<?php
/**
 * File:
 * class.modrewriteurlstack.php
 *
 * ModRewrite url stack class
 * 
 * @category ConLite
 * @package Plugin
 * @subpackage ModRewrite
 * @since 2.1.3
 * @author Ortwin Pinke <o.pinke@conlite.org>
 * @copyright (c) 2022, conlite.org
 * @license http://www.gnu.de/documents/gpl.en.html GPL v3 (english version)
 * @license http://www.gnu.de/documents/gpl.de.html GPL v3 (deutsche Version)
 * @link http://www.conlite.org ConLite.org
 * 
 * based on former AMR class by  Murat Purc <murat@purc.de> for  CONTENIDO 4.8.x
 */
if (!defined('CON_FRAMEWORK')) {
    die('Illegal call');
}

class ModRewriteUrlStack {

    /**
     * Self instance
     *
     * @var  ModRewriteUrlStack
     */
    private static $_oInstance;

    /**
     * Database object
     *
     * @var  DB_Contenido
     */
    private $_oDb;

    /**
     * Array for urls
     *
     * @var  array
     */
    private $_aUrls = array();

    /**
     * Url stack array
     *
     * @var  array
     */
    private $_aStack = array();

    /**
     * CONTENIDO related parameter array
     *
     * @var  array
     */
    private $_aConParams = array(
        'idcat' => 1, 'idart' => 1, 'lang' => 1, 'idcatlang' => 1, 'idcatart' => 1, 'idartlang' => 1
    );

    /**
     * Database tables array
     *
     * @var  array
     */
    private $_aTab;

    /**
     * Language id
     *
     * @var  int
     */
    private $_idLang;

    /**
     * Constructor, sets some properties.
     */
    private function __construct() {
        $this->_oDb = cRegistry::getDb();
        $this->_aTab = cRegistry::getConfigValue('tab');
        $this->_idLang = cRegistry::getLanguageId();
    }

    /**
     * Returns a instance of ModRewriteUrlStack (singleton implementation)
     *
     * @return  ModRewriteUrlStack
     */
    public static function getInstance() {
        if (self::$_oInstance == null) {
            self::$_oInstance = new ModRewriteUrlStack();
        }
        return self::$_oInstance;
    }

    /**
     * Adds an url to the stack
     *
     * @param  string  Url, like front_content.php?idcat=123...
     */
    public function add($url) {
        $url = ModRewrite::urlPreClean($url);
        if (isset($this->_aUrls[$url])) {
            return;
        }

        $aUrl = $this->_extractUrl($url);

        // cleanup parameter
        foreach ($aUrl['params'] as $p => $v) {
            if (!isset($this->_aConParams[$p])) {
                unset($aUrl['params'][$p]);
            } else {
                $aUrl['params'][$p] = (int) $v;
            }
        }

        // add language id, if not available
        if ((int) mr_arrayValue($aUrl['params'], 'lang') == 0) {
            $aUrl['params']['lang'] = $this->_idLang;
        }

        $sStackId = $this->_makeStackId($aUrl['params']);
        $this->_aUrls[$url] = $sStackId;
        $this->_aStack[$sStackId] = array('params' => $aUrl['params']);
    }

    /**
     * Returns the pretty urlparts (only category path an article name) of the
     * desired url.
     *
     * @param   string  Url, like front_content.php?idcat=123...
     * @return  array   Assoziative array like
     * <code>
     * $arr['urlpath']
     * $arr['urlname']
     * </code>
     */
    public function getPrettyUrlParts($url) {
        $url = ModRewrite::urlPreClean($url);
        if (!isset($this->_aUrls[$url])) {
            $this->add($url);
        }

        $sStackId = $this->_aUrls[$url];
        if (!isset($this->_aStack[$sStackId]['urlpath'])) {
            $this->_chunkSetPrettyUrlParts($sStackId);
        }
        $aPretty = array(
            'urlpath' => (empty($this->_aStack[$sStackId]['urlpath']))?'':$this->_aStack[$sStackId]['urlpath'],
            'urlname' => (empty($this->_aStack[$sStackId]['urlname']))?'':$this->_aStack[$sStackId]['urlname']
        );
        return $aPretty;
    }

    /**
     * Extracts passed url using parse_urla and adds also the 'params' array to it
     *
     * @param   string  Url, like front_content.php?idcat=123...
     * @return  array  Components containing result of parse_url with additional
     *                 'params' array
     */
    private function _extractUrl($url) {
        $aUrl = @parse_url($url);
        if (isset($aUrl['query'])) {
            $aUrl['query'] = str_replace('&amp;', '&', $aUrl['query']);
            parse_str($aUrl['query'], $aUrl['params']);
        }
        if (empty($aUrl['params']) || !is_array($aUrl['params'])) {
            $aUrl['params'] = array();
        }
        return $aUrl;
    }

    /**
     * Extracts article or category related parameter from passed params array
     * and generates an identifier.
     *
     * @param   array   $aParams  Parameter array
     * @return  string  Composed stack id
     */
    private function _makeStackId(array $aParams) {
        # idcatart
        if ((int) mr_arrayValue($aParams, 'idart') > 0) {
            $sStackId = 'idart_' . $aParams['idart'] . '_lang_' . $aParams['lang'];
        } elseif ((int) mr_arrayValue($aParams, 'idartlang') > 0) {
            $sStackId = 'idartlang_' . $aParams['idartlang'];
        } elseif ((int) mr_arrayValue($aParams, 'idcatart') > 0) {
            $sStackId = 'idcatart_' . $aParams['idcatart'] . '_lang_' . $aParams['lang'];
        } elseif ((int) mr_arrayValue($aParams, 'idcat') > 0) {
            $sStackId = 'idcat_' . $aParams['idcat'] . '_lang_' . $aParams['lang'];
        } elseif ((int) mr_arrayValue($aParams, 'idcatlang') > 0) {
            $sStackId = 'idcatlang_' . $aParams['idcatlang'];
        } else {
            $sStackId = 'lang_' . $aParams['lang'];
        }
        return $sStackId;
    }

    /**
     * Main function to get the urlparts of urls.
     *
     * Composes the query by looping thru stored but non processed urls, executes
     * the query and adds the (urlpath and urlname) result to the stack.
     * 
     * @param type $sStackId
     * @return type
     */
    private function _chunkSetPrettyUrlParts($sStackId) {
        if (!isset($this->_aStack[$sStackId]) || isset($this->_aStack[$sStackId]['urlpath'])) {
            return;
        }

        $aStack = [];
        $aStack[$sStackId] = $this->_aStack[$sStackId];

        // now, it's time to compose the where clause of the query
        $sWhere = '';
        $aP = $this->_aStack[$sStackId]['params'];
        if ((int) mr_arrayValue($aP, 'idart') > 0) {
            $sWhere .= '(al.idart = ' . $aP['idart'] . ' AND al.idlang = ' . $aP['lang'] . ') OR ';
        } elseif ((int) mr_arrayValue($aP, 'idartlang') > 0) {
            $sWhere .= '(al.idartlang = ' . $aP['idartlang'] . ') OR ';
        } elseif ((int) mr_arrayValue($aP, 'idcat') > 0) {
            $sWhere .= '(cl.idcat = ' . $aP['idcat'] . ' AND cl.idlang = ' . $aP['lang'] . ' AND cl.startidartlang = al.idartlang) OR ';
        } elseif ((int) mr_arrayValue($aP, 'idcatart') > 0) {
            $sWhere .= '(ca.idcatart = ' . $aP['idcatart'] . ' AND ca.idart = al.idart AND al.idlang = ' . $aP['lang'] . ') OR ';
        } elseif ((int) mr_arrayValue($aP, 'idcatlang') > 0) {
            $sWhere .= '(cl.idcatlang = ' . $aP['idcatlang'] . ' AND cl.startidartlang = al.idartlang) OR ';
        }
        if ($sWhere == '') {
            return;
        }
        $sWhere = cString::getPartOfString($sWhere, 0, -4);
        $sWhere = str_replace(' OR ', " OR \n", $sWhere);

        // compose query and execute it
        $sql = <<<SQL
SELECT
        al.idartlang, al.idart, al.idlang as lang, al.urlname, cl.idcatlang, cl.idcat,
        cl.urlpath, ca.idcatart
FROM
        {$this->_aTab['art_lang']} AS al, {$this->_aTab['cat_lang']} AS cl, {$this->_aTab['cat_art']} AS ca
WHERE
        al.idart = ca.idart AND
        ca.idcat = cl.idcat AND
        al.idlang = cl.idlang AND
        ( $sWhere )
SQL;
        ModRewriteDebugger::add($sql, 'ModRewriteUrlStack->_chunkSetPrettyUrlParts() $sql');

        $aNewStack = [];

        // create array of fields, which are to reduce step by step from record set below
        $aFields = array('', 'idart', 'idartlang', 'idcatart', 'idcat');

        $this->_oDb->query($sql);
        while ($this->_oDb->next_record()) {
            $aRS = $this->_oDb->Record;

            // loop thru fields array
            foreach ($aFields as $field) {
                if (isset($aRS[$field])) {
                    // reduce existing field
                    unset($aRS[$field]);
                }

                // matching stack entry found, add urlpath and urlname to the new stack
                $aNewStack[$sStackId]['urlpath'] = $aRS['urlpath'];
                $aNewStack[$sStackId]['urlname'] = $aRS['urlname'];
            }
        }
        ModRewriteDebugger::add($aNewStack, 'ModRewriteUrlStack->_chunkSetPrettyUrlParts() $aNewStack');
        ModRewriteDebugger::add($this->_aStack, 'ModRewriteUrlStack->_chunkSetPrettyUrlParts() $this->_aStack');

        $this->_aStack = array_merge($this->_aStack, $aNewStack);
    }
}