<?php

// (c) Copyright by authors of the Tiki Wiki CMS Groupware Project
//
// All Rights Reserved. See copyright.txt for details and a complete list of authors.
// Licensed under the GNU LESSER GENERAL PUBLIC LICENSE. See license.txt for details.
// $Id$

class TikiDb_Initializer
{
    private $connectors = [
        'pdo' => 'TikiDb_Initializer_Pdo',
        'adodb' => 'TikiDb_Initializer_Adodb',
    ];
    private $preferred;
    private $initializeCallback;

    public function setPreferredConnector($connector)
    {
        if (isset($this->connectors[$connector])) {
            $this->preferred = $connector;
        }
    }

    public function setInitializeCallback($callback)
    {
        $this->initializeCallback = $callback;
    }

    public function getConnection(array $credentials)
    {
        if ($connector = $this->getInitializer($this->preferred)) {
            return $this->initialize($connector, $credentials);
        }

        foreach (array_keys($this->connectors) as $name) {
            if ($connector = $this->getInitializer($name)) {
                return $this->initialize($connector, $credentials);
            }
        }
    }

    private function initialize($connector, $credentials)
    {
        if ($db = $connector->getConnection($credentials)) {
            if ($callback = $this->initializeCallback) {
                $callback($db);
            }

            return $db;
        }
    }

    private function getInitializer($name)
    {
        if (! isset($this->connectors[$name])) {
            return false;
        }

        $connector = new $this->connectors[$name]();
        if ($connector->isSupported()) {
            return $connector;
        }
    }
}