<?php
/*
Plugin Name: Create Topic Slugs
Description:  Creates topic slugs where previously there weren't any. Outputs into error log, only works on plugin activation.
Plugin URI:  http://simonwheatley.co.uk/bbpress/create-topic-slugs
Author: simonwheatley
Author URI: http://simonwheatley.co.uk
Version: 1
*/

class CreateTopicSlugs
{
    function __construct()
    {
        global $bbdb;
        $this->db = & $bbdb;
    }
    
    public function create_slugs()
    {
        $topics = $this->slugless_topics();
        if ( ! count( $topics ) ) {
            echo "All topics now have slugs, you can disable the create topic slugs plugin by removing it from the plugins directory.";
            exit;
        }
        foreach( $topics AS $topic ) {
            $new_topic_slug = $this->generate_topic_slug( $topic->topic_id, $topic->topic_title );
            $this->update_topic_slug( $topic->topic_id, $new_topic_slug );
        }
    }
    
    protected function slugless_topics()
    {
        // Just do 300 at a time for now
        $topics_table = $this->db->topics;
        $sql = " SELECT topic_id, topic_title FROM $topics_table WHERE topic_slug IS NULL OR topic_slug = '' LIMIT 1000 ";
        // No need to prepared the SQL, no user input
        return $this->db->get_results( $sql );
    }
    
    protected function generate_topic_slug( $topic_id, $topic_title )
    {
        $topic_slug = $_topic_slug = bb_slug_sanitize( wp_specialchars_decode( $topic_title, ENT_QUOTES ) );
        if ( strlen( $_topic_slug ) < 1 ) $topic_slug = $_topic_slug = '0';

        // Ensure the slug is unique
        while ( is_numeric( $topic_slug ) || $existing_slug = $this->existing_slug( $topic_id, $topic_slug ) ) {
            $topic_slug = bb_slug_increment( $_topic_slug, $existing_slug );
        }
        return $topic_slug;
    }
    
    protected function existing_slug( $topic_id, $topic_slug )
    {
        $topics_table = $this->db->topics;
        $sql = "SELECT topic_slug FROM $topics_table WHERE topic_slug = %s AND topic_id != %d";
        $prepared_sql = $this->db->prepare( $sql, $topic_slug, $topic_id );
        return $this->db->get_var( $prepared_sql );
    }
    
    protected function update_topic_slug( $topic_id, $topic_slug )
    {
        $topic_table = $this->db->topics;
        $data = array( 'topic_slug' => $topic_slug );
        $where = array( 'topic_id' => $topic_id );
        $this->db->update( $topic_table, $data, $where );
    }

}

$create_topic_slugs = new CreateTopicSlugs();

add_action( 'bb_init', array( & $create_topic_slugs, 'create_slugs' ) );

?>