<?php
namespace Concrete\Core\Utility\Service;

use Concrete\Core\Support\Facade\Application;
use Hautelook\Phpass\PasswordHash;

/**
 * \@package Helpers
 * @subpackage Validation
 *
 * @author Andrew Embler <andrew@concrete5.org>
 * @copyright  Copyright (c) 2003-2008 Concrete5. (http://www.concrete5.org)
 * @license    http://www.concrete5.org/license/     MIT License
 */

/**
 * A helper that allows the creation of unique strings, for use when creating hashes, identifiers.
 *
 * \@package Helpers
 * @subpackage Validation
 *
 * @author Andrew Embler <andrew@concrete5.org>
 * @copyright  Copyright (c) 2003-2008 Concrete5. (http://www.concrete5.org)
 * @license    http://www.concrete5.org/license/     MIT License
 */
class Identifier
{

    /**
     * Like generate() below, but simply appends an ever increasing number to what you provide
     * until it comes back as not found.
     */
    public function generateFromBase($string, $table, $key)
    {
        $foundRecord = false;
        $db = Application::make('Concrete\Core\Database\Connection\Connection');
        $i = '';
        $_string = '';
        while ($foundRecord == false) {
            $_string = $string . $i;
            $cnt = $db->GetOne("select count(" . $key . ") as total from " . $table . " where " . $key . " = ?",
                array($_string));
            if ($cnt < 1) {
                $foundRecord = true;
            } else {
                if ($i == '') {
                    $i = 0;
                }
                ++$i;
            }
        }

        return $_string;
    }

    /**
     * Generates a unique identifier for an item in a database table. Used, among other places, in generating
     * User hashes for email validation.
     *
     * @param string $table
     * @param string $key
     * @param int $length
     * @param bool $lowercase
     *
     * @return string
     */
    public function generate($table, $key, $length = 12, $lowercase = false)
    {
        $foundHash = false;
        $db = Application::make('Concrete\Core\Database\Connection\Connection');
        while ($foundHash == false) {
            $string = $this->getString($length);
            if ($lowercase) {
                $string = strtolower($string);
            }
            $cnt = $db->GetOne("select count(" . $key . ") as total from " . $table . " where " . $key . " = ?",
                array($string));
            if ($cnt < 1) {
                $foundHash = true;
            }
        }

        return $string;
    }

    /**
     * Generate a cryptographically secure random string
     * @param int $length
     * @return string
     */
    public function getString($length = 12)
    {
        if (function_exists('random_bytes')) {
            $bytes = random_bytes($length / 2);
        } else {
            $hash = new PasswordHash(8, false);
            $bytes = $hash->get_random_bytes($length / 2);
        }

        return bin2hex($bytes);
    }

    public function deleteKey($table, $keyCol, $uHash)
    {
        $db = Application::make('Concrete\Core\Database\Connection\Connection');
        $db->Execute("DELETE FROM " . $table . " WHERE " . $keyCol . "=?", array($uHash));
    }
}