<?php

class LightPressModRewrite {
    
    var $basedir;
    var $_rootdir;
    var $_htaccess;
    
    // the following are just in case we ever find a way to decode the archive permalink
    // built using strftime, as we currently only support %Y and %m
    var $_strftime_formats = array(
        '%b'    => '[a-zA-Z]+',       // abbreviated month name according to the current locale
        '%B'    => '[a-zA-Z]+',       // full month name according to the current locale
        '%C'    => '[0-9]{2}',     // century number (the year divided by 100 and truncated to an integer, range 00 to 99)
        '%h'    => '[a-zA-Z]+',       // same as %b
        '%m'    => '([0-9]{2})',   // month as a decimal number (range 01 to 12)
        '%U'    => '[0-9]{1,2}',   // week number of the current year as a decimal number, starting with the first Sunday as the first day of the first week
        '%V'    => '[0-9]{2}',     // The ISO 8601:1988 week number of the current year as a decimal number, range 01 to 53, where week 1 is the first week that has at least 4 days in the current year, and with Monday as the first day of the week. (Use %G or %g for the year component that corresponds to the week number for the specified timestamp.)
        '%W'    => '[0-9]{1,2}',   // week number of the current year as a decimal number, starting with the first Monday as the first day of the first week
        '%y'    => '([0-9]{2})',   // year as a decimal number without a century (range 00 to 99)
        '%Y'    => '([0-9]{4})'    // year as a decimal number including the century
        );
    
    var $_strftime_verbs = array(   // for conversion from selected verbs below to formats above
        '{year}'      => '%Y',
        '{monthnum}'  => '%m', 
        '{day}'       => '%d',
        '{hour}'      => '%H',
        '{minute}'    => '%M',
        '{second}'    => '%S'
        );
    
    var $_permalink_verbs = array(
        'year'          => '[0-9]{4}', 
        'monthnum'      => '[0-9]{2}', 
        'day'           => '[0-9]{2}',
        'hour'          => '[0-9]{2}',
        'minute'        => '[0-9]{2}',
        'second'        => '[0-9]{2}',
        'postname'      => '([-a-zA-Z0-9_]+)',
        'post_name'     => '([-a-zA-Z0-9_]+)',
        'post_id'       => '([0-9]+)',
        'category_id'   => '([0-9]+)',
        'category_name' => '([-a-zA-Z0-9_]+)',
        'category'      => '',  // unsupported for now, since it requires an additional JOIN in plugins
        'author'        => ''   // unsupported for now, since it requires an additional JOIN in plugins
        );
    
    function LightPressModRewrite() {
        $basedir = get_option('lp_opt_basedir');
        if (!$basedir) {
            trigger_error('LightPress active with no options set (null basedir), skipping LightPress .htaccess filter', E_USER_WARNING);
        }
        $this->basedir = $basedir;
        $this->_rootdir = dirname(dirname(dirname($basedir)));
    }
    
    function buildHtaccess($comment=false) {
        $this->_htaccess = '';
        $ht =& $this->_htaccess;
        if ($comment) {
            $c = '#';
            $ht .= "##\n## LightPress mod_rewrite rules, copy in the LP public folder and remove comments\n##\n";
        } else {
            $c = '';
        }
        $ht .= "${c}\n${c}<IfModule mod_rewrite.c>\n${c}\n${c}RewriteEngine On\n";
        $parsed_url = parse_url(get_option('siteurl'));
        if (!isset($parsed_url['path']))
            $parsed_url['path'] = '';
        $ht .= $c . 'RewriteBase ' . $parsed_url['path'] . "/wp-content/plugins/lightpress\n";
        $ht .= $c . 'RewriteCond %{REQUEST_FILENAME} -f [OR]' . "\n";
        $ht .= $c . 'RewriteCond %{REQUEST_FILENAME} -d' . "\n";
        $ht .= $this->_getIndexRules($c);
        $ht .= $this->_getFeedRules($c);
        $ht .= $this->_getTagRules($c);
        $ht .= $this->_getCategoryRules($c);
        $ht .= $this->_getArchiveRules($c);
        $ht .= $this->_getPostRules($c);
        $ht .= $this->_getEndRules($c);
        $ht .= "${c}\n${c}</IfModule>\n";
        return $ht;
    }
    
    function _getIndexRules($c) {
        $ht = "${c}\n${c}# index page\n";
        $ht .= $c . 'RewriteRule ^/?$ index.php [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^record/([0-9]+)/?$ index.php?i=$1 [QSA,L]' . "\n";
        $prefix = str_replace('?', '\\?', get_option('lp_opt_search_prefix'));
        $ht .= $c . 'RewriteRule ^' . $prefix . '/?$ index.php [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/rss2.xml/?$ feed.php?q=$1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/?$ index.php?q=$1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/record/?([0-9]*)/?$ index.php?q=$1&i=$2 [QSA,L]' . "\n";
        $prefix = str_replace('?', '\\?', get_option('lp_opt_author_prefix'));
        $ht .= $c . 'RewriteRule ^' . $prefix . '/?$ index.php [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/rss2.xml/?$ feed.php?u=$1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/?$ index.php?u=$1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/record/?([0-9]*)/?$ index.php?u=$1&i=$2 [QSA,L]' . "\n";
        $ht .= "$c\n";
        $ht .= "$c# stats\n";
        $ht .= $c . 'RewriteRule ^stats.gif$ stats.php [QSA,L]' . "\n";
        return $ht;
    }
    
    function _getFeedRules($c) {
        
        // find WP subdir(s)
        $url = get_option('lp_opt_url');
        $wp_url = get_option('lp_opt_wp_url');
        $pos = strpos($wp_url, $url);
        if (($url != $wp_url) && ($pos !== false)) {
            $pos += strlen($url) + 1;
            $base = substr($wp_url, $pos);
            if (substr($base, -1) != '/')
                $base .= '/';
        } else {
            $base = '';
        }
        
        $ht = "${c}\n${c}#feeds\n";
        # feeds
        $ht .= $c . 'RewriteRule ^rss2.xml feed.php [L]' . "\n";
        $ht .= $c . 'RewriteRule ^atom.xml feed.php?feed=atom [L]' . "\n";
        $ht .= $c . 'RewriteRule ^sitemap.xml sitemap.php?sitemap=1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^sitemap_index.xml sitemap.php [L]' . "\n";
        $ht .= "${c}\n${c}# feeds (WP compatibility)\n";
        $ht .= $c . 'RewriteRule ^' . $base . 'wp-atom.php feed.php [L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $base . 'wp-rss.php feed.php [L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $base . 'wp-rss2.php feed.php [L]' . "\n";
        $ht .= $c . 'RewriteRule ^feed$ feed.php [L]' . "\n";
        $ht .= $c . 'RewriteRule ^feed/?(feed|rss|rss2|rdf|atom)/?$ feed.php?feed=$1 [QSA,L]' . "\n";
        return $ht;
    }
    
    function _getTagRules($c) {
        $prefix = str_replace('?', '\\?', get_option('lp_opt_tag_prefix'));
        $ht = "${c}\n${c}# tag searches\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/(.+)/rss2.xml$ feed.php?tag=$1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/(.+)/atom.xml$ feed.php?tag=$1&feed=atom [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/(.+)/record/?([0-9]*)/?$ index.php?tag=$1&i=$2 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/(.+)/?$ index.php?tag=$1 [QSA,L]' . "\n";
        return $ht;
    }
    
    function _getCategoryRules($c) {
        $prefix = str_replace('?', '\\?', get_option('lp_opt_category_prefix'));
        $ht = "${c}\n${c}# categories\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/?$ index.php?c=$1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/record/?([0-9]*)/?$ index.php?c=$1&i=$2 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/rss2.xml$ feed.php?c=$1 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/atom.xml$ feed.php?c=$1&feed=atom [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)/sitemap.xml$ sitemap.php?c=$1&sitemap=1 [QSA,L]' . "\n";
        return $ht;
    }
    
    function _getArchiveRules($c) {
        $prefix = str_replace('?', '\\?', get_option('lp_opt_archives_prefix'));
        $prefix = str_replace(
            array_keys($this->_strftime_verbs),
            array_values($this->_strftime_verbs),
            $prefix);
        $prefix = str_replace(
            array_keys($this->_strftime_formats),
            array_values($this->_strftime_formats),
            $prefix);
        // we assume %Y and %m never swap position
        // TODO: find a way to interpret a few more strftime codes
        //       and detect the position of %Y %m to correctly place
        //       y=$n m=$n
        $ht = "${c}\n${c}# archives\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/?$ index.php?y=$1&m=$2 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/record/?([0-9]*)/?$ index.php?y=$1&m=$2&i=$3 [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/sitemap.xml$ sitemap.php?y=$1&m=$2&sitemap=1 [QSA,L]' . "\n";
        return $ht;
    }
    
    function _getPostRules($c) {
        $prefix = str_replace('?', '\\?', get_option('lp_opt_post_prefix'));
        $get_vars = array();
        $m = array();
        preg_match_all('/{([^}]+)}/', $prefix, $m, PREG_SET_ORDER);
        foreach ($m as $match) {
            list($curly_token, $token) = $match;
            if (!isset($this->_permalink_verbs[$token]))
                continue;
            $prefix = str_replace($curly_token, $this->_permalink_verbs[$token], $prefix);
            switch ($token) {
                case 'postname':
                case 'post_name':
                    $get_vars[] = 'p=$' . (count($get_vars) + 1);
                    break;
                case 'post_id':
                    $get_vars[] = 'pi=$' . (count($get_vars) + 1);
                    break;
            }
        }
        
        $ht = "${c}\n${c}# posts\n";
        $ht .= $c . 'RewriteRule ^' . $prefix . '/?$ index.php?' . implode('&', $get_vars) . ' [QSA,L]' . "\n";
        $ht .= $c . 'RewriteRule ^trackback/([^/]+)/?$ index.php?p=$1&action=trackback [QSA,L]' . "\n";
        $prefix = str_replace('?', '\\?', get_option('lp_opt_pages_prefix'));
        $suffix = get_option('lp_opt_pages_suffix');
        if ($prefix)
            $ht .= $c . 'RewriteRule ^' . $prefix . '/([^/]+)' . $suffix . '/?$ index.php?s=$1 [QSA,L]' . "\n";
        return $ht;
    }
    
    function _getEndRules($c) {

        $suffix = get_option('lp_opt_pages_suffix');
        if (!$suffix)
            $suffix = '';
        $pre = $c . 'RewriteCond %{REQUEST_FILENAME} !-f' . "\n" .
            $c . 'RewriteCond %{REQUEST_FILENAME} !-d' . "\n";
        $ht = '';
        
        # end rules
        $ht .= "\n" . $c . '#catchall rules for parent (1st level) category/pages' . "\n";
        $ht .= $pre . $c . 'RewriteRule ^([^/]+)' . $suffix . '/?$ index.php?y1=$1 [QSA,L]' . "\n";
        $ht .= $pre . $c . 'RewriteRule ^([^/]+)' . $suffix . '/record/?([0-9]*)/?$/?$ index.php?y1=$1&i=$2 [QSA,L]' . "\n";
        
        $ht .= "\n" . $c . '#catchall rules for subparent/child (2nd level) category/pages' . "\n";
        $ht .= $pre . $c . 'RewriteRule ^([^/]+)/([^/]+)' . $suffix . '/?$ index.php?y1=$1&y2=$2 [QSA,L]' . "\n";
        $ht .= $pre . $c . 'RewriteRule ^([^/]+)/([^/]+)' . $suffix . '/record/?([0-9]*)/?$/?$ index.php?y1=$1&y2=$2&i=$3 [QSA,L]' . "\n";
        
        $ht .= "\n" . $c . '#catchall rules for child (3rd level) category/pages' . "\n";
        $ht .= $pre . $c . 'RewriteRule ^([^/]+)/([^/]+)/([^/]+)' . $suffix . '/?$ index.php?y1=$1&y2=$2&y3=$3 [QSA,L]' . "\n";
        $ht .= $pre . $c . 'RewriteRule ^([^/]+)/([^/]+)/([^/]+)' . $suffix . '/record/?([0-9]*)/?$/?$ index.php?y1=$1&y2=$2&y3=$3&i=$4 [QSA,L]' . "\n";
        
        return $ht;
    }
    
    function raiseError($message, $method, $line, $type=E_USER_WARNING) {
        trigger_error(
            sprintf("%s.%s() line %d: %s", get_class($this), $method, $line, $message),
            $type);
    }
  
}

?>