alias;

                // This segment fully defines category view so the variable is no longer needed
                if ($view == 'category') {
                    unset($query['view']);
                }
            } elseif ($query['catid'] == '@') {
                $numeric    = true;
                $segments[] = '%' . ++$pos . '$s';

                if ($view == 'category') {
                    unset($query['view']);
                }
            }

            unset($query['catid']);
        }

        // Support URIs like: /forum/category/123-topic
        if (!empty($query['id']) && $numeric) {
            $id = (int) $query['id'];

            if ($id) {
                $subject = KunenaRoute::stringURLSafe(KunenaTopicHelper::get($id)->subject);

                if (empty($subject)) {
                    $segments[] = $id;
                } else {                    
                    $segments[] = "{$id}-{$subject}";
                }

                // This segment fully defines topic view so the variable is no longer needed
                if ($view == 'topic') {
                    unset($query['view']);
                }
            } elseif ($query['id'] == '@') {
                $segments[] = '%' . ++$pos . '$s';

                // This segment fully defines topic view so the variable is no longer needed
                if ($view == 'topic') {
                    unset($query['view']);
                }
            }

            unset($query['id']);
        } else {
            // No id available, do not use numeric variable for mesid
            $numeric = false;
        }

        // View gets added only when we do not use short URI for category/topic
        if (!empty($query['view'])) {
            // Use filtered value
            $segments[] = $view;

            // Handle attachment ID
            if ($view == 'attachment') {
                if (!empty($query['id'])) {
                    // Use filtered value
                    $segments[] = (int) $query['id'];
                    unset($query['id']);
                }

                if (!empty($query['thumb'])) {
                    // Use filtered value
                    $segments[] = 'thumb';
                    unset($query['thumb']);
                }

                unset($query['format']);

                if (!empty($query['filename'])) {
                    $segments[] = $query['filename'];
                    unset($query['filename']);
                }
            }
        }

        // Support URIs like: /forum/category/123-topic/reply
        if (!empty($query['layout'])) {
            // Use filtered value
            $segments[] = (string) preg_replace('/[^a-z]/', '', $query['layout']);
        }

        // Support URIs like: /forum/category/123-topic/reply/124
        if (isset($query['mesid']) && $numeric) {
            if ($query['mesid'] == '@') {
                $segments[] = '%' . ++$pos . '$s';
            } else {
                $segments[] = (int) $query['mesid'];
            }

            unset($query['mesid']);
        }

        // Support URIs like: /forum/user/128-matias
        if (isset($query['userid']) && $view == 'user') {
            if ($query['userid'] == '@') {
                $segments[] = '%' . ++$pos . '$s';
            } else {
                $segments[] = (int) $query['userid'] . '-' . KunenaRoute::stringURLSafe(KunenaUserHelper::get((int) $query['userid'])->getName());
            }

            unset($query['userid']);
        }

        unset($query['view'], $query['layout']);

        // Rest of the known parameters are in var-value form
        foreach (KunenaRoute::$parsevars as $var => $dummy) {
            if (isset($query[$var])) {
                $segments[] = "{$var}-{$query[$var]}";
                unset($query[$var]);
            }
        }

        if (isset($query['start']) && $query['start'] == '@' && $query['start'] !== 0) {
            $query['start'] = '%' . ++$pos . '$d';
        }

        KUNENA_PROFILER ? KunenaProfiler::instance()->stop('function ' . __FUNCTION__ . '()') : null;

        return $segments;
    }

    /**
     * @param   array  $segments  segments
     *
     * @return  array
     *
     * @since   Kunena 6.0
     *
     * @throws  Exception
     */
    public function parse(&$segments)
    {
        // If Kunena Forum isn't installed do nothing
        if (!class_exists('Kunena\Forum\Libraries\Forum\KunenaForum') || !KunenaForum::isCompatible('7.0') || !KunenaForum::installed()) {
            return [];
        }

        $total = \count($segments);

        for ($i = 0; $i < $total; $i++) {
            $segments[$i] = preg_replace('/-/', ':', $segments[$i], 1);
        }

        $profiler = Profiler::getInstance('Application');
        KUNENA_PROFILER ? $profiler->mark('kunenaRoute') : null;
        $starttime = microtime(true);

        // Get current menu item and get query variables from it
        $active = Factory::getApplication()->getMenu()->getActive();
        $vars   = isset($active->query) ? $active->query : ['view' => 'home'];

        if (empty($vars['view']) || $vars['view'] == 'home' || $vars['view'] == 'entrypage') {
            $vars['view'] = '';
        }

        // Use category SEF feature?
        $sefcats = isset(KunenaRoute::$sefviews[$vars['view']]) && empty($vars['id']);

        // Handle all segments
        while (($segment = array_shift($segments)) !== null) {
            // Skip //
            if (!$segment) {
                continue;
            }

            if ($sefcats && class_exists('Kunena\Forum\Libraries\Route\KunenaRoute') && method_exists('Kunena\Forum\Libraries\Route\KunenaRoute', 'resolveAlias')) {
                // Find out if we have SEF alias (category, view or layout)
                $alias     = strtr($segment, ':', '-');
                $variables = KunenaRoute::resolveAlias($alias);
                
                if ($variables) {
                    $sefcats = false;
                    $vars    = $variables + $vars;
                    continue;
                }
            }

            $sefcats = false;

            // Generate variable and value
            $seg   = explode(':', $segment);
            $var   = array_shift($seg);
            $value = array_shift($seg);

            if (empty($var) && empty($value)) {
                // Skip /-/
                continue;
            }

            if (is_numeric($var)) {
                // Handle variables starting by number
                $value = (int) $var;

                if ($vars['view'] == 'user') {
                    // Special case: User view
                    $var = 'userid';
                } elseif (empty($vars['catid'])) {
                    // First number is always category
                    $var          = 'catid';
                    $vars['view'] = 'category';
                } elseif (empty($vars['id'])) {
                    // Second number is always topic
                    $var          = 'id';
                    $vars['view'] = 'topic';
                    $sefcats      = false;
                } elseif (empty($vars['mesid'])) {
                    // Third number is always message
                    $var          = 'mesid';
                    $vars['view'] = 'topic';
                } else {
                    // Invalid parameter, skip it
                    continue;
                }
            } elseif ($value === null) {
                // Simple variable without value is always either view or layout
                $value = $var;

                if (empty($vars['view']) || ($value == 'topic' && $vars['view'] == 'category')) {
                    // View
                    $var = 'view';
                } elseif (empty($vars['layout'])) {
                    // Layout
                    $var = 'layout';
                } elseif (!empty($vars['view'])) {
                    // Unknown parameter: skip
                    if (!empty($vars['view'])) {
                        continue;
                    }
                } else {
                    // Unknown view or non-existing category
                    $var = 'view';
                }
            }

            $vars[$var] = $value;

            // Handle attachment ID
            if ($var == 'view' && $value == 'attachment') {
                $segment    = array_shift($segments);
                $vars['id'] = (int) $segment;
                $segment    = array_shift($segments);

                if ($segment) {
                    $vars[$segment] = 1;
                }

                $vars['format'] = 'raw';
            }
        }

        if (empty($vars['layout'])) {
            $vars['layout'] = 'default';
        }

        KunenaRoute::$time = microtime(true) - $starttime;

        foreach ($vars as $var => $value) {
            KunenaRoute::$current->setVar($var, $value);
        }

        return $vars;
    }
}