<?php

/**
 * Copyright 2019 Huawei Technologies Co.,Ltd.
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
 * this file except in compliance with the License.  You may obtain a copy of the
 * License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software distributed
 * under the License 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 Obs\Internal\Common;

use Obs\ObsClient;

class ObsTransform implements ITransform {
    private static $instance;
    
    private function __construct(){}
    
    public static function getInstance() {
        if (!(self::$instance instanceof ObsTransform)) {
            self::$instance = new ObsTransform();
        }
        return self::$instance;
    }
     
    
    public function transform($sign, $para) {
        if ($sign === 'aclHeader') {
            $para = $this->transAclHeader($para);
        } else if ($sign === 'aclUri') {
            $para = $this->transAclGroupUri($para);
        } else if ($sign == 'event') {
            $para = $this->transNotificationEvent($para);
        } else if ($sign == 'storageClass') {
            $para = $this->transStorageClass($para);
        }
        return $para;
    }
    
    private function transAclHeader($para) {
        if ($para === ObsClient::AclAuthenticatedRead || $para === ObsClient::AclBucketOwnerRead || 
                $para === ObsClient::AclBucketOwnerFullControl || $para === ObsClient::AclLogDeliveryWrite) {
            $para = null;
        }
        return $para;
    }
    
    private function transAclGroupUri($para) {
        if ($para === ObsClient::GroupAllUsers) {
            $para = ObsClient::AllUsers;
        }
        return $para;
    }
    
    private function transNotificationEvent($para) {
        $pos = strpos($para, 's3:');
        if ($pos !== false && $pos === 0) {
            $para = substr($para, 3);
        }
        return $para;
    }
    
    private function transStorageClass($para) {
        $search = array('STANDARD', 'STANDARD_IA', 'GLACIER');
        $repalce = array(ObsClient::StorageClassStandard, ObsClient::StorageClassWarm, ObsClient::StorageClassCold);
        $para = str_replace($search, $repalce, $para);
        return $para;
    }
}