<?php
namespace W3TC;

/**
 * Amazon S3 CDN engine
 */

if ( !class_exists( 'S3' ) ) {
	require_once W3TC_LIB_DIR . '/S3.php';
}

/**
 * class CdnEngine_S3
 */
class CdnEngine_S3 extends CdnEngine_Base {
	/**
	 * S3 object
	 *
	 * @var S3
	 */
	var $_s3 = null;

	/**
	 * PHP5 Constructor
	 *
	 * @param array   $config
	 */
	function __construct( $config = array() ) {
		$config = array_merge( array(
				'key' => '',
				'secret' => '',
				'bucket' => '',
				'bucket_location' => '',
				'cname' => array(),
			), $config );

		parent::__construct( $config );
	}

	/**
	 * Formats URL
	 *
	 * @param string  $path
	 * @return string
	 */
	function _format_url( $path ) {
		$domain = $this->get_domain( $path );

		if ( $domain ) {
			$scheme = $this->_get_scheme();

			// it does not support '+', requires '%2B'
			$path = str_replace( '+', '%2B', $path );
			$url = sprintf( '%s://%s/%s', $scheme, $domain, $path );

			return $url;
		}

		return false;
	}

	/**
	 * Inits S3 object
	 *
	 * @param string  $error
	 * @return boolean
	 */
	function _init( &$error ) {
		if ( empty( $this->_config['key'] ) ) {
			$error = 'Empty access key.';

			return false;
		}

		if ( empty( $this->_config['secret'] ) ) {
			$error = 'Empty secret key.';

			return false;
		}

		if ( empty( $this->_config['bucket'] ) ) {
			$error = 'Empty bucket.';

			return false;
		}

		if ( empty( $this->_config['bucket_location'] ) ) {
			$region = '';
			$endpoint = 's3.amazonaws.com';
		} else {
			$region = $this->_config['bucket_location'];
			$endpoint = 's3.dualstack.' . $region . '.amazonaws.com';
		}

		$this->_s3 = new \S3( $this->_config['key'], $this->_config['secret'],
			false, $endpoint, $region );
		if ( empty( $region ) ) {
			$this->_s3->setSignatureVersion( 'v2' );
		}

		return true;
	}

	/**
	 * Uploads files to S3
	 *
	 * @param array   $files
	 * @param array   $results
	 * @param boolean $force_rewrite
	 * @return boolean
	 */
	function upload( $files, &$results, $force_rewrite = false,
		$timeout_time = NULL ) {
		$error = null;

		if ( !$this->_init( $error ) ) {
			$results = $this->_get_results( $files, W3TC_CDN_RESULT_HALT, $error );

			return false;
		}

		foreach ( $files as $file ) {
			$local_path = $file['local_path'];
			$remote_path = $file['remote_path'];

			// process at least one item before timeout so that progress goes on
			if ( !empty( $results ) ) {
				if ( !is_null( $timeout_time ) && time() > $timeout_time ) {
					return 'timeout';
				}
			}

			$results[] = $this->_upload( $file, $force_rewrite );

			if ( $this->_config['compression'] && $this->_may_gzip( $remote_path ) ) {
				$file['remote_path_gzip'] = $remote_path . $this->_gzip_extension;
				$results[] = $this->_upload_gzip( $file, $force_rewrite );
			}
		}

		return !$this->_is_error( $results );
	}

	/**
	 * Uploads single file to S3
	 *
	 * @param array   CDN file array
	 * @param boolean $force_rewrite
	 * @return array
	 */
	function _upload( $file, $force_rewrite = false ) {
		$local_path = $file['local_path'];
		$remote_path = $file['remote_path'];

		if ( !file_exists( $local_path ) ) {
			return $this->_get_result( $local_path, $remote_path,
				W3TC_CDN_RESULT_ERROR, 'Source file not found.', $file );
		}

		if ( !$force_rewrite ) {
			$this->_set_error_handler();
			$info = @$this->_s3->getObjectInfo( $this->_config['bucket'], $remote_path );
			$this->_restore_error_handler();

			if ( $info ) {
				$hash = @md5_file( $local_path );
				$s3_hash = ( isset( $info['hash'] ) ? $info['hash'] : '' );

				if ( $hash === $s3_hash ) {
					return $this->_get_result( $local_path, $remote_path,
						W3TC_CDN_RESULT_OK, 'Object up-to-date.', $file );
				}
			}
		}

		$headers = $this->_get_headers( $file );

		$this->_set_error_handler();
		$result = @$this->_s3->putObjectFile( $local_path, $this->_config['bucket'], $remote_path, \S3::ACL_PUBLIC_READ, array(), $headers );
		$this->_restore_error_handler();

		if ( $result ) {
			return $this->_get_result( $local_path, $remote_path,
				W3TC_CDN_RESULT_OK, 'OK', $file );
		}

		if ( strpos( $this->_get_last_error(), 'AWS4-HMAC-SHA256' ) !== false ) {
			$error = "Bucket location region is incorrect. Please select the right one.";
		} else {
			$error = sprintf( 'Unable to put object (%s).', $this->_get_last_error() );
		}

		return $this->_get_result( $local_path, $remote_path,
			W3TC_CDN_RESULT_ERROR, $error, $file );
	}

	/**
	 * Uploads gzip version of file
	 *
	 * @param string  $local_path
	 * @param string  $remote_path
	 * @param boolean $force_rewrite
	 * @return array
	 */
	function _upload_gzip( $file, $force_rewrite = false ) {
		$local_path = $file['local_path'];
		$remote_path = $file['remote_path_gzip'];

		if ( !function_exists( 'gzencode' ) ) {
			return $this->_get_result( $local_path, $remote_path,
				W3TC_CDN_RESULT_ERROR, "GZIP library doesn't exist.", $file );
		}

		if ( !file_exists( $local_path ) ) {
			return $this->_get_result( $local_path, $remote_path,
				W3TC_CDN_RESULT_ERROR, 'Source file not found.', $file );
		}

		$contents = @file_get_contents( $local_path );

		if ( $contents === false ) {
			return $this->_get_result( $local_path, $remote_path,
				W3TC_CDN_RESULT_ERROR, 'Unable to read file.', $file );
		}

		$data = gzencode( $contents );

		if ( !$force_rewrite ) {
			$this->_set_error_handler();
			$info = @$this->_s3->getObjectInfo( $this->_config['bucket'], $remote_path );
			$this->_restore_error_handler();

			if ( $info ) {
				$hash = md5( $data );
				$s3_hash = ( isset( $info['hash'] ) ? $info['hash'] : '' );

				if ( $hash === $s3_hash ) {
					return $this->_get_result( $local_path, $remote_path,
						W3TC_CDN_RESULT_OK, 'Object up-to-date.', $file );
				}
			}
		}

		$headers = $this->_get_headers( $file );
		$headers = array_merge( $headers, array(
				'Vary' => 'Accept-Encoding',
				'Content-Encoding' => 'gzip'
			) );

		$this->_set_error_handler();
		$result = @$this->_s3->putObjectString( $data, $this->_config['bucket'], $remote_path, \S3::ACL_PUBLIC_READ, array(), $headers );
		$this->_restore_error_handler();

		if ( $result ) {
			return $this->_get_result( $local_path, $remote_path,
				W3TC_CDN_RESULT_OK, 'OK', $file );
		}

		if ( strpos( $this->_get_last_error(), 'AWS4-HMAC-SHA256' ) !== false ) {
			$error = "Bucket location region is incorrect. Please select the right one.";
		} else {
			$error = sprintf( 'Unable to put object (%s).', $this->_get_last_error() );
		}

		return $this->_get_result( $local_path, $remote_path,
			W3TC_CDN_RESULT_ERROR, $error, $file );
	}

	/**
	 * Deletes files from S3
	 *
	 * @param array   $files
	 * @param array   $results
	 * @return boolean
	 */
	function delete( $files, &$results ) {
		$error = null;

		if ( !$this->_init( $error ) ) {
			$results = $this->_get_results( $files, W3TC_CDN_RESULT_HALT, $error );

			return false;
		}

		foreach ( $files as $file ) {
			$local_path = $file['local_path'];
			$remote_path = $file['remote_path'];

			$this->_set_error_handler();
			$result = @$this->_s3->deleteObject( $this->_config['bucket'], $remote_path );
			$this->_restore_error_handler();

			if ( $result ) {
				$results[] = $this->_get_result( $local_path, $remote_path,
					W3TC_CDN_RESULT_OK, 'OK', $file );
			} else {
				$results[] = $this->_get_result( $local_path, $remote_path,
					W3TC_CDN_RESULT_ERROR,
					sprintf( 'Unable to delete object (%s).',
						$this->_get_last_error() ),
					$file );
			}

			if ( $this->_config['compression'] ) {
				$remote_path_gzip = $remote_path . $this->_gzip_extension;

				$this->_set_error_handler();
				$result = @$this->_s3->deleteObject( $this->_config['bucket'], $remote_path_gzip );
				$this->_restore_error_handler();

				if ( $result ) {
					$results[] = $this->_get_result( $local_path,
						$remote_path_gzip, W3TC_CDN_RESULT_OK, 'OK', $file );
				} else {
					$results[] = $this->_get_result( $local_path,
						$remote_path_gzip, W3TC_CDN_RESULT_ERROR,
						sprintf( 'Unable to delete object (%s).',
							$this->_get_last_error() ),
						$file );
				}
			}
		}

		return !$this->_is_error( $results );
	}

	/**
	 * Tests S3
	 *
	 * @param string  $error
	 * @return boolean
	 */
	function test( &$error ) {
		if ( !parent::test( $error ) ) {
			return false;
		}

		$string = 'test_s3_' . md5( time() );

		if ( !$this->_init( $error ) ) {
			return false;
		}

		$this->_set_error_handler();

		$buckets = @$this->_s3->listBuckets();

		if ( $buckets === false ) {
			$error = sprintf( 'Unable to list buckets (%s).', $this->_get_last_error() );

			$this->_restore_error_handler();

			return false;
		}

		if ( !in_array( $this->_config['bucket'], (array) $buckets ) ) {
			$error = sprintf( 'Bucket doesn\'t exist: %s.', $this->_config['bucket'] );

			$this->_restore_error_handler();

			return false;
		}

		if ( !@$this->_s3->putObjectString( $string, $this->_config['bucket'], $string, \S3::ACL_PUBLIC_READ ) ) {
			if ( strpos( $this->_get_last_error(), 'AWS4-HMAC-SHA256' ) !== false ) {
				$error = "Bucket location region is incorrect. Please select the right one.";
			} else {
				$error = sprintf( 'Unable to put object (%s).', $this->_get_last_error() );
			}

			$this->_restore_error_handler();

			return false;
		}

		if ( !( $object = @$this->_s3->getObject( $this->_config['bucket'], $string ) ) ) {
			$error = sprintf( 'Unable to get object (%s).', $this->_get_last_error() );

			$this->_restore_error_handler();

			return false;
		}

		if ( $object->body != $string ) {
			$error = 'Objects are not equal.';

			@$this->_s3->deleteObject( $this->_config['bucket'], $string );
			$this->_restore_error_handler();

			return false;
		}

		if ( !@$this->_s3->deleteObject( $this->_config['bucket'], $string ) ) {
			$error = sprintf( 'Unable to delete object (%s).', $this->_get_last_error() );

			$this->_restore_error_handler();

			return false;
		}

		$this->_restore_error_handler();

		return true;
	}

	/**
	 * Returns CDN domain
	 *
	 * @return array
	 */
	function get_domains() {
		if ( !empty( $this->_config['cname'] ) ) {
			return (array) $this->_config['cname'];
		} elseif ( !empty( $this->_config['bucket'] ) ) {
			$domain = sprintf( '%s.s3.amazonaws.com', $this->_config['bucket'] );

			return array(
				$domain
			);
		}

		return array();
	}

	/**
	 * Returns via string
	 *
	 * @return string
	 */
	function get_via() {
		return sprintf( 'Amazon Web Services: S3: %s', parent::get_via() );
	}

	/**
	 * Creates bucket
	 *
	 * @param string  $container_id
	 * @param string  $error
	 * @return boolean
	 */
	function create_container( &$container_id, &$error ) {
		if ( !$this->_init( $error ) ) {
			return false;
		}

		$this->_set_error_handler();

		$buckets = @$this->_s3->listBuckets();

		if ( $buckets === false ) {
			$error = sprintf( 'Unable to list buckets (%s).', $this->_get_last_error() );

			$this->_restore_error_handler();

			return false;
		}

		if ( in_array( $this->_config['bucket'], (array) $buckets ) ) {
			$error = sprintf( 'Bucket already exists: %s.', $this->_config['bucket'] );

			$this->_restore_error_handler();

			return false;
		}

		if ( empty( $this->_config['bucket_acl'] ) ) {
			$this->_config['bucket_acl'] = \S3::ACL_PRIVATE;
		}

		if ( !isset( $this->_config['bucket_location'] ) ) {
			$this->_config['bucket_location'] = \S3::LOCATION_US;
		}

		if ( !@$this->_s3->putBucket( $this->_config['bucket'], $this->_config['bucket_acl'], $this->_config['bucket_location'] ) ) {
			$error = sprintf( 'Unable to create bucket: %s (%s).', $this->_config['bucket'], $this->_get_last_error() );

			$this->_restore_error_handler();

			return false;
		}

		$this->_restore_error_handler();

		return true;
	}

	/**
	 * How and if headers should be set
	 *
	 * @return string W3TC_CDN_HEADER_NONE, W3TC_CDN_HEADER_UPLOADABLE, W3TC_CDN_HEADER_MIRRORING
	 */
	function headers_support() {
		return W3TC_CDN_HEADER_UPLOADABLE;
	}
}