<?php

function post_20140705_page_slug_tiki($installer)
{
    $pages = $installer->table('tiki_pages');
    $names = $pages->fetchColumn('pageName', []);
    foreach ($names as $name) {
        try {
            $pages->update(['pageSlug' => urlencode($name)], [
                'pageName' => $name,
            ]);
        } catch (Exception $e) {
            // Presumably, Duplicate entry found. Too bad $e->getCode() returns 0
            // We need to find a pageSlug name which is not already taken
            // Shorten so we can add numbers afterwards in the form blabla…bla_42 from _0 to _999
            $prefixPageSlug = substr(urlencode($name), 0, 156);
            // Strip urlencoding %xx which might have been truncated at the end
            if (strrpos($prefixPageSlug, '%') && strrpos($prefixPageSlug, '%') >= 154) {
                $prefixPageSlug = substr($prefixPageSlug, 0, strrpos($prefixPageSlug, '%'));
            }
            for ($i = 0; $i <= 999; $i++) {
                $pageSlug = $prefixPageSlug . "_$i";
                $duplicates = $pages->fetchColumn('pageName', ['pageSlug' => $pageSlug ]);
                if (count($duplicates) == 0) {
                    $pages->update(['pageSlug' => $pageSlug], ['pageName' => $name]);
                    break;
                }
            }
        }
    }
}