<?php



final class WP_Interactivity_API_Directives_Processor extends WP_HTML_Tag_Processor {
	
	const TAGS_THAT_DONT_VISIT_CLOSER_TAG = array(
		'SCRIPT',
		'IFRAME',
		'NOEMBED',
		'NOFRAMES',
		'STYLE',
		'TEXTAREA',
		'TITLE',
		'XMP',
	);

	
	public function get_content_between_balanced_template_tags() {
		if ( 'TEMPLATE' !== $this->get_tag() ) {
			return null;
		}

		$positions = $this->get_after_opener_tag_and_before_closer_tag_positions();
		if ( ! $positions ) {
			return null;
		}
		list( $after_opener_tag, $before_closer_tag ) = $positions;

		return substr( $this->html, $after_opener_tag, $before_closer_tag - $after_opener_tag );
	}

	
	public function set_content_between_balanced_tags( string $new_content ): bool {
		$positions = $this->get_after_opener_tag_and_before_closer_tag_positions( true );
		if ( ! $positions ) {
			return false;
		}
		list( $after_opener_tag, $before_closer_tag ) = $positions;

		$this->lexical_updates[] = new WP_HTML_Text_Replacement(
			$after_opener_tag,
			$before_closer_tag - $after_opener_tag,
			esc_html( $new_content )
		);

		return true;
	}

	
	public function append_content_after_template_tag_closer( string $new_content ): bool {
		if ( empty( $new_content ) || 'TEMPLATE' !== $this->get_tag() || ! $this->is_tag_closer() ) {
			return false;
		}

		// Flushes any changes.
		$this->get_updated_html();

		$bookmark = 'append_content_after_template_tag_closer';
		$this->set_bookmark( $bookmark );
		$after_closing_tag = $this->bookmarks[ $bookmark ]->start + $this->bookmarks[ $bookmark ]->length;
		$this->release_bookmark( $bookmark );

		// Appends the new content.
		$this->lexical_updates[] = new WP_HTML_Text_Replacement( $after_closing_tag, 0, $new_content );

		return true;
	}

	
	private function get_after_opener_tag_and_before_closer_tag_positions( bool $rewind = false ) {
		// Flushes any changes.
		$this->get_updated_html();

		$bookmarks = $this->get_balanced_tag_bookmarks();
		if ( ! $bookmarks ) {
			return null;
		}
		list( $opener_tag, $closer_tag ) = $bookmarks;

		$after_opener_tag  = $this->bookmarks[ $opener_tag ]->start + $this->bookmarks[ $opener_tag ]->length;
		$before_closer_tag = $this->bookmarks[ $closer_tag ]->start;

		if ( $rewind ) {
			$this->seek( $opener_tag );
		}

		$this->release_bookmark( $opener_tag );
		$this->release_bookmark( $closer_tag );

		return array( $after_opener_tag, $before_closer_tag );
	}

	
	private function get_balanced_tag_bookmarks() {
		static $i   = 0;
		$opener_tag = 'opener_tag_of_balanced_tag_' . ++$i;

		$this->set_bookmark( $opener_tag );
		if ( ! $this->next_balanced_tag_closer_tag() ) {
			$this->release_bookmark( $opener_tag );
			return null;
		}

		$closer_tag = 'closer_tag_of_balanced_tag_' . ++$i;
		$this->set_bookmark( $closer_tag );

		return array( $opener_tag, $closer_tag );
	}

	
	public function skip_to_tag_closer(): bool {
		$depth    = 1;
		$tag_name = $this->get_tag();

		while ( $depth > 0 && $this->next_tag( array( 'tag_closers' => 'visit' ) ) ) {
			if ( ! $this->is_tag_closer() && $this->get_attribute_names_with_prefix( 'data-wp-' ) ) {
				/* translators: 1: SVG or MATH HTML tag. */
				$message = sprintf( __( 'Interactivity directives were detected inside an incompatible %1$s tag. These directives will be ignored in the server side render.' ), $tag_name );
				_doing_it_wrong( __METHOD__, $message, '6.6.0' );
			}
			if ( $this->get_tag() === $tag_name ) {
				if ( $this->has_self_closing_flag() ) {
					continue;
				}
				$depth += $this->is_tag_closer() ? -1 : 1;
			}
		}

		return 0 === $depth;
	}

	
	public function next_balanced_tag_closer_tag(): bool {
		$depth    = 0;
		$tag_name = $this->get_tag();

		if ( ! $this->has_and_visits_its_closer_tag() ) {
			return false;
		}

		while ( $this->next_tag(
			array(
				'tag_name'    => $tag_name,
				'tag_closers' => 'visit',
			)
		) ) {
			if ( ! $this->is_tag_closer() ) {
				++$depth;
				continue;
			}

			if ( 0 === $depth ) {
				return true;
			}

			--$depth;
		}

		return false;
	}

	
	public function has_and_visits_its_closer_tag(): bool {
		$tag_name = $this->get_tag();

		return null !== $tag_name && (
			! WP_HTML_Processor::is_void( $tag_name ) &&
			! in_array( $tag_name, self::TAGS_THAT_DONT_VISIT_CLOSER_TAG, true )
		);
	}
}