%'
				OR `meta_value` LIKE '%smush_png_path%')"
		);

		return $images_to_restore;
	}

	/**
	 * Get the number of attachments that can be restored.
	 *
	 * @since 3.2.2
	 */
	public function get_image_count() {
		check_ajax_referer( 'smush_bulk_restore' );
		// Check for permission.
		if ( ! Helper::is_user_allowed( 'manage_options' ) ) {
			wp_die( esc_html__( 'Unauthorized', 'wp-smushit' ), 403 );
		}
		wp_send_json_success(
			array(
				'items' => $this->get_attachments_with_backups(),
			)
		);
	}

	/**
	 * Bulk restore images from the modal.
	 *
	 * @since 3.2.2
	 */
	public function restore_step() {
		check_ajax_referer( 'smush_bulk_restore' );

		// Check for permission.
		if ( ! Helper::is_user_allowed( 'manage_options' ) ) {
			wp_die( esc_html__( 'Unauthorized', 'wp-smushit' ), 403 );
		}

		$id = filter_input( INPUT_POST, 'item', FILTER_SANITIZE_NUMBER_INT, FILTER_NULL_ON_FAILURE );

		$media_item = Media_Item_Cache::get_instance()->get( $id );
		if ( ! $media_item->is_mime_type_supported() ) {
			wp_send_json_error(
				array(
					/* translators: %s: Error message */
					'error_msg' => sprintf( esc_html__( 'Image not restored. %s', 'wp-smushit' ), $media_item->get_errors()->get_error_message() ),
				)
			);
		}

		$optimizer = new Media_Item_Optimizer( $media_item );
		$status    = $id && $optimizer->restore();

		$file_name = $media_item->get_full_or_scaled_size()->get_file_name();

		wp_send_json_success(
			array(
				'success' => $status,
				'src'     => ! empty( $file_name ) ? $file_name : __( 'Error getting file name', 'wp-smushit' ),
				'thumb'   => wp_get_attachment_image( $id ),
				'link'    => Helper::get_image_media_link( $id, $file_name, true ),
			)
		);
	}

	/**
	 * Returns the backup path for attachment
	 *
	 * @param string $attachment_path  Attachment path.
	 *
	 * @return string
	 */
	public function get_image_backup_path( $attachment_path ) {
		if ( empty( $attachment_path ) ) {
			return '';
		}

		$path = pathinfo( $attachment_path );

		if ( empty( $path['extension'] ) ) {
			return '';
		}

		return trailingslashit( $path['dirname'] ) . $path['filename'] . '.bak.' . $path['extension'];
	}

	/**
	 * Clear up all the backup files for the image while deleting the image.
	 *
	 * @since 3.9.6
	 * Note, we only call this method while deleting the image, as it will delete
	 * .bak file and might be the original file too.
	 *
	 * Note, for the old version < 3.9.6 we also save all PNG files (original file and thumbnails)
	 * when the site doesn't compress original file.
	 * But it's not safe to remove them if the user add another image with the same PNG file name, and didn't convert it.
	 * So we still leave them there.
	 *
	 * @param int $attachment_id  Attachment ID.
	 */
	public function delete_backup_files( $attachment_id ) {
		$smush_meta = get_post_meta( $attachment_id, Smush::$smushed_meta_key, true );
		if ( empty( $smush_meta ) ) {
			return;
		}

		// Save list files to remove.
		$files_to_remove = array();

		$unfiltered = false;
		$file_path  = get_attached_file( $attachment_id, false );
		// We only work with the real file path, not cloud URL like S3.
		if ( false === strpos( $file_path, ABSPATH ) ) {
			$unfiltered = true;
			$file_path  = get_attached_file( $attachment_id, true );
		}
		// Remove from the cache.
		wp_cache_delete( 'images_with_backups', 'wp-smush' );

		/**
		 * We only remove the backup file from the metadata,
		 * keep the backup file from 3rd-party.
		 */
		$backup_path  = null;// Reset backup file.
		$backup_sizes = $this->get_backup_sizes( $attachment_id );
		if ( isset( $backup_sizes[ $this->backup_key ]['file'] ) ) {
			$backup_path = str_replace( wp_basename( $file_path ), wp_basename( $backup_sizes[ $this->backup_key ]['file'] ), $file_path );
			// Add to remove the backup file.
			$files_to_remove[ $this->backup_key ] = $backup_path;
		}

		// Check the backup file from resized PNG file (< 3.9.6).
		if ( isset( $backup_sizes['smush_png_path']['file'] ) ) {
			$backup_path = str_replace( wp_basename( $file_path ), wp_basename( $backup_sizes['smush_png_path']['file'] ), $file_path );
			// Add to remove the backup file.
			$files_to_remove['smush_png_path'] = $backup_path;
		}

		if ( ! $backup_path ) {
			// Check for legacy original file path. It's for old version < V.2.7.0.
			$original_file = get_post_meta( $attachment_id, 'wp-smush-original_file', true );
			if ( ! empty( $original_file ) ) {
				// For old version < v.2.7.0, we are saving meta['file'] or _wp_attached_file.
				$backup_path = Helper::original_file( $original_file );
				// Add to remove the backup file.
				$files_to_remove[] = $backup_path;
			}
		}

		// Check meta for rest of the sizes.
		$meta = wp_get_attachment_metadata( $attachment_id, $unfiltered );
		if ( empty( $meta ) || empty( $meta['sizes'] ) ) {
			Helper::logger()->backup()->info( sprintf( 'Empty meta sizes [%s(%d)]', $file_path, $attachment_id ) );
			return;
		}

		foreach ( $meta['sizes'] as $size ) {
			if ( empty( $size['file'] ) ) {
				continue;
			}

			// Image path and backup path.
			$image_size_path   = path_join( dirname( $file_path ), $size['file'] );
			$image_backup_path = $this->get_image_backup_path( $image_size_path );

			// Add to remove the backup file.
			$files_to_remove[] = $image_backup_path;
		}

		// We also try to delete this file on cloud, e.g. S3.
		Helper::delete_permanently( $files_to_remove, $attachment_id, false );
	}

}