<?php

if (!defined('ABSPATH')) exit;
if (!defined('UPDRAFTPLUS_DIR')) die('No direct access allowed');

// Converted to multi-options (Feb 2017-) and previous options conversion removed: Yes

/**
 * This class is used by both UpdraftPlus_S3 and UpdraftPlus_S3_Compat
 */
class UpdraftPlus_S3Exception extends Exception {
	public function __construct($message, $file, $line, $code = 0) {
		parent::__construct($message, $code);
		$this->file = $file;
		$this->line = $line;
	}
}

if (!class_exists('UpdraftPlus_BackupModule')) updraft_try_include_file('methods/backup-module.php', 'require_once');

class UpdraftPlus_BackupModule_s3 extends UpdraftPlus_BackupModule {

	// This variable can/should be over-ridden in child classes as appropriate
	protected $use_v4 = true;
	
	// This variable can/should be over-ridden in child classes as appropriate
	protected $provider_can_use_aws_sdk = true;

	// This variable can/should be over-ridden in child classes as appropriate
	protected $provider_has_regions = true;

	protected $quota_used = null;

	protected $s3_exception;

	protected $download_chunk_size = 10485760;

	protected $current_upload_entity = 'files';

	private $got_with;

	/**
	 * Retrieve specific options for this remote storage module
	 *
	 * @param Boolean $force_refresh - if set, and if relevant, don't use cached credentials, but get them afresh
	 *
	 * @return Array - an array of options
	 */
	protected function get_config($force_refresh = false) {// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- $force_refresh unused
		$opts = $this->get_options();
		$opts['whoweare'] = 'S3';
		$opts['whoweare_long'] = 'Amazon S3';
		$opts['key'] = 's3';
		return $opts;
	}

	/**
	 * This method overrides the parent method and lists the supported features of this remote storage option.
	 *
	 * @return Array - an array of supported features (any features not mentioned are asuumed to not be supported)
	 */
	public function get_supported_features() {
		// This options format is handled via only accessing options via $this->get_options()
		return array('multi_options', 'config_templates', 'multi_storage', 'conditional_logic');
	}

	/**
	 * Retrieve default options for this remote storage module.
	 *
	 * @return Array - an array of options
	 */
	public function get_default_options() {
		return array(
			'accesskey' => '',
			'secretkey' => '',
			'path' => '',
			'rrs' => '',
			'server_side_encryption' => '',
		);
	}

	/**
	 * Return the name of the class that should be used to interface with the storage provider, and make sure that it has been include()-ed.
	 *
	 * @return String - e.g. UpdraftPlus_S3, UpdraftPlus_S3_Compat
	 */
	protected function indicate_s3_class() {
	
		// N.B. : The classes must have different names, as if multiple remote storage options are chosen, then we could theoretically need both (if both Amazon and a compatible-S3 provider are used)

		// UpdraftPlus_S3 (the internal, non-AWS toolkit) is used when not accessing Amazon Web Services, so set that as the default
		$class_to_use = 'UpdraftPlus_S3';
		
		// If on a PHP version supported by the AWS SDK, and if the constant forcing the internal toolkit is not set, then consider using it. The 3.x branch of the AWS SDK requires PHP 5.5+
		// The "old" in the define is a legacy reference to a time before v4 signatures were in that library.
		if (version_compare(PHP_VERSION, '5.5', '>=') && $this->provider_can_use_aws_sdk && (!defined('UPDRAFTPLUS_S3_OLDLIB') || !UPDRAFTPLUS_S3_OLDLIB)) {
			
			// Switch to AWS SDK increasingly less over time
			if (!function_exists('curl_init') || (defined('UPDRAFTPLUS_FORCE_S3_AWS_SDK') && UPDRAFTPLUS_FORCE_S3_AWS_SDK) || apply_filters('updraftplus_indicate_s3_class_prefer_aws_sdk', false)) {
				$class_to_use = 'UpdraftPlus_S3_Compat';
			}
		}

		if (!class_exists($class_to_use)) {
			if ('UpdraftPlus_S3_Compat' == $class_to_use) {
				updraft_try_include_file('includes/S3compat.php', 'include_once');
			} else {
				updraft_try_include_file('includes/S3.php', 'include_once');
			}
		}
		
		return $class_to_use;
	}

	/**
	 * Get an S3 object, after setting our options. Public because called externally from UpdraftPlus_Addon_S3_Enhanced
	 *
	 * @param  String	   $key 		   S3 Key
	 * @param  String	   $secret 		   S3 secret
	 * @param  Boolean	   $useservercerts User server certificates
	 * @param  Boolean	   $disableverify  Check if disableverify is enabled
	 * @param  Boolean	   $nossl 		   Check if there is SSL or not
	 * @param  Null|String $endpoint 	   S3 endpoint to use
	 * @param  Boolean	   $sse 		   A flag to use server side encryption
	 * @param  String	   $session_token  The session token returned by AWS for temporary credentials access
	 *
	 * @return Object|WP_Error
	 */
	public function getS3($key, $secret, $useservercerts, $disableverify, $nossl, $endpoint = null, $sse = false, $session_token = null) {
		
		$storage = $this->get_storage();
		if (!empty($storage) && !is_wp_error($storage)) return $storage;

		if (is_string($key)) $key = trim($key);
		if (is_string($secret)) $secret = trim($secret);

		// Ignore the 'nossl' setting if the endpoint is DigitalOcean Spaces (https://developers.digitalocean.com/documentation/v2/)
		if (is_string($endpoint) && preg_match('/\.digitaloceanspaces\.com$/i', $endpoint)) {
			$nossl = apply_filters('updraftplus_gets3_nossl', false, $endpoint, $nossl);
		}
		
		// Saved in case the object needs recreating for the corner-case where there is no permission to look up the bucket location
		$this->got_with = array(
			'key' => $key,
			'secret' => $secret,
			'useservercerts' => $useservercerts,
			'disableverify' => $disableverify,
			'nossl' => $nossl,
			'server_side_encryption' => $sse,
			'session_token' => $session_token
		);

		if (is_wp_error($key)) return $key;

		if ('' == $key || '' == $secret) {
			return new WP_Error('no_settings', get_class($this).': '.__('No settings were found - please go to the Settings tab and check your settings', 'updraftplus'));
		}

		$use_s3_class = $this->indicate_s3_class();

		if (!class_exists('WP_HTTP_Proxy')) include_once(ABSPATH.WPINC.'/class-http.php');
		$proxy = new WP_HTTP_Proxy();

		$use_ssl = true;
		$ssl_ca = false;

		try {
			$storage = new $use_s3_class($key, $secret, $use_ssl, $ssl_ca, $endpoint, $session_token);

			// Comment before 1.22.10 - "the use of calling use_dns_bucket_name method here is to switch the storage from using path-style to dns style." But at this stage, we don't have a bucket name, so this shouldn't be here.
			// $this->maybe_use_dns_bucket_name($storage, ...);
			$signature_version = empty($this->use_v4) ? 'v2' : 'v4';
			$signature_version = apply_filters('updraftplus_s3_signature_version', $signature_version, $this->use_v4, $this);
			if (!is_a($storage, 'UpdraftPlus_S3_Compat')) {
				$storage->setSignatureVersion($signature_version);
			}
		} catch (Exception $e) {
		
			// Catch a specific PHP engine bug - see HS#6364
			if ('UpdraftPlus_S3_Compat' == $use_s3_class && is_a($e, 'InvalidArgumentException') && false !== strpos('Invalid signature type: s3', $e->getMessage())) {
				updraft_try_include_file('includes/S3.php', 'include_once');
				$use_s3_class = 'UpdraftPlus_S3';
				$try_again = true;
			} else {
				$this->log(__('Error: Failed to initialise', 'updraftplus').": ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
				$this->log(__('Error: Failed to initialise', 'updraftplus'));
				/* translators: %s: Service name */
				return new WP_Error('s3_init_failed', sprintf(__('%s Error: Failed to initialise', 'updraftplus'), 'S3').": ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
			}
		}
		
		if (!empty($try_again)) {
			try {
				$storage = new $use_s3_class($key, $secret, $use_ssl, $ssl_ca, $endpoint, $session_token);
				// Comment before 1.22.10 - "the use of calling use_dns_bucket_name method here is to switch the storage from using path-style to dns style." But at this stage, we don't have a bucket name, so this shouldn't be here.
				// $this->maybe_use_dns_bucket_name($storage, ...);
			} catch (Exception $e) {
				$this->log(__('Error: Failed to initialise', 'updraftplus').": ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
				$this->log(__('Error: Failed to initialise', 'updraftplus'));
				/* translators: %s: Service name */
				return new WP_Error('s3_init_failed', sprintf(__('%s Error: Failed to initialise', 'updraftplus'), 'S3').": ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
			}
			$this->log("Hit a PHP engine bug - had to switch to the internal S3 library");
		}

		if ($proxy->is_enabled()) {
			// WP_HTTP_Proxy returns empty strings where we want nulls
			$user = $proxy->username();
			if (empty($user)) {
				$user = null;
				$pass = null;
			} else {
				$pass = $proxy->password();
				if (empty($pass)) $pass = null;
			}
			$port = (int) $proxy->port();
			if (empty($port)) $port = 8080;
			$storage->setProxy($proxy->host(), $user, $pass, CURLPROXY_HTTP, $port);
		}
		
		if ($this->use_sse() || $sse) $storage->setServerSideEncryption('AES256');

		$this->set_storage($storage);

		return $storage;
	}

	/**
	 * Given an S3 object, possibly set the region on it
	 *
	 * @param Object $obj		  - like UpdraftPlus_S3
	 * @param String $region
	 * @param String $bucket_name
	 */
	protected function set_region($obj, $region, $bucket_name = '') {// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- $bucket_name

	// AWS Regions: https://docs.aws.amazon.com/general/latest/gr/rande.html
	// https://docs.aws.amazon.com/general/latest/gr/s3.html#auto-endpoints-s3
		switch ($region) {
			case 'EU':
			case 'eu-west-1':
			$endpoint = 's3-eu-west-1.amazonaws.com';
				break;
			case 'us-east-1':
			$endpoint = 's3.amazonaws.com';
				break;
			case 'us-west-1':
			case 'us-east-2':
			case 'us-west-2':
			$endpoint = 's3-'.$region.'.amazonaws.com';
				break;
			case 'sa-east-1':
			case 'us-gov-west-1':
			case 'ca-central-1':
			case 'ap-northeast-1':
			case 'ap-northeast-2':
			case 'ap-southeast-1':
			case 'ap-southeast-2':
			case 'eu-central-1':
			case 'eu-south-1':
			case 'eu-north-1':
			case 'eu-west-2':
			case 'eu-west-3':
			case 'ap-south-1':
			case 'me-south-1':
			case 'af-south-1':
			case 'ap-east-1':
			case 'ap-northeast-3':
			case 'ap-south-2':
			case 'ap-southeast-3':
			case 'ap-southeast-5':
			case 'ap-southeast-4':
			case 'ap-southeast-7':
			case 'ca-west-1':
			case 'eu-south-2':
			case 'eu-central-2':
			case 'il-central-1':
			case 'me-central-1':
			case 'us-gov-east-1':
			case 'mx-central-1':
			case 'ap-southeast-6':
			case 'ap-east-2':
			$endpoint = 's3.'.$region.'.amazonaws.com';
				break;
			case 'cn-north-1':
			case 'cn-northwest-1':
			$endpoint = 's3.'.$region.'.amazonaws.com.cn';
				break;
			default:
				break;
		}
		
		if (isset($endpoint)) {
			$this->log("Set region (".get_class($obj)."): $region");
			$obj->setRegion($region);

			if (!is_a($obj, 'UpdraftPlus_S3_Compat')) {
				$this->log("Set endpoint: $endpoint");
				$obj->setEndpoint($endpoint);
			}
		}
	}

	/**
	 * Whether to always use server-side encryption.
	 *
	 * This can be over-ridden in child classes of course... and the method here is both the default and the value used for AWS
	 *
	 * @return Boolean
	 */
	protected function use_sse() {
		return false;
	}
	
	/**
	 * Perform the upload of backup archives
	 *
	 * @param Array $backup_array - a list of file names (basenames) (within UD's directory) to be uploaded
	 *
	 * @return Mixed - return (boolean)false to indicate failure, or anything else to have it passed back at the delete stage (most useful for a storage object).
	 */
	public function backup($backup_array) {

		global $updraftplus;

		$config = $this->get_config();

		if (empty($config['accesskey']) && !empty($config['error_message'])) {
			$err = new WP_Error('no_settings', $config['error_message']);
			return $updraftplus->log_wp_error($err, false, true);
		}

		if (empty($config['sessiontoken'])) $config['sessiontoken'] = null;
		
		$storage = $this->getS3(
			$config['accesskey'],
			$config['secretkey'],
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_useservercerts'),
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_disableverify'),
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_nossl'),
			null,
			!empty($config['server_side_encryption']),
			$config['sessiontoken']
		);

		if (is_wp_error($storage)) return $updraftplus->log_wp_error($storage, false, true);

		$whoweare = $config['whoweare'];
		$whoweare_key = $config['key'];
		$whoweare_keys = substr($whoweare_key, 0, 3);
		
		if (is_a($storage, 'UpdraftPlus_S3_Compat') && !class_exists('XMLWriter')) {
			$this->log('The required XMLWriter PHP module is not installed');
			/* translators: %s: Required PHP module name */
			$this->log(sprintf(__('The required %s PHP module is not installed - ask your web hosting company to enable it', 'updraftplus'), 'XMLWriter'), 'error');
			return false;
		}

		$bucket_name = untrailingslashit($config['path']);
		$bucket_path = "";
		$orig_bucket_name = $bucket_name;

		if (preg_match("#^([^/]+)/(.*)$#", $bucket_name, $bmatches)) {
			$bucket_name = $bmatches[1];
			$bucket_path = $bmatches[2]."/";
		}

		list($storage, $config, $bucket_exists, $region) = $this->get_bucket_access($storage, $config, $bucket_name, $bucket_path);

		// See if we can detect the region (which implies the bucket exists and is ours), or if not create it
		if ($bucket_exists) {

			$updraft_dir = trailingslashit($updraftplus->backups_dir_location());

			foreach ($backup_array as $key => $file) {
				if ('db' != substr($key, 0, 2)) {
					$this->current_upload_entity = 'files';
				} else {
					$this->current_upload_entity = 'databases';
				}

				// We upload in 5MB chunks to allow more efficient resuming and hence uploading of larger files
				// N.B.: 5MB is Amazon's minimum. So don't go lower or you'll break it.
				$fullpath = $updraft_dir.$file;
				$orig_file_size = filesize($fullpath);
				
				if (!file_exists($fullpath)) {
					$this->log("File not found: $file: $whoweare: ");
					$this->log("$file: ".
						sprintf(
							/* translators: %s: Error message */
							__('Error: %s', 'updraftplus'),
							__('File not found', 'updraftplus')
						),
					'error');
					continue;
				}

				if (isset($config['quota']) && method_exists($this, 's3_get_quota_info')) {
					$quota_used = $this->s3_get_quota_info('numeric', $config['quota']);
					if (false === $quota_used) {
						$this->log("Quota usage: count failed");
					} else {
						$this->quota_used = $quota_used;
						if ($config['quota'] - $this->quota_used < $orig_file_size) {
							if (method_exists($this, 's3_out_of_quota')) call_user_func(array($this, 's3_out_of_quota'), $config['quota'], $this->quota_used, $orig_file_size);
							continue;
						} else {
							$quota_transient_used = $this->quota_transient_used ? ' (via transient)' : '';
							// We don't need to log this always - the s3_out_of_quota method will do its own logging
							$this->log("Quota is available: used=$quota_used (".round($quota_used/1048576, 1)." MB), total=".$config['quota']." (".round($config['quota']/1048576, 1)." MB), needed=$orig_file_size (".round($orig_file_size/1048576, 1)." MB)".$quota_transient_used);
						}
					}
				}

				$chunks = floor($orig_file_size / 5242880);
				// There will be a remnant unless the file size was exactly on a 5MB boundary
				if ($orig_file_size % 5242880 > 0) $chunks++;
				$hash = md5($file);

				$extra = $this->provider_has_regions ? " ($region)" : '';
				
				$this->log("upload{$extra}: $file (chunks: $chunks) -> $whoweare_key://$bucket_name/$bucket_path$file");

				$filepath = $bucket_path.$file;

				// This is extra code for the 1-chunk case, but less overhead (no bothering with job data)
				if ($chunks < 2) {
					$storage->setExceptions(true);
					try {
						if (!$storage->putObjectFile($fullpath, $bucket_name, $filepath, 'private', array(), array(), apply_filters('updraft_'.$whoweare_key.'_storageclass', 'STANDARD', $storage, $config))) {
							$this->log("regular upload: failed ($fullpath)");
							/* translators: %s: Service name */
							$this->log("$file: ".sprintf(__('%s Error: Failed to upload', 'updraftplus'), $whoweare), 'error');
						} else {
							$this->quota_used += $orig_file_size;
							if (method_exists($this, 's3_record_quota_info')) $this->s3_record_quota_info($this->quota_used, $config['quota']);
							$extra_log = '';
							if (method_exists($this, 's3_get_quota_info')) {
								$extra_log = ', quota used now: '.round($this->quota_used / 1048576, 1).' MB';
							}
							$this->log("regular upload: success$extra_log");
							$updraftplus->uploaded_file($file);
						}
					} catch (Exception $e) {
						/* translators: %s: Service name */
						$this->log("$file: ".sprintf(__('%s Error: Failed to upload', 'updraftplus'), $whoweare).": ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile());
						/* translators: %s: Service name */
						$this->log("$file: ".sprintf(__('%s Error: Failed to upload', 'updraftplus'), $whoweare), 'error');
					}
					$storage->setExceptions(false);
				} else {

					// Retrieve the upload ID
					$upload_id = $this->jobdata_get($hash.'_uid', null, "upd_{$whoweare_keys}_{$hash}_uid");
					if (empty($upload_id)) {
						$storage->setExceptions(true);
						try {
							$upload_id = $storage->initiateMultipartUpload($bucket_name, $filepath, 'private', array(), array(), apply_filters('updraft_'.$whoweare_key.'_storageclass', 'STANDARD', $storage, $config));
						} catch (Exception $e) {
						
							$this->log("exception (".get_class($e).") whilst trying initiateMultipartUpload: ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
							
							if (false !== strpos($e->getMessage(), '[ExpiredToken]')) {
								$this->log("Re-scheduling resumption and aborting so that new token can be requested upon resumption");
								UpdraftPlus_Job_Scheduler::reschedule(50);
								UpdraftPlus_Job_Scheduler::record_still_alive();
								die;
							}
							
							$upload_id = false;
							
						}
						$storage->setExceptions(false);

						if (empty($upload_id)) {
							$this->log("upload: failed: could not get uploadId for multipart upload ($filepath)");
							/* translators: %s: Service name */
							$this->log(sprintf(__("%s upload: getting uploadID for multipart upload failed - see log file for more details", 'updraftplus'), $whoweare), 'error');
							continue;
						} else {
							$this->log("chunked upload: got multipart ID: $upload_id");
							$this->jobdata_set($hash.'_uid', $upload_id);
						}
					} else {
						$this->log("chunked upload: retrieved previously obtained multipart ID: $upload_id");
					}

					$successes = 0;
					$etags = array();
					for ($i = 1; $i <= $chunks; $i++) {
						$etag = $this->jobdata_get($hash.'_etag_'.$i, null, "ud_{$whoweare_keys}_{$hash}_e$i");
						if (null !== $etag && strlen($etag) > 0) {
							$this->log("chunk $i: was already completed (etag: $etag)");
							$successes++;
							array_push($etags, $etag);
						} else {
							// Sanity check: we've seen a case where an overlap was truncating the file from underneath us
							if (filesize($fullpath) < $orig_file_size) {
								$this->log("error: $key: chunk $i: file was truncated underneath us (orig_size=$orig_file_size, now_size=".filesize($fullpath).")");
								/* translators: %s: File path */
								$this->log(sprintf(__('error: file %s was shortened unexpectedly', 'updraftplus'), $fullpath), 'error');
							}
							
							$storage->setExceptions(true);
							try {
								$etag = $storage->uploadPart($bucket_name, $filepath, $upload_id, $fullpath, $i);
							} catch (Exception $e) {
								
								$this->log("exception (".get_class($e).") during uploadPart: ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
								
								if (false !== strpos($e->getMessage(), '[ExpiredToken]')) {
									$this->log("Re-scheduling resumption and aborting so that new token can be requested upon resumption");
									UpdraftPlus_Job_Scheduler::reschedule(50);
									UpdraftPlus_Job_Scheduler::record_still_alive();
									die;
								}
								
								$etag = false;
							}
							$storage->setExceptions(false);
							
							if (false !== $etag && is_string($etag)) {
								$updraftplus->record_uploaded_chunk(round(100*$i/$chunks, 1), "$i, $etag", $fullpath);
								array_push($etags, $etag);
								$this->jobdata_set($hash.'_etag_'.$i, $etag);
								$successes++;
							} else {
								$this->log("chunk $i: upload failed");
								/* translators: %s: Chunk number */
								$this->log(sprintf(__("chunk %s: upload failed", 'updraftplus'), $i), 'error');
							}
						}
					}
					if ($successes >= $chunks) {
						$this->log("upload: all chunks uploaded; will now instruct $whoweare to re-assemble");

						$storage->setExceptions(true);
						try {
							if ($storage->completeMultipartUpload($bucket_name, $filepath, $upload_id, $etags)) {
								$this->log("upload ($key): re-assembly succeeded");
								$updraftplus->uploaded_file($file);
								$this->quota_used += $orig_file_size;
								if (method_exists($this, 's3_record_quota_info')) $this->s3_record_quota_info($this->quota_used, $config['quota']);
							} else {
								$this->log("upload ($key): re-assembly failed ($file)");
								/* translators: %s: Upload key */
								$this->log(sprintf(__('upload (%s): re-assembly failed (see log for more details)', 'updraftplus'), $key), 'error');
							}
						} catch (Exception $e) {
							$this->log("re-assembly error ($key): ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
							/* translators: 1: Service name, 2: Error message */
							$this->log($e->getMessage().": ".sprintf(__('%1$s re-assembly error (%2$s): (see log file for more)', 'updraftplus'), $whoweare, $e->getMessage()), 'error');
						}
						// Remember to unset, as the deletion code later reuses the object
						$storage->setExceptions(false);
					} else {
						$this->log("upload: upload was not completely successful on this run");
					}
				}
			}
			
			// Allows counting of the final quota accurately
			if (method_exists($this, 's3_prune_retained_backups_finished')) {
				add_action('updraftplus_prune_retained_backups_finished', array($this, 's3_prune_retained_backups_finished'));
			}
			
			return array('storage' => $storage, 's3_orig_bucket_name' => $orig_bucket_name);
		} else {
		
			$extra_text = empty($this->s3_exception) ? '' : ' '.$this->s3_exception->getMessage().' (line: '.$this->s3_exception->getLine().', file: '.$this->s3_exception->getFile().')';
			$extra_text_short = empty($this->s3_exception) ? '' : ' '.$this->s3_exception->getMessage();
		
			$this->log("Error: Failed to access bucket $bucket_name.".$extra_text);
			$this->log(
				/* translators: %s: Bucket name */
				sprintf(__('Error: Failed to access bucket %s.', 'updraftplus'), $bucket_name).' '.
				__('Check your permissions and credentials.', 'updraftplus').' (1)'.$extra_text_short,
			'error');
		}
	}
	
	/**
	 * This function lists the files found in the configured storage location
	 *
	 * @param  String $match - a substring to require (tested via strpos() !== false)
	 *
	 * @return Array - each file is represented by an array with entries 'name' and (optional) 'size'
	 */
	public function listfiles($match = 'backup_') {
		$config = $this->get_config();
		return $this->listfiles_with_path($config['path'], $match);
	}
	
	protected function possibly_wait_for_bucket_or_user($config, $storage) {

		$bucket_name = untrailingslashit($config['path']);

		if (preg_match("#^([^/]+)/(.*)$#", $bucket_name, $bmatches)) {
			$bucket_name = $bmatches[1];
		}

		if (!empty($config['is_new_bucket'])) {
			if (method_exists($storage, 'waitForBucket')) {
				$storage->setExceptions(true);
				try {
					$storage->waitForBucket($bucket_name);
				} catch (Exception $e) {
					// This seems to often happen - we get a 403 on a newly created user/bucket pair, even though the bucket was already waited for by the creator
					// We could just sleep() - a sleep(5) seems to do it. However, given that it's a new bucket, that's unnecessary.
					$storage->setExceptions(false);
					return array();
				}
				$storage->setExceptions(false);
			} else {
				sleep(4);
			}
		} elseif (!empty($config['is_new_user'])) {
			// A crude waiter, because the AWS toolkit does not have one for IAM propagation - basically, loop around a few times whilst the access attempt still fails
			$attempt_flag = 0;
			while ($attempt_flag < 5) {

				$attempt_flag++;
				if (@$storage->getBucketLocation($bucket_name)) {// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- Silenced to suppress errors that may arise because of the method.
					$attempt_flag = 100;
				} else {
					if (empty($config['sessiontoken'])) $config['sessiontoken'] = null;
					sleep($attempt_flag*1.5 + 1);

					$sse = !empty($config['server_side_encryption']);
					
					// Get the bucket object again... because, for some reason, the AWS PHP SDK (at least on the current version we're using, March 2016) calculates an incorrect signature on subsequent attempts
					$this->set_storage(null);

					$storage = $this->getS3(
						$config['accesskey'],
						$config['secretkey'],
						UpdraftPlus_Options::get_updraft_option('updraft_ssl_useservercerts'),
						UpdraftPlus_Options::get_updraft_option('updraft_ssl_disableverify'),
						UpdraftPlus_Options::get_updraft_option('updraft_ssl_nossl'),
						null,
						$sse,
						$config['sessiontoken']
					);

					if (is_wp_error($storage)) return $storage;
					if (!is_a($storage, 'UpdraftPlus_S3') && !is_a($storage, 'UpdraftPlus_S3_Compat')) return new WP_Error('no_s3object', 'Failed to gain access to '.$config['whoweare']);
					
				}
			}
		}
		
		return $storage;
	}
	
	/**
	 * The purpose of splitting this into a separate method, is to also allow listing with a different path
	 *
	 * @param  String  $path 			   Path to check
	 * @param  String  $match 			   The match for idetifying the bucket name
	 * @param  Boolean $include_subfolders Check if list file need to include sub folders
	 * @return Array
	 */
	public function listfiles_with_path($path, $match = 'backup_', $include_subfolders = false) {
		
		$bucket_name = untrailingslashit($path);
		$bucket_path = '';

		if (preg_match("#^([^/]+)/(.*)$#", $bucket_name, $bmatches)) {
			$bucket_name = $bmatches[1];
			$bucket_path = trailingslashit($bmatches[2]);
		}

		$config = $this->get_config();
		
		$sse = empty($config['server_side_encryption']) ? false : true;
		if (empty($config['sessiontoken'])) $config['sessiontoken'] = null;
		
		$storage = $this->getS3(
			$config['accesskey'],
			$config['secretkey'],
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_useservercerts'),
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_disableverify'),
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_nossl'),
			null,
			$sse,
			$config['sessiontoken']
		);

		if (is_wp_error($storage)) return $storage;
		if (!is_a($storage, 'UpdraftPlus_S3') && !is_a($storage, 'UpdraftPlus_S3_Compat')) return new WP_Error('no_s3object', 'Failed to gain access to '.$config['whoweare']);
		
		$storage = $this->possibly_wait_for_bucket_or_user($config, $storage);
		if (!is_a($storage, 'UpdraftPlus_S3') && !is_a($storage, 'UpdraftPlus_S3_Compat')) return $storage;
		
		list($storage, $config, $bucket_exists, $region) = $this->get_bucket_access($storage, $config, $bucket_name, $bucket_path);// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- The value is passed back from get_bucket_access

		$bucket = $storage->getBucket($bucket_name, $bucket_path.$match);

		if (!is_array($bucket)) return array();

		$results = array();

		foreach ($bucket as $key => $object) {
			if (!is_array($object) || empty($object['name'])) continue;
			if (isset($object['size']) && 0 == $object['size']) continue;

			if ($bucket_path) {
				if (0 !== strpos($object['name'], $bucket_path)) continue;
				$object['name'] = substr($object['name'], strlen($bucket_path));
			} else {
				if (!$include_subfolders && false !== strpos($object['name'], '/')) continue;
			}

			$result = array('name' => $object['name']);
			if (isset($object['size'])) $result['size'] = (int) $object['size'];
			unset($bucket[$key]);
			$results[] = $result;
		}

		return $results;

	}
	
	/**
	 * Delete a single file from the service using S3
	 *
	 * @param Array|String $files    - array of file names to delete
	 * @param Array        $s3arr    - s3 service object and container details
	 * @param Array        $sizeinfo - size of files to delete, used for quota calculation
	 * @return Boolean|String - either a boolean true or an error code string
	 */
	public function delete($files, $s3arr = false, $sizeinfo = array()) {

		global $updraftplus;
		if (is_string($files)) $files = array($files);

		$config = $this->get_config();
		$sse = empty($config['server_side_encryption']) ? false : true;
		if (empty($config['sessiontoken'])) $config['sessiontoken'] = null;

		if ($s3arr) {
			$storage = $s3arr['storage'];
			$orig_bucket_name = $s3arr['s3_orig_bucket_name'];
		} else {
			$storage = $this->getS3(
				$config['accesskey'],
				$config['secretkey'],
				UpdraftPlus_Options::get_updraft_option('updraft_ssl_useservercerts'),
				UpdraftPlus_Options::get_updraft_option('updraft_ssl_disableverify'),
				UpdraftPlus_Options::get_updraft_option('updraft_ssl_nossl'),
				null,
				$sse,
				$config['sessiontoken']
			);

			if (is_wp_error($storage)) return $updraftplus->log_wp_error($storage, false, false);

			$bucket_name = untrailingslashit($config['path']);
			$orig_bucket_name = $bucket_name;

			if (preg_match("#^([^/]+)/(.*)$#", $bucket_name, $bmatches)) {
				$bucket_name = $bmatches[1];
				$bucket_path = $bmatches[2]."/";
			} else {
				$bucket_path = '';
			}
			
			list($storage, $config, $bucket_exists, $region) = $this->get_bucket_access($storage, $config, $bucket_name, $bucket_path);// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- The value is passed back from get_bucket_access

			if (!$bucket_exists) {
				$this->log("Error: Failed to access bucket $bucket_name. Check your permissions and credentials.");
				$this->log(
					/* translators: %s: Bucket name */
					sprintf(__('Error: Failed to access bucket %s.', 'updraftplus'), $bucket_name).' '.
					__('Check your permissions and credentials.', 'updraftplus'),
				'error');
				return 'container_access_error';
			}
		}

		$ret = true;

		foreach ($files as $i => $file) {

			if (preg_match("#^([^/]+)/(.*)$#", $orig_bucket_name, $bmatches)) {
				$s3_bucket=$bmatches[1];
				$s3_uri = $bmatches[2]."/".$file;
			} else {
				$s3_bucket = $orig_bucket_name;
				$s3_uri = $file;
			}
			$this->log("Delete remote: bucket=$s3_bucket, URI=$s3_uri");

			$storage->setExceptions(true);
			try {
				if (!$storage->deleteObject($s3_bucket, $s3_uri)) {
					$this->log("Delete failed");
				} elseif (null !== $this->quota_used && !empty($sizeinfo[$i]) && isset($config['quota']) && method_exists($this, 's3_record_quota_info')) {
					$this->quota_used -= $sizeinfo[$i];
					$this->s3_record_quota_info($this->quota_used, $config['quota']);
				}
			} catch (Exception $e) {
				$this->log("delete failed (".get_class($e)."): ".$e->getMessage().' (line: '.$e->getLine().', file: '.$e->getFile().')');
				$storage->setExceptions(false);
				$ret = 'file_delete_error';
			}
			$storage->setExceptions(false);

		}

		return $ret;

	}

	/**
	 * Download a file from the remote storage
	 *
	 * @param string $file The specific file to be downloaded
	 * @return void
	 */
	public function download($file) {

		global $updraftplus;

		$config = $this->get_config();
		$sse = empty($config['server_side_encryption']) ? false : true;
		if (empty($config['sessiontoken'])) $config['sessiontoken'] = null;
		
		$storage = $this->getS3(
			$config['accesskey'],
			$config['secretkey'],
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_useservercerts'),
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_disableverify'),
			UpdraftPlus_Options::get_updraft_option('updraft_ssl_nossl'),
			null,
			$sse,
			$config['sessiontoken']
		);
		if (is_wp_error($storage)) return $updraftplus->log_wp_error($storage, false, true);

		$bucket_name = untrailingslashit($config['path']);
		$bucket_path = "";

		if (preg_match("#^([^/]+)/(.*)$#", $bucket_name, $bmatches)) {
			$bucket_name = $bmatches[1];
			$bucket_path = $bmatches[2]."/";
		}
		
		list($storage, $config, $bucket_exists, $region) = $this->get_bucket_access($storage, $config, $bucket_name, $bucket_path);// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- The value is passed back from get_bucket_access

		if ($bucket_exists) {

			$file_info = $this->listfiles($file);
			
			if (is_array($file_info)) {
				foreach ($file_info as $finfo) {
					if ($finfo['name'] == $file) {
						$file_size = $finfo['size'];
						break;
					}
				}
			}
			
			if (!isset($file_size)) {
				$this->log("Error: Failed to download $file. Check your permissions and credentials. Retrieved data: ".serialize($file_info));
				$this->log(
					/* translators: %s: File name */
					sprintf(__('Error: Failed to download %s.', 'updraftplus'), $file).' '.
					__('Check your permissions and credentials.', 'updraftplus'),
				'error');
				return false;
			}
			
			return $updraftplus->chunked_download($file, $this, $file_size, true, $storage, $this->download_chunk_size);
			
			/*
			// The code before we switched to chunked downloads. Unfortunately the version of the AWS SDK we have to use for PHP 5.3 compatibility doesn't have callbacks, which makes it possible for multiple downloaders to start at once and over-write each-other.
			$whoweare = $config['whoweare'];
			$fullpath = $updraftplus->backups_dir_location().'/'.$file;
			if (!$storage->getObject($bucket_name, $bucket_path.$file, $fullpath, true)) {
				$updraftplus->log("$whoweare Error: Failed to download $file. Check your permissions and credentials.");
				$updraftplus->log(sprintf(__('%s Error: Failed to download %s.', 'updraftplus'),$whoweare, $file).' '.__('
Check your permissions and credentials.','updraftplus'), 'error');
				return false;
			}
			*/
			
		} else {
			$this->log("Error: Failed to access bucket $bucket_name. Check your permissions and credentials.");
			$this->log(
				/* translators: %s: Bucket name */
				sprintf(__('Error: Failed to access bucket %s.', 'updraftplus'), $bucket_name).' '.
				__('Check your permissions and credentials.', 'updraftplus'),
			'error');
			return false;
		}
		return true;

	}
	
	public function chunked_download($file, $headers, $storage, $fh) {

		$resume = false;
		$config = $this->get_config();
		$bucket_name = untrailingslashit($config['path']);
		$bucket_path = "";

		if (preg_match("#^([^/]+)/(.*)$#", $bucket_name, $bmatches)) {
			$bucket_name = $bmatches[1];
			$bucket_path = $bmatches[2]."/";
		}
	
		if (is_array($headers) && !empty($headers['Range']) && preg_match('/bytes=(\d+)-(\d+)$/', $headers['Range'], $matches)) {
			$resume = $headers['Range'];
		}
		
		if (!$storage->getObject($bucket_name, $bucket_path.$file, $fh, $resume)) {
			$this->log("Error: Failed to download $file. Check your permissions and credentials.");
			$this->log(
				/* translators: %s: File name */
				sprintf(__('Error: Failed to download %s.', 'updraftplus'), $file).' '.
				__('Check your permissions and credentials.', 'updraftplus'),
			'error');
			return false;
		}

		// This instructs the caller to look at the file pointer's position (i.e. ftell($fh)) to work out how many bytes were written.
		return true;
	
	}

	/**
	 * Get the pre configuration template
	 */
	public function get_pre_configuration_template() {
		?>
		<tr class="{{get_template_css_classes false}} S3_pre_config_container">
			<td colspan="2">
				<img src="{{storage_image_url}}" alt="Amazon Web Services"><br>
				{{{xmlwriter_existence_label}}}
				{{{simplexmlelement_existence_label}}}
				{{{curl_existence_label}}}
				<br>
				<p>
				{{{console_url}}}
				{{{ssl_certificates_errors_link_text}}}
				{{{faqs}}}
				</p>
			</td>
		</tr>
		<?php
	}

	/**
	 * Get pre configuration template engine for remote method which is S3 Compatible
	 * DEVELOPER NOTE: Please don't use/call this method anymore as it was used by Amazon S3 and S3-Compatible (Generic) storage, and it's consider to be removed in future versions. Once Amazon S3 and S3-Compatible templates are CSP-compliant, this should be removed and should be placed in the class child instead of the base class.
	 *
	 * @param String $key             Remote storage method key which is unique
	 * @param String $whoweare_short  Remote storage method short name which is prefix of field label generally
	 * @param String $whoweare_long   Remote storage method long name which is generally used in instructions
	 * @param String $console_descrip Remote storage method console description. It is used console link text like "from your %s console"
	 * @param String $console_url     Remote storage method console url. It is used for get credential instruction
	 * @param String $opening_html    HTML to appear first inside the container
	 */
	protected function get_pre_configuration_template_engine($key, $whoweare_short, $whoweare_long, $console_descrip, $console_url, $opening_html = '') {
		$classes = $this->get_css_classes(false);
		?>
		<tr class="<?php echo esc_attr($classes . ' ' . $whoweare_short . '_pre_config_container');?>">
			<td colspan="2">
				<?php echo wp_kses_post($opening_html).'<br>'; ?>
				<?php

					global $updraftplus_admin;

					$use_s3_class = $this->indicate_s3_class();

					if ('UpdraftPlus_S3_Compat' == $use_s3_class && !class_exists('XMLWriter')) {
						$updraftplus_admin->show_double_warning(
							'<strong>'.__('Warning', 'updraftplus').':</strong> '.
							/* translators: %s: Required PHP module */
							sprintf(__("Your web server's PHP installation does not include a required module (%s).", 'updraftplus'), 'XMLWriter').' '.
							__("Please contact your web hosting provider's support and ask for them to enable it.", 'updraftplus')
						);
					}

					if (!class_exists('SimpleXMLElement')) {
						$updraftplus_admin->show_double_warning(
							'<strong>'.__('Warning', 'updraftplus').':</strong> '.
							/* translators: %s: Required module name */
							sprintf(__('Your web server\'s PHP installation does not included a required module (%s).', 'updraftplus'), 'SimpleXMLElement').' '.
							__("Please contact your web hosting provider's support.", 'updraftplus').' '.
							/* translators: 1: Module name, 2: Required module name */
							sprintf(__('UpdraftPlus\'s %1$s module <strong>requires</strong> %2$s.', 'updraftplus'), $whoweare_long, 'SimpleXMLElement').' '.
							__('Please do not file any support requests; there is no alternative.', 'updraftplus'),
							$key
						);
					}
					$updraftplus_admin->curl_check($whoweare_long, true, $key);
				?>
				<br>
				<p>
					<?php
						if ($console_url) {
							$a_tag_html = array('a' => array('href' => array()));
							echo wp_kses(
								/* translators: 1: Console URL, 2: Console description, 3: Service name */
								sprintf(__('Get your access key and secret key from your <a href="%1$s">%2$s console</a>, then pick a (globally unique - all %3$s users) bucket name (letters and numbers) (and optionally a path) to use for storage.', 'updraftplus'), $console_url, $console_descrip, $whoweare_long),
								$a_tag_html
							).' '.esc_html__('This bucket will be created for you if it does not already exist.', 'updraftplus');
						}
					?>

					<a href="<?php echo esc_url(apply_filters("updraftplus_com_link", "https://teamupdraft.com/documentation/updraftplus/topics/backing-up/troubleshooting/i-get-ssl-certificate-errors-when-backing-up-and-or-restoring/?utm_source=udp-plugin&utm_medium=referral&utm_campaign=paac&utm_content=errors-about-ssl-certificates&utm_creative_format=text"));?>" target="_blank"><?php esc_html_e('If you see errors about SSL certificates, then please go here for help.', 'updraftplus');?></a>

					<a href="<?php echo esc_url(apply_filters("updraftplus_com_link", "https://teamupdraft.com/documentation/updraftplus/topics/cloud-storage/amazon-s3/faqs?utm_source=udp-plugin&utm_medium=referral&utm_campaign=paac&utm_content=amazon-s3-faqs&utm_creative_format=text"));?>" target="_blank">
					<?php
						if ('s3' == $key) echo esc_html(sprintf(
							/* translators: %s: FAQ category */
							__('Other %s FAQs.', 'updraftplus'),
							'S3'
						));
					?>
					</a>
				</p>
			</td>
		</tr>
	<?php
	}

	/**
	 * Get the configuration template
	 *
	 * @return String - the template, ready for substitutions to be carried out
	 */
	public function get_configuration_template() {
		// White: https://d36cz9buwru1tt.cloudfront.net/Powered-by-Amazon-Web-Services.jpg
		// Black: https://awsmedia.s3.amazonaws.com/AWS_logo_poweredby_black_127px.png
		ob_start();
		?>
		{{#ifeq "s3" method_id}}
			{{#> s3_additional_configuration_top}}
			{{/s3_additional_configuration_top}}
		{{else}}
			{{#> s3generic_additional_configuration_top}}
			{{/s3generic_additional_configuration_top}}
		{{/ifeq}}
		<tr class="{{get_template_css_classes true}}">
			<th>{{input_access_key_label}}:</th>
			<td><input class="updraft_input--wide udc-wd-600" data-updraft_settings_test="accesskey" type="text" autocomplete="off" id="{{get_template_input_attribute_value "id" "accesskey"}}" name="{{get_template_input_attribute_value "name" "accesskey"}}" value="{{accesskey}}" /></td>
		</tr>
		<tr class="{{get_template_css_classes true}}">
			<th>{{input_secret_key_label}}:</th>
			<td><input class="updraft_input--wide udc-wd-600" data-updraft_settings_test="secretkey" type="{{input_secret_key_type}}" autocomplete="off" id="{{get_template_input_attribute_value "id" "secretkey"}}" name="{{get_template_input_attribute_value "name" "secretkey"}}" value="{{secretkey}}" /></td>
		</tr>
		<tr class="{{get_template_css_classes true}}">
			<th>{{input_location_label}}:</th>
			<td>{{method_id}}://<input class="updraft_input--wide udc-wd-600" data-updraft_settings_test="path" title="{{input_location_title}}" type="text" id="{{get_template_input_attribute_value "id" "path"}}" name="{{get_template_input_attribute_value "name" "path"}}" value="{{path}}" /></td>
		</tr>
		{{#ifeq "s3" method_id}}
			{{#> s3_additional_configuration_bottom}}
			{{/s3_additional_configuration_bottom}}
		{{else}}
			{{#> s3generic_additional_configuration_bottom}}
			{{/s3generic_additional_configuration_bottom}}
		{{/ifeq}}
		{{{get_template_test_button_html method_display_name}}}
		<?php
		return ob_get_clean();
	}

	/**
	 * Get partial templates associated to the corresponding backup module (remote storage object)
	 *
	 * @return Array an associative array keyed by names of the partial template
	 */
	public function get_partial_templates() {
		return wp_parse_args(apply_filters('updraft_'.$this->get_id().'_partial_templates', array()), parent::get_partial_templates());
	}
	
	/**
	 * Modifies handerbar template options
	 *
	 * @param array $opts
	 * @return Array - Modified handerbar template options
	 */
	public function transform_options_for_template($opts) {
		return apply_filters('updraftplus_options_s3_options', $opts);
	}
	
	/**
	 * Get configuration template engine for remote method which is S3 Compatible
	 * DEVELOPER NOTE: Please don't use/call this method anymore as it was used by Amazon S3 and S3-Compatible (Generic) storage, and it's consider to be removed in future versions. Once Amazon S3 and S3-Compatible templates are CSP-compliant, this should be removed and should be placed in the class child instead of the base class.
	 *
	 * @param String $key             Remote storage method key which is unique
	 * @param String $whoweare_short  Remote storage method short name which is prefix of field label generally
	 * @param String $whoweare_long   Remote storage method long name which is generally used in instructions
	 * @param String $console_descrip Remote storage method console description. It is used console link text like "from your %s console"
	 * @param String $console_url     Remote storage method console url. It is used for get credential instruction
	 * @param String $img_html        Image html tag
	 *
	 * @return String $template_str handlebars template string
	 */
	public function get_configuration_template_engine($key, $whoweare_short, $whoweare_long, $console_descrip, $console_url, $img_html = '') {// phpcs:ignore VariableAnalysis.CodeAnalysis.VariableAnalysis.UnusedVariable -- $whoweare_long, $console_descrip, $console_url, $img_html unused
		global $updraftplus;
		ob_start();
		$classes = $this->get_css_classes();
		$template_str = '';
		
		if ('s3' == $key && version_compare(PHP_VERSION, '5.3.3', '>=') && class_exists('UpdraftPlus_Addon_S3_Enhanced')) {
		?>
			<tr class="<?php echo esc_attr($classes);?>">
				<td colspan="2">
				<?php
					echo wp_kses_post(apply_filters('updraft_s3_apikeysetting', '<a href="'.$updraftplus->get_url('premium').'" target="_blank"><em>'.__('To create a new IAM sub-user and access key that has access only to this bucket, upgrade to Premium.', 'updraftplus').'</em></a>'));
				?>
				</td>
			</tr>
		<?php
		}
		?>

		<tr class="<?php echo esc_attr($classes);?>">
			<th>
				<?php
					/* translators: %s: Access key type */
					echo esc_html(sprintf(__('%s access key', 'updraftplus'), $whoweare_short));
				?>:
			</th>
			<td><input class="updraft_input--wide" data-updraft_settings_test="accesskey" type="text" autocomplete="off" <?php $this->output_settings_field_name_and_id('accesskey');?> value="{{accesskey}}" /></td>
		</tr>
		<tr class="<?php echo esc_attr($classes);?>">
			<th>
				<?php
					/* translators: %s: Secret key type */
					echo esc_html(sprintf(__('%s secret key', 'updraftplus'), $whoweare_short));
				?>:
			</th>
			<td><input class="updraft_input--wide" data-updraft_settings_test="secretkey" type="<?php echo esc_attr(apply_filters('updraftplus_admin_secret_field_type', 'password')); ?>" autocomplete="off" <?php $this->output_settings_field_name_and_id('secretkey');?> value="{{secretkey}}" /></td>
		</tr>
		<tr class="<?php echo esc_attr($classes);?>">
			<th>
				<?php
					/* translators: %s: Location type */
					echo esc_html(sprintf(__('%s location', 'updraftplus'), $whoweare_short));
				?>:
			</th>
			<td><?php echo esc_html($key); ?>://<input class="updraft_input--wide" data-updraft_settings_test="path" title="<?php echo esc_attr(__('Enter only a bucket name or a bucket and path.', 'updraftplus').' '.__('Examples: mybucket, mybucket/mypath', 'updraftplus')); ?>" type="text" <?php $this->output_settings_field_name_and_id('path');?> value="{{path}}" /></td>
		</tr>
		<?php
		$template_str .= ob_get_clean();
		$template_str .= $this->get_partial_configuration_template_for_endpoint();
		$template_str .= apply_filters('updraft_'.$key.'_extra_storage_options_configuration_template', '', $this);
		$template_str .= $this->get_test_button_html($whoweare_short);
		return $template_str;
	}

	/**
	 * Get handlebar partial template string for endpoint of s3 compatible remote storage method. Other child class can extend it.
	 * DEVELOPER NOTE: Please don't use/call this method anymore as it was used by S3-Compatible (Generic) storage, and it's consider to be removed in future versions. Once Amazon S3-Compatible templates is CSP-compliant, this should be removed and should be placed in the class child instead of the base class.
	 *
	 * @return String - the partial template
	 */
	protected function get_partial_configuration_template_for_endpoint() {
		return '';
	}

	/**
	 * Retrieve a list of template properties by taking all the persistent variables and methods of the parent class and combining them with the ones that are unique to this module, also the necessary HTML element attributes and texts which are also unique only to this backup module
	 * NOTE: Please sanitise all strings that are required to be shown as HTML content on the frontend side (i.e. wp_kses()), or any other technique to prevent XSS attacks that could come via WP hooks
	 *
	 * @return Array an associative array keyed by names that describe themselves as they are
	 */
	public function get_template_properties() {
		global $updraftplus, $updraftplus_admin;

		$xmlwriter_existence_label = '';
		if (!apply_filters('updraftplus_s3_xmlwriter_exists', 'UpdraftPlus_S3_Compat' != $this->indicate_s3_class() || class_exists('XMLWriter'))) {
			$xmlwriter_existence_label = wp_kses(
				$updraftplus_admin->show_double_warning(
					'<strong>'.__('Warning', 'updraftplus').':</strong> '.
					/* translators: %s: Required module name */
					sprintf(__("Your web server's PHP installation does not include a required module (%s).", 'updraftplus'), 'XMLWriter').' '.
					__("Please contact your web hosting provider's support and ask for them to enable it.", 'updraftplus'),
					$this->get_id(),
					false
				),
				$this->allowed_html_for_content_sanitisation()
			);
		}

		$simplexmlelement_existence_label = '';
		if (!apply_filters('updraftplus_s3_simplexmlelement_exists', class_exists('SimpleXMLElement'))) {
			$simplexmlelement_existence_label = wp_kses(
				$updraftplus_admin->show_double_warning(
					'<strong>'.__('Warning', 'updraftplus').':</strong> '.
					/* translators: %s: Required module name */
					sprintf(__('Your web server\'s PHP installation does not include a required module (%s).', 'updraftplus'), 'SimpleXMLElement').' '.
					__("Please contact your web hosting provider's support.", 'updraftplus').' '.
					/* translators: 1: Module name, 2: Required module name */
					sprintf(__('UpdraftPlus\'s %1$s module <strong>requires</strong> %2$s.', 'updraftplus'), $updraftplus->backup_methods[$this->get_id()], 'SimpleXMLElement').' '.
					__('Please do not file any support requests; there is no alternative.', 'updraftplus'),
					$this->get_id(),
					false
				),
				$this->allowed_html_for_content_sanitisation()
			);
		}

		$properties = array(
			'storage_image_url' => UPDRAFTPLUS_URL .'/images/aws_logo.png',
			'console_url' => wp_kses(
				/* translators: 1: Console URL, 2: Console name, 3: Service name */
				sprintf(__('Get your access key and secret key from your <a href="%1$s">%2$s console</a>, then pick a (globally unique - all %3$s users) bucket name (letters and numbers) (and optionally a path) to use for storage.', 'updraftplus'), 'https://aws.amazon.com/console/', 'AWS', $updraftplus->backup_methods[$this->get_id()]).' '.
				__('This bucket will be created for you if it does not already exist.', 'updraftplus'),
				$this->allowed_html_for_content_sanitisation()
			),
			'xmlwriter_existence_label' => $xmlwriter_existence_label,
			'simplexmlelement_existence_label' => $simplexmlelement_existence_label,
			'curl_existence_label' => wp_kses($updraftplus_admin->curl_check($updraftplus->backup_methods[$this->get_id()], true, $this->get_id().' hide-in-udc', false), $this->allowed_html_for_content_sanitisation()),
			'ssl_certificates_errors_link_text' => wp_kses('<a href="'.apply_filters("updraftplus_com_link", "https://teamupdraft.com/documentation/updraftplus/topics/backing-up/troubleshooting/i-get-ssl-certificate-errors-when-backing-up-and-or-restoring/?utm_source=udp-plugin&utm_medium=referral&utm_campaign=paac&utm_content=errors-about-ssl-certificates&utm_creative_format=text").'" target="_blank">'.__('If you see errors about SSL certificates, then please go here for help.', 'updraftplus').'</a>', $this->allowed_html_for_content_sanitisation()),
			'faqs' => wp_kses('<a href="'.apply_filters("updraftplus_com_link", "https://teamupdraft.com/documentation/updraftplus/topics/cloud-storage/amazon-s3/faqs?utm_source=udp-plugin&utm_medium=referral&utm_campaign=paac&utm_content=amazon-s3-faqs&utm_creative_format=text").'" target="_blank">'.sprintf(__('Other %s FAQs.', 'updraftplus'), $updraftplus->backup_methods[$this->get_id()]).'</a>', $this->allowed_html_for_content_sanitisation()),
			/* translators: %s: Access key type */
			'input_access_key_label' => sprintf(__('%s access key', 'updraftplus'), $updraftplus->backup_methods[$this->get_id()]),
			/* translators: %s: Secret key type */
			'input_secret_key_label' => sprintf(__('%s secret key', 'updraftplus'), $updraftplus->backup_methods[$this->get_id()]),
			'input_secret_key_type' => apply_filters('updraftplus_admin_secret_field_type', 'password'),
			/* translators: %s: Location type */
			'input_location_label' => sprintf(__('%s location', 'updraftplus'), $updraftplus->backup_methods[$this->get_id()]),
			'input_location_title' => __('Enter only a bucket name or a bucket and path.', 'updraftplus').' '.__('Examples: mybucket, mybucket/mypath', 'updraftplus'),
			/* translators: %s: Test settings type */
			'input_test_label' => sprintf(__('Test %s Settings', 'updraftplus'), $updraftplus->backup_methods[$this->get_id()]),
		);
		return wp_parse_args(apply_filters('updraft_'.$this->get_id().'_template_properties', array()), wp_parse_args($properties, $this->get_persistent_variables_and_methods()));
	}
	
	/**
	 * Look at the config, and decide whether or not to call self::use_dns_bucket_name()
	 *
	 * @param Object $storage - S3 Name
	 * @param String $bucket  - storage path
	 * @param Array  $config  - configuration - may not be complete at this stage, so be careful about which properties are used
	 *
	 * @return Boolean - whether or not DNS bucket naming will be used
	 */
	protected function maybe_use_dns_bucket_name($storage, $bucket, $config) {

		if ('s3' === $config['key'] && '' !== $bucket) {
			
			if (preg_match("#^([^/]+)/(.*)$#", $bucket, $pmatches)) {
				$bucket = $pmatches[1];
			} else {
				$bucket = $bucket;
			}
			// AWS SSL certificates have wildcards at one level only, i.e. *.s3.amazonaws.com, so cannot be validated if the bucket brings in a further sub-domain level
			if (false !== strstr($bucket, '.') && $storage->getuseSSL() && $storage->getUseSSLValidation()) return false;
			if (strlen($bucket) > 63) return false;
			if (preg_match("/[^a-z0-9\.-]/", $bucket)) return false;
			// A DNS bucket name cannot contain -.
			if (false !== strstr($bucket, '-.')) return false;
			// A DNS bucket name cannot contain ..
			if (false !== strstr($bucket, '..')) return false;
			// A DNS bucket name must begin with 0-9a-z
			if (!preg_match("/^[0-9a-z]/", $bucket)) return false;
			// A DNS bucket name must end with 0-9 a-z
			if (!preg_match("/[0-9a-z]$/", $bucket)) return false;
			return $this->use_dns_bucket_name($storage, $bucket);
		}
		return false;
	}
	
	/**
	 * This is not pretty, but is the simplest way to accomplish the task within the pre-existing structure (no need to re-invent the wheel of code with corner-cases debugged over years)
	 *
	 * @param  object $storage S3 Name
	 *
	 * @return Boolean - true if the operation was accepted
	 */
	public function use_dns_bucket_name($storage) {
		return is_a($storage, 'UpdraftPlus_S3_Compat') ? true : $storage->useDNSBucketName(true);
	}
	
	/**
	 * Acts as a WordPress options filter
	 *
	 * @param Array $settings - pre-filtered settings
	 *
	 * @return Array filtered settings
	 */
	public function options_filter($settings) {
		if (is_array($settings) && !empty($settings['version']) && !empty($settings['settings'])) {
			foreach ($settings['settings'] as $instance_id => $instance_settings) {
				if (!empty($instance_settings['path'])) {
					$settings['settings'][$instance_id]['path'] = trim($instance_settings['path'], "/ \t\n\r\0\x0B");
				}
			}
		}
		return $settings;
	}
	
	/**
	 * This method contains some repeated code. After getting an S3 object, it's time to see if we can access that bucket - either immediately, or via creating it, etc.
	 *
	 * @param Object $storage S3 name
	 * @param Array  $config  array of config details; if the provider does not have the concept of regions, then the key 'endpoint' is required to be set
	 * @param String $bucket  S3 Bucket
	 * @param String $path    S3 Path
	 *
	 * @return Array - N.B. May contain updated versions of $storage and $config
	 */
	protected function get_bucket_access($storage, $config, $bucket, $path) {

		$bucket_exists = false;

		$use_ssl = true;
		$ssl_ca = false;
		$nossl = $this->got_with['nossl'];
		// Ignore the 'nossl' setting if the endpoint is DigitalOcean Spaces (https://developers.digitalocean.com/documentation/v2/)
		if (!empty($config['endpoint']) && preg_match('/\.digitaloceanspaces\.com$/i', $config['endpoint'])) {
			$nossl = apply_filters('updraftplus_gets3_nossl', false, $config['endpoint'], $this->got_with['nossl']);
		}

		if (!$nossl) {
			$curl_version = function_exists('curl_version') ? curl_version() : array('features' => null);
			$curl_ssl_supported = ($curl_version['features'] && defined('CURL_VERSION_SSL') && CURL_VERSION_SSL);
			if ($curl_ssl_supported) {
				if ($this->got_with['disableverify']) {
					$ssl_ca = false;
					$this->log("Disabling verification of SSL certificates");
				} else {
					if ($this->got_with['useservercerts']) {
						$this->log("Using the server's SSL certificates");
						$ssl_ca = 'system';
					} else {
						$ssl_ca = file_exists(UPDRAFTPLUS_DIR.'/includes/cacert.pem') ? UPDRAFTPLUS_DIR.'/includes/cacert.pem' : true;
					}
				}
			} else {
				$use_ssl = false;
				$this->log("Curl/SSL is not available. Communications will not be encrypted.");
			}
		} else {
			$use_ssl = false;
			$this->log("SSL was disabled via the user's preference. Communications will not be encrypted.");
		}

		$storage->setSSL($use_ssl);
		$storage->setSSLAuth(null, null, $ssl_ca);


		// If using Amazon S3, then always prefer using host-based access
		$this->maybe_use_dns_bucket_name($storage, $bucket, $config);
		
		if ($this->provider_has_regions) {

			$storage->setExceptions(true);
			
			if ('dreamobjects' == $config['key']) {
				$endpoint = isset($config['endpoint']) ? $config['endpoint'] : '';
				$this->set_region($storage, $endpoint);
			}
			try {
				$region = @$storage->getBucketLocation($bucket);// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- Silenced to suppress errors that may arise because of the method.
				
				// We want to distinguish between an empty region (null), and an exception or missing bucket (false)
				if (empty($region) && false !== $region) $region = null;
			} catch (Exception $e) {
				$region = false;
				
				// This is not ideal, but helps with detection/trapping of other "permanent" conditions
				// All these codes are likely to indicate things that we want to be logged, rather than suppressing logging until the final method used to get a bucket location
				$curl_error_codes = array(1, 2, 3, 4, 5, 6, 7, 8, 16, 23, 26, 27, 28, 33, 35, 41, 43, 47, 48, 49, 53, 54, 55, 56, 58, 59, 60, 61, 66, 77, 81, 82, 83, 90, 91, 92, 93, 94, 95, 96, 97, 98, 99);
				if (UpdraftPlus_Options::get_updraft_option('updraft_debug_mode') || (preg_match('/\[(\d+)\]/', $e->getMessage(), $matches) && in_array($matches[1], $curl_error_codes))) {
					global $updraftplus;
					$updraftplus->log("get_bucket_access(): getBucketLocation exception (".get_class($e)."): ".$e->getMessage());
				}

				// On this 'first try', we trap these particular conditions. So, whatever S3 network call it happens on, we'll eventually get it here on the resumption.
				
				if (false !== strpos($e->getMessage(), '[RequestTimeTooSkewed]')) {
					$this->s3_exception = $e;
					return array($storage, $config, false, false);
				}
				
				// The base Amazon S3 module and child S3-Generic remote storage don't use session token to make a connection to the targeted storage server: we only use session token for Vault storage.
				// Since we don't provide credentials testing for Vault storage, this means handling session token expiry exception won't happen during credentials testing. So the fact that saved values are used here is fine, since there are no other relevant values in the absence of credentials testing.
				if (false !== strpos($e->getMessage(), 'The provided token has expired')) {
				
					$this->log($e->getMessage().": Requesting new credentials");
							
					$new_config = $this->get_config(true);

					if (empty($new_config['sessiontoken'])) $new_config['sessiontoken'] = null;
		
					if (!empty($new_config['accesskey'])) {
			
						$new_storage = $this->getS3(
							$new_config['accesskey'],
							$new_config['secretkey'],
							UpdraftPlus_Options::get_updraft_option('updraft_ssl_useservercerts'),
							UpdraftPlus_Options::get_updraft_option('updraft_ssl_disableverify'),
							UpdraftPlus_Options::get_updraft_option('updraft_ssl_nossl'),
							null,
							!empty($new_config['server_side_encryption']),
							$new_config['sessiontoken']
						);
						
						if (!is_wp_error($new_storage)) {
							// Try again
							try {
								$region = @$new_storage->getBucketLocation($bucket);// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- Silenced to suppress errors that may arise because of the method.
								// We want to distinguish between an empty region (null), and an exception or missing bucket (false)
								if (empty($region) && false !== $region) $region = null;
								// Worked this time; update the passed-in information
								$storage = $new_storage;
								$config = $new_config;
							} catch (Exception $e) {
								$region = false;
							}
						}
					}
				}
				
			}
			$storage->setExceptions(false);
		} else {
			$region = false;
			$this->set_region($storage, $config['endpoint'], $bucket);
		}

		// See if we can detect the region (which implies the bucket exists and is ours), or if not create it
		if (!$this->provider_has_regions || false === $region) {
			$storage->setExceptions(true);
			try {
				
				if (@$storage->putBucket($bucket, 'private')) {// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- Silenced to suppress errors that may arise because of the method.
					$bucket_exists = true;
				}
				
			} catch (Exception $e) {
				$this->s3_exception = $e;
				try {
					
					if (false !== @$storage->getBucket($bucket, $path, null, 1)) {// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- Silenced to suppress errors that may arise because of the method.
						$bucket_exists = true;
					}
				} catch (Exception $e) {

					// We don't put this in a separate catch block which names the exception, since we need to remain compatible with PHP 5.2
					if (is_a($storage, 'UpdraftPlus_S3_Compat') && is_a($e, 'Aws\S3\Exception\S3Exception')) {
						
						$response = $e->getResponse();
						
						if (is_null($response)) {
							$this->s3_exception = $e;
						} else {
							$xml = new SimpleXMLElement((string) $response->getBody(), LIBXML_NONET);

							if (!empty($xml->Code) && 'AuthorizationHeaderMalformed' == $xml->Code->__toString() && !empty($xml->Region)) {
	
								$this->set_region($storage, $xml->Region->__toString());
								$storage->setExceptions(false);
								
								if (false !== @$storage->getBucket($bucket, $path, null, 1)) {// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- Silenced to suppress errors that may arise because of the method.
									$bucket_exists = true;
								}
								
							} else {
								$this->s3_exception = $e;
							}
						}
					} else {
						$this->s3_exception = $e;
					}
				}
			
			}
			$storage->setExceptions(false);
			
		} else {
			$bucket_exists = true;
		}
		
		// For a region-less S3 system, we set this to true so that we can carry on trying anyway, since the behaviour of different S3-compatible systems can vary. e.g. DigitalOcean spaces API keys allow you to create a bucket.
		if (!$this->provider_has_regions) {
			$bucket_exists = true;
		} elseif ($bucket_exists) {
			if ('s3' == $config['key'] || 'updraftvault' == $config['key']) {
				$this->set_region($storage, $region, $bucket);
			} elseif (!empty($region)) {
				// N.B. region non-empty here implies that it's dreamobjects; but in that case, we already called set_region earlier. So, this is now commented (May 2021)
				// if (!$endpoint) $this->set_region($storage, $endpoint, $bucket);
			}
		}
		
		return array($storage, $config, $bucket_exists, $region);
		
	}

	/**
	 * Perform a test of user-supplied credentials, and echo the result
	 *
	 * @param Array $posted_settings - settings to test
	 */
	public function credentials_test($posted_settings) {

		if (empty($posted_settings['accesskey'])) {
			echo esc_html(sprintf(
				/* translators: %s: Missing input type */
				__("Failure: No %s was given.", 'updraftplus'),
				__('API key', 'updraftplus')
			));
			return;
		}
		if (empty($posted_settings['secretkey'])) {
			echo esc_html(sprintf(
				/* translators: %s: Missing input type */
				__("Failure: No %s was given.", 'updraftplus'),
				__('API secret', 'updraftplus')
			));
			return;
		}

		$key = $posted_settings['accesskey'];
		$secret = $posted_settings['secretkey'];
		$path = $posted_settings['path'];
		$useservercerts = isset($posted_settings['useservercerts']) ? absint($posted_settings['useservercerts']) : 0;
		$disableverify = isset($posted_settings['disableverify']) ? absint($posted_settings['disableverify']) : 0;
		$nossl = isset($posted_settings['nossl']) ? absint($posted_settings['nossl']) : 0;
		$endpoint = isset($posted_settings['endpoint']) ? trim($posted_settings['endpoint']) : '';
		$sse = empty($posted_settings['server_side_encryption']) ? false : true;

		if (preg_match("#^/*([^/]+)/(.*)$#", $path, $bmatches)) {
			$bucket = $bmatches[1];
			$path = trailingslashit($bmatches[2]);
		} else {
			$bucket = $path;
			$path = "";
		}

		if (empty($bucket)) {
			esc_html_e("Failure: No bucket details were given.", 'updraftplus');
			return;
		}
		
		if (!$this->provider_has_regions && '' == $endpoint) {
			esc_html_e("Failure: No endpoint details were given.", 'updraftplus');
			return;
		}
		
		$config = $this->get_config();
		
		if ('' !== $endpoint) $config['endpoint'] = $endpoint;
		
		$whoweare = $config['whoweare'];
		
		$session_token = empty($config['sessiontoken']) ? null : $config['sessiontoken'];
		
		$storage = $this->getS3($key, $secret, $useservercerts, $disableverify, $nossl, null, $sse, $session_token);
		if (is_wp_error($storage)) {
			foreach ($storage->get_error_messages() as $msg) {
				echo esc_html($msg)."\n";
			}
			return;
		}

		if (!empty($posted_settings['signature_version'])) $config['signature_version'] = $posted_settings['signature_version'];

		if (!empty($posted_settings['bucket_access_style']) && 'virtual_host_style' === $posted_settings['bucket_access_style']) {
			$storage->useDNSBucketName(true, $bucket);
		} else {
			$storage->useDNSBucketName(false, $bucket);
		}

		list($storage, $config, $bucket_exists, $region) = $this->get_bucket_access($storage, $config, $bucket, $path);
		
		$bucket_verb = '';
		if ($this->provider_has_regions && $region) {
			if ('s3' == $config['key']) {
				$bucket_verb = __('Region', 'updraftplus').": $region: ";
			}
		}

		if (empty($bucket_exists)) {
		
			echo esc_html(
				__('Failure: We could not successfully access or create such a bucket.', 'updraftplus').' '.
				/* translators: %s: Service name */
				sprintf(__('Please check your access credentials, and if those are correct then try another bucket name (as another %s user may already have taken your name).', 'updraftplus'), $whoweare)
			);
			
			/* translators: %s: Service name */
			if (!empty($this->s3_exception)) echo "\n\n".esc_html(sprintf(__('The error reported by %s was:', 'updraftplus'), $whoweare).' '.$this->s3_exception);
			
			/* translators: %s: Service name */
			if ('s3' == $config['key'] && 'AK' != substr($key, 0, 2)) echo "\n\n".esc_html(sprintf(__('The AWS access key looks to be wrong (valid %s access keys begin with "AK")', 'updraftplus'), $whoweare));
		
		} else {
		
			$try_file = md5(rand());

			$storage->setExceptions(true);
			try {
				if (!$storage->putObjectString($try_file, $bucket, $path.$try_file)) {
					echo esc_html(__('Failure', 'updraftplus').": {$bucket_verb}".__('We successfully accessed the bucket, but the attempt to create a file in it failed.', 'updraftplus'));
				} else {
					echo esc_html(__('Success', 'updraftplus').": {$bucket_verb}".__('We accessed the bucket, and were able to create files within it.', 'updraftplus')).' ';
					$comm_with = ('' !== $endpoint) ? $endpoint : $config['whoweare_long'];
					if ($storage->getuseSSL()) {
						/* translators: %s: Communication entity */
						echo esc_html(sprintf(__('The communication with %s was encrypted.', 'updraftplus'), $comm_with));
					} else {
						/* translators: %s: Communication entity */
						echo esc_html(sprintf(__('The communication with %s was not encrypted.', 'updraftplus'), $comm_with));
					}
					$create_success = true;
				}
			} catch (Exception $e) {
				echo esc_html(__('Failure', 'updraftplus').": {$bucket_verb}".__('We successfully accessed the bucket, but the attempt to create a file in it failed.', 'updraftplus').' '.__('Please check your access credentials.', 'updraftplus').' ('.$e->getMessage().')');
			}

			if (!empty($create_success)) {
				try {
					@$storage->deleteObject($bucket, $path.$try_file);// phpcs:ignore Generic.PHP.NoSilencedErrors.Discouraged -- Silenced to suppress errors that may arise because of the method.
				} catch (Exception $e) {
					echo esc_html(' '.__('Delete failed:', 'updraftplus').' '.$e->getMessage());
				}
			}

		}

	}

	/**
	 * Check whether options have been set up by the user, or not
	 *
	 * @param Array $opts - the potential options
	 *
	 * @return Boolean
	 */
	public function options_exist($opts) {
		if (is_array($opts) && isset($opts['accesskey']) && '' != $opts['accesskey'] && isset($opts['secretkey'])) return true;
		return false;
	}
}
