name, strlen( 'jetpack/' ) );
		}
		return $extension_name;
	}

	/**
	 * Check to see if a minimum version of Gutenberg is available. Because a Gutenberg version is not available in
	 * php if the Gutenberg plugin is not installed, if we know which minimum WP release has the required version we can
	 * optionally fall back to that.
	 *
	 * @since 1.1.0
	 *
	 * @param array  $version_requirements {
	 *     An array containing the required Gutenberg version and, if known, the WordPress version that was released with this minimum version.
	 *
	 *     @type string $gutenberg Gutenberg version.
	 *     @type string $wp        Optional. WordPress version.
	 * }
	 * @param string $slug The slug of the block or plugin that has the Gutenberg version requirement.
	 *
	 * @return boolean True if the version of Gutenberg required by the block or plugin is available.
	 */
	public static function is_gutenberg_version_available( $version_requirements, $slug ) {
		global $wp_version;

		// Bail if we don't at least have the Gutenberg version requirement, the WP version is optional.
		if ( empty( $version_requirements['gutenberg'] ) ) {
			return false;
		}

		// If running a local dev build of Gutenberg plugin GUTENBERG_DEVELOPMENT_MODE is set so assume correct version.
		if ( defined( 'GUTENBERG_DEVELOPMENT_MODE' ) && GUTENBERG_DEVELOPMENT_MODE ) {
			return true;
		}

		$version_available = false;

		// If running a production build of the Gutenberg plugin then GUTENBERG_VERSION is set, otherwise if WP version
		// with required version of Gutenberg is known check that.
		if ( defined( 'GUTENBERG_VERSION' ) ) {
			$version_available = version_compare( GUTENBERG_VERSION, $version_requirements['gutenberg'], '>=' );
		} elseif ( ! empty( $version_requirements['wp'] ) ) {
			$version_available = version_compare( $wp_version, $version_requirements['wp'], '>=' );
		}

		if (
			! $version_available
			&& ! self::is_standalone_block() // This is only useful in Jetpack.
		) {
			Jetpack_Gutenberg::set_extension_unavailable(
				$slug,
				'incorrect_gutenberg_version',
				array(
					'required_feature' => $slug,
					'required_version' => $version_requirements,
					'current_version'  => array(
						'wp'        => $wp_version,
						'gutenberg' => defined( 'GUTENBERG_VERSION' ) ? GUTENBERG_VERSION : null,
					),
				)
			);
		}

		return $version_available;
	}

	/**
	 * Get CSS classes for a block.
	 *
	 * @since 1.1.0
	 *
	 * @param string $slug  Block slug.
	 * @param array  $attr  Block attributes.
	 * @param array  $extra Potential extra classes you may want to provide.
	 *
	 * @return string $classes List of CSS classes for a block.
	 */
	public static function classes( $slug, $attr, $extra = array() ) {
		if ( empty( $slug ) ) {
			return '';
		}

		// Basic block name class.
		$classes = array(
			'wp-block-jetpack-' . $slug,
		);

		// Add alignment if provided.
		if (
			! empty( $attr['align'] )
			&& in_array( $attr['align'], array( 'left', 'center', 'right', 'wide', 'full' ), true )
		) {
			$classes[] = 'align' . $attr['align'];
		}

		// Add custom classes if provided in the block editor.
		if ( ! empty( $attr['className'] ) ) {
			$classes[] = $attr['className'];
		}

		// Add any extra classes.
		if ( is_array( $extra ) && ! empty( $extra ) ) {
			$classes = array_merge( $classes, array_filter( $extra ) );
		}

		return implode( ' ', $classes );
	}

	/**
	 * Does the page return AMP content.
	 *
	 * @since 1.1.0
	 *
	 * @return bool $is_amp_request Are we on an AMP view.
	 */
	public static function is_amp_request() {
		$is_amp_request = ( function_exists( 'is_amp_endpoint' ) && is_amp_endpoint() );

		/** This filter is documented in 3rd-party/class.jetpack-amp-support.php */
		return apply_filters( 'jetpack_is_amp_request', $is_amp_request );
	}

	/**
	 * Is the current theme an FSE/Site Editor theme.
	 *
	 * @since 1.4.0
	 * @since 1.4.22 Remove support for deprecated `gutenberg_is_fse_theme` function.
	 *
	 * @return bool True if the current theme is an FSE/Site Editor theme.
	 */
	public static function is_fse_theme() {
		$is_fse_theme = wp_is_block_theme();

		/**
		 * Returns true if the current theme is an FSE/Site Editor theme.
		 *
		 * @since 1.4.0
		 *
		 * @param boolean $is_fse_theme Is the theme an FSE theme.
		 */
		return apply_filters( 'jetpack_is_fse_theme', $is_fse_theme );
	}

	/**
	 * Check whether or the block being registered is a standalone block,
	 * running in a context outside of the Jetpack plugin.
	 *
	 * @since 1.3.0
	 *
	 * @return bool
	 */
	public static function is_standalone_block() {
		$is_standalone_block = ! class_exists( Jetpack_Gutenberg::class );

		/**
		 * Returns true if the block is not being registered within a Jetpack plugin context.
		 *
		 * @since 1.3.0
		 *
		 * @param boolean $is_standalone_block Is the block running standalone versus as part of the Jetpack plugin.
		 */
		return apply_filters( 'jetpack_is_standalone_block', $is_standalone_block );
	}
}