Enqueues a stylesheet for a specific block.

If the theme has opted-in to separate-styles loading,
then the stylesheet will be enqueued on-render,
otherwise when the block inits.

function wp_enqueue_block_style( $block_name, $args ) {
	$args = wp_parse_args(
		$args,
		array(
			'handle' => '',
			'src'    => '',
			'deps'   => array(),
			'ver'    => false,
			'media'  => 'all',
		)
	);

	/**
	 * Callback function to register and enqueue styles.
	 *
	 * @param string $content When the callback is used for the render_block filter,
	 *                        the content needs to be returned so the function parameter
	 *                        is to ensure the content exists.
	 * @return string Block content.
	 */
	$callback = static function( $content ) use ( $args ) {
		// Register the stylesheet.
		if ( ! empty( $args['src'] ) ) {
			wp_register_style( $args['handle'], $args['src'], $args['deps'], $args['ver'], $args['media'] );
		}

		// Add `path` data if provided.
		if ( isset( $args['path'] ) ) {
			wp_style_add_data( $args['handle'], 'path', $args['path'] );

			// Get the RTL file path.
			$rtl_file_path = str_replace( '.css', '-rtl.css', $args['path'] );

			// Add RTL stylesheet.
			if ( file_exists( $rtl_file_path ) ) {
				wp_style_add_data( $args['handle'], 'rtl', 'replace' );

				if ( is_rtl() ) {
					wp_style_add_data( $args['handle'], 'path', $rtl_file_path );
				}
			}
		}

		// Enqueue the stylesheet.
		wp_enqueue_style( $args['handle'] );

		return $content;
	};

	$hook = did_action( 'wp_enqueue_scripts' ) ? 'wp_footer' : 'wp_enqueue_scripts';
	if ( wp_should_load_separate_core_block_assets() ) {
		/**
		 * Callback function to register and enqueue styles.
		 *
		 * @param string $content The block content.
		 * @param array  $block   The full block, including name and attributes.
		 * @return string Block content.
		 */
		$callback_separate = static function( $content, $block ) use ( $block_name, $callback ) {
			if ( ! empty( $block['blockName'] ) && $block_name === $block['blockName'] ) {
				return $callback( $content );
			}
			return $content;
		};

		/*
		 * The filter's callback here is an anonymous function because
		 * using a named function in this case is not possible.
		 *
		 * The function cannot be unhooked, however, users are still able
		 * to dequeue the stylesheets registered/enqueued by the callback
		 * which is why in this case, using an anonymous function
		 * was deemed acceptable.
		 */
		add_filter( 'render_block', $callback_separate, 10, 2 );
		return;
	}

	/*
	 * The filter's callback here is an anonymous function because
	 * using a named function in this case is not possible.
	 *
	 * The function cannot be unhooked, however, users are still able
	 * to dequeue the stylesheets registered/enqueued by the callback
	 * which is why in this case, using an anonymous function
	 * was deemed acceptable.
	 */
	add_filter( $hook, $callback );

	// Enqueue assets in the editor.
	add_action( 'enqueue_block_assets', $callback );
}