<?php
/**
 * Copyright 2010-2013 Amazon.com, Inc. or its affiliates. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License").
 * You may not use this file except in compliance with the License.
 * A copy of the License is located at
 *
 * http://aws.amazon.com/apache2.0
 *
 * or in the "license" file accompanying this file. This file is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
 * express or implied. See the License for the specific language governing
 * permissions and limitations under the License.
 */

namespace Aws\Common;

use Guzzle\Service\Builder\ServiceBuilder;
use Guzzle\Service\Builder\ServiceBuilderLoader;

/**
 * Base class for interacting with web service clients
 */
class Aws extends ServiceBuilderLoader
{
    /**
     * @var string Current version of the SDK
     */
    const VERSION = '2.3.4';

    /**
     * Create a new service locator for the AWS SDK
     *
     * You can configure the service locator is four different ways:
     *
     * 1. Use the default configuration file shipped with the SDK that wires
     *   class names with service short names and specify global parameters to
     *   add to every definition (e.g. key, secret, credentials, etc)
     *
     * 2. Use a custom configuration file that extends the default config and
     *   supplies credentials for each service.
     *
     * 3. Use a custom config file that wires services to custom short names for
     *    services.
     *
     * 4. If you are on Amazon EC2, you can use the default configuration file
     *    and not provide any credentials so that you are using InstanceProfile
     *    credentials.
     *
     * @param array|string|\SimpleXMLElement $config           An instantiated SimpleXMLElement containing configuration
     *                                                         data, the full path to an .xml or .js|.json file, or when
     *                                                         using the default configuration file, an associative
     *                                                         array of data to use as global parameters to pass to each
     *                                                         service as it is instantiated.
     * @param array                          $globalParameters Array of global parameters to pass to every service as it
     *                                                         is instantiated.
     *
     * @return ServiceBuilder
     */
    public static function factory($config = null, array $globalParameters = array())
    {
        if (!$config) {
            // If nothing is passed in, then use the default configuration file
            // with Instance profile credentials
            $config = self::getDefaultServiceDefinition();
        } elseif (is_array($config)) {
            // If an array was passed, then use the default configuration file
            // with global parameter overrides in the first argument
            $globalParameters = $config;
            $config = self::getDefaultServiceDefinition();
        }

        $loader = new static();

        return $loader->load($config, $globalParameters);
    }

    /**
     * Get the full path to the default JSON service definition file
     *
     * @return string
     */
    public static function getDefaultServiceDefinition()
    {
        return __DIR__  . '/Resources/aws-config.php';
    }

    /**
     * Constructor
     */
    public function __construct()
    {
        $this->addAlias('_aws', self::getDefaultServiceDefinition())
            ->addAlias('_sdk1', __DIR__  . '/Resources/sdk1-config.php');
    }
}