block-template-utils.php

<?php
/**
 * Utilities used to fetch and create templates and template parts.
 *
 * @package WordPress
 * @since 5.8.0
 */

// Define constants for supported wp_template_part_area taxonomy.
if ( ! defined( 'WP_TEMPLATE_PART_AREA_HEADER' ) ) {
	define( 'WP_TEMPLATE_PART_AREA_HEADER', 'header' );
}
if ( ! defined( 'WP_TEMPLATE_PART_AREA_FOOTER' ) ) {
	define( 'WP_TEMPLATE_PART_AREA_FOOTER', 'footer' );
}
if ( ! defined( 'WP_TEMPLATE_PART_AREA_SIDEBAR' ) ) {
	define( 'WP_TEMPLATE_PART_AREA_SIDEBAR', 'sidebar' );
}
if ( ! defined( 'WP_TEMPLATE_PART_AREA_UNCATEGORIZED' ) ) {
	define( 'WP_TEMPLATE_PART_AREA_UNCATEGORIZED', 'uncategorized' );
}

/**
 * For backward compatibility reasons,
 * block themes might be using block-templates or block-template-parts,
 * this function ensures we fallback to these folders properly.
 *
 * @since 5.9.0
 *
 * @param string $theme_stylesheet The stylesheet. Default is to leverage the main theme root.
 *
 * @return string[] {
 *     Folder names used by block themes.
 *
 *     @type string $wp_template      Theme-relative directory name for block templates.
 *     @type string $wp_template_part Theme-relative directory name for block template parts.
 * }
 */
function get_block_theme_folders( $theme_stylesheet = null ) {
	$theme = wp_get_theme( (string) $theme_stylesheet );
	if ( ! $theme->exists() ) {
		// Return the default folders if the theme doesn't exist.
		return array(
			'wp_template'      => 'templates',
			'wp_template_part' => 'parts',
		);
	}
	return $theme->get_block_template_folders();
}

/**
 * Returns a filtered list of allowed area values for template parts.
 *
 * @since 5.9.0
 *
 * @return array[] The supported template part area values.
 */
function get_allowed_block_template_part_areas() {
	$default_area_definitions = array(
		array(
			'area'        => WP_TEMPLATE_PART_AREA_UNCATEGORIZED,
			'label'       => _x( 'General', 'template part area' ),
			'description' => __(
				'General templates often perform a specific role like displaying post content, and are not tied to any particular area.'
			),
			'icon'        => 'layout',
			'area_tag'    => 'div',
		),
		array(
			'area'        => WP_TEMPLATE_PART_AREA_HEADER,
			'label'       => _x( 'Header', 'template part area' ),
			'description' => __(
				'The Header template defines a page area that typically contains a title, logo, and main navigation.'
			),
			'icon'        => 'header',
			'area_tag'    => 'header',
		),
		array(
			'area'        => WP_TEMPLATE_PART_AREA_FOOTER,
			'label'       => _x( 'Footer', 'template part area' ),
			'description' => __(
				'The Footer template defines a page area that typically contains site credits, social links, or any other combination of blocks.'
			),
			'icon'        => 'footer',
			'area_tag'    => 'footer',
		),
	);

	/**
	 * Filters the list of allowed template part area values.
	 *
	 * @since 5.9.0
	 *
	 * @param array[] $default_area_definitions An array of supported area objects.
	 */
	return apply_filters( 'default_wp_template_part_areas', $default_area_definitions );
}


/**
 * Returns a filtered list of default template types, containing their
 * localized titles and descriptions.
 *
 * @since 5.9.0
 *
 * @return array[] The default template types.
 */
function get_default_block_template_types() {
	$default_template_types = array(
		'index'          => array(
			'title'       => _x( 'Index', 'Template name' ),
			'description' => __( 'Used as a fallback template for all pages when a more specific template is not defined.' ),
		),
		'home'           => array(
			'title'       => _x( 'Blog Home', 'Template name' ),
			'description' => __( 'Displays the latest posts as either the site homepage or as the "Posts page" as defined under reading settings. If it exists, the Front Page template overrides this template when posts are shown on the homepage.' ),
		),
		'front-page'     => array(
			'title'       => _x( 'Front Page', 'Template name' ),
			'description' => __( 'Displays your site\'s homepage, whether it is set to display latest posts or a static page. The Front Page template takes precedence over all templates.' ),
		),
		'singular'       => array(
			'title'       => _x( 'Single Entries', 'Template name' ),
			'description' => __( 'Displays any single entry, such as a post or a page. This template will serve as a fallback when a more specific template (e.g. Single Post, Page, or Attachment) cannot be found.' ),
		),
		'single'         => array(
			'title'       => _x( 'Single Posts', 'Template name' ),
			'description' => __( 'Displays single posts on your website unless a custom template has been applied to that post or a dedicated template exists.' ),
		),
		'page'           => array(
			'title'       => _x( 'Pages', 'Template name' ),
			'description' => __( 'Display all static pages unless a custom template has been applied or a dedicated template exists.' ),
		),
		'archive'        => array(
			'title'       => _x( 'All Archives', 'Template name' ),
			'description' => __( 'Displays any archive, including posts by a single author, category, tag, taxonomy, custom post type, and date. This template will serve as a fallback when more specific templates (e.g. Category or Tag) cannot be found.' ),
		),
		'author'         => array(
			'title'       => _x( 'Author Archives', 'Template name' ),
			'description' => __( 'Displays a single author\'s post archive. This template will serve as a fallback when a more specific template (e.g. Author: Admin) cannot be found.' ),
		),
		'category'       => array(
			'title'       => _x( 'Category Archives', 'Template name' ),
			'description' => __( 'Displays a post category archive. This template will serve as a fallback when a more specific template (e.g. Category: Recipes) cannot be found.' ),
		),
		'taxonomy'       => array(
			'title'       => _x( 'Taxonomy', 'Template name' ),
			'description' => __( 'Displays a custom taxonomy archive. Like categories and tags, taxonomies have terms which you use to classify things. For example: a taxonomy named "Art" can have multiple terms, such as "Modern" and "18th Century." This template will serve as a fallback when a more specific template (e.g. Taxonomy: Art) cannot be found.' ),
		),
		'date'           => array(
			'title'       => _x( 'Date Archives', 'Template name' ),
			'description' => __( 'Displays a post archive when a specific date is visited (e.g., example.com/2023/).' ),
		),
		'tag'            => array(
			'title'       => _x( 'Tag Archives', 'Template name' ),
			'description' => __( 'Displays a post tag archive. This template will serve as a fallback when a more specific template (e.g. Tag: Pizza) cannot be found.' ),
		),
		'attachment'     => array(
			'title'       => __( 'Attachment Pages' ),
			'description' => __( 'Displays when a visitor views the dedicated page that exists for any media attachment.' ),
		),
		'search'         => array(
			'title'       => _x( 'Search Results', 'Template name' ),
			'description' => __( 'Displays when a visitor performs a search on your website.' ),
		),
		'privacy-policy' => array(
			'title'       => __( 'Privacy Policy' ),
			'description' => __( 'Displays your site\'s Privacy Policy page.' ),
		),
		'404'            => array(
			'title'       => _x( 'Page: 404', 'Template name' ),
			'description' => __( 'Displays when a visitor views a non-existent page, such as a dead link or a mistyped URL.' ),
		),
	);

	/**
	 * Filters the list of template types.
	 *
	 * @since 5.9.0
	 *
	 * @param array[] $default_template_types An array of template types, formatted as [ slug => [ title, description ] ].
	 */
	return apply_filters( 'default_template_types', $default_template_types );
}

/**
 * Checks whether the input 'area' is a supported value.
 * Returns the input if supported, otherwise returns the 'uncategorized' value.
 *
 * @since 5.9.0
 * @access private
 *
 * @param string $type Template part area name.
 * @return string Input if supported, else the uncategorized value.
 */
function _filter_block_template_part_area( $type ) {
	$allowed_areas = array_map(
		static function ( $item ) {
			return $item['area'];
		},
		get_allowed_block_template_part_areas()
	);
	if ( in_array( $type, $allowed_areas, true ) ) {
		return $type;
	}

	$warning_message = sprintf(
		/* translators: %1$s: Template area type, %2$s: the uncategorized template area value. */
		__( '"%1$s" is not a supported wp_template_part area value and has been added as "%2$s".' ),
		$type,
		WP_TEMPLATE_PART_AREA_UNCATEGORIZED
	);
	trigger_error( $warning_message, E_USER_NOTICE );
	return WP_TEMPLATE_PART_AREA_UNCATEGORIZED;
}

/**
 * Finds all nested template part file paths in a theme's directory.
 *
 * @since 5.9.0
 * @access private
 *
 * @param string $base_directory The theme's file path.
 * @return string[] A list of paths to all template part files.
 */
function _get_block_templates_paths( $base_directory ) {
	$path_list = array();
	if ( file_exists( $base_directory ) ) {
		$nested_files      = new RecursiveIteratorIterator( new RecursiveDirectoryIterator( $base_directory ) );
		$nested_html_files = new RegexIterator( $nested_files, '/^.+\.html$/i', RecursiveRegexIterator::GET_MATCH );
		foreach ( $nested_html_files as $path => $file ) {
			$path_list[] = $path;
		}
	}
	return $path_list;
}

/**
 * Retrieves the template file from the theme for a given slug.
 *
 * @since 5.9.0
 * @access private
 *
 * @param string $template_type 'wp_template' or 'wp_template_part'.
 * @param string $slug          Template slug.
 * @return array|null {
 *    Array with template metadata if $template_type is one of 'wp_template' or 'wp_template_part'.
 *    null otherwise.
 *
 *    @type string   $slug      Template slug.
 *    @type string   $path      Template file path.
 *    @type string   $theme     Theme slug.
 *    @type string   $type      Template type.
 *    @type string   $area      Template area. Only for 'wp_template_part'.
 *    @type string   $title     Optional. Template title.
 *    @type string[] $postTypes Optional. List of post types that the template supports. Only for 'wp_template'.
 * }
 */
function _get_block_template_file( $template_type, $slug ) {
	if ( 'wp_template' !== $template_type && 'wp_template_part' !== $template_type ) {
		return null;
	}

	$themes = array(
		get_stylesheet() => get_stylesheet_directory(),
		get_template()   => get_template_directory(),
	);
	foreach ( $themes as $theme_slug => $theme_dir ) {
		$template_base_paths = get_block_theme_folders( $theme_slug );
		$file_path           = $theme_dir . '/' . $template_base_paths[ $template_type ] . '/' . $slug . '.html';
		if ( file_exists( $file_path ) ) {
			$new_template_item = array(
				'slug'  => $slug,
				'path'  => $file_path,
				'theme' => $theme_slug,
				'type'  => $template_type,
			);

			if ( 'wp_template_part' === $template_type ) {
				return _add_block_template_part_area_info( $new_template_item );
			}

			if ( 'wp_template' === $template_type ) {
				return _add_block_template_info( $new_template_item );
			}

			return $new_template_item;
		}
	}

	return null;
}

/**
 * Retrieves the template files from the theme.
 *
 * @since 5.9.0
 * @since 6.3.0 Added the `$query` parameter.
 * @access private
 *
 * @param string $template_type 'wp_template' or 'wp_template_part'.
 * @param array  $query {
 *     Arguments to retrieve templates. Optional, empty by default.
 *
 *     @type string[] $slug__in     List of slugs to include.
 *     @type string[] $slug__not_in List of slugs to skip.
 *     @type string   $area         A 'wp_template_part_area' taxonomy value to filter by (for 'wp_template_part' template type only).
 *     @type string   $post_type    Post type to get the templates for.
 * }
 *
 * @return array Template
 */
function _get_block_templates_files( $template_type, $query = array() ) {
	if ( 'wp_template' !== $template_type && 'wp_template_part' !== $template_type ) {
		return null;
	}

	// Prepare metadata from $query.
	$slugs_to_include = isset( $query['slug__in'] ) ? $query['slug__in'] : array();
	$slugs_to_skip    = isset( $query['slug__not_in'] ) ? $query['slug__not_in'] : array();
	$area             = isset( $query['area'] ) ? $query['area'] : null;
	$post_type        = isset( $query['post_type'] ) ? $query['post_type'] : '';

	$stylesheet = get_stylesheet();
	$template   = get_template();
	$themes     = array(
		$stylesheet => get_stylesheet_directory(),
	);
	// Add the parent theme if it's not the same as the current theme.
	if ( $stylesheet !== $template ) {
		$themes[ $template ] = get_template_directory();
	}
	$template_files = array();
	foreach ( $themes as $theme_slug => $theme_dir ) {
		$template_base_paths  = get_block_theme_folders( $theme_slug );
		$theme_template_files = _get_block_templates_paths( $theme_dir . '/' . $template_base_paths[ $template_type ] );
		foreach ( $theme_template_files as $template_file ) {
			$template_base_path = $template_base_paths[ $template_type ];
			$template_slug      = substr(
				$template_file,
				// Starting position of slug.
				strpos( $template_file, $template_base_path . DIRECTORY_SEPARATOR ) + 1 + strlen( $template_base_path ),
				// Subtract ending '.html'.
				-5
			);

			// Skip this item if its slug doesn't match any of the slugs to include.
			if ( ! empty( $slugs_to_include ) && ! in_array( $template_slug, $slugs_to_include, true ) ) {
				continue;
			}

			// Skip this item if its slug matches any of the slugs to skip.
			if ( ! empty( $slugs_to_skip ) && in_array( $template_slug, $slugs_to_skip, true ) ) {
				continue;
			}

			/*
			 * The child theme items (stylesheet) are processed before the parent theme's (template).
			 * If a child theme defines a template, prevent the parent template from being added to the list as well.
			 */
			if ( isset( $template_files[ $template_slug ] ) ) {
				continue;
			}

			$new_template_item = array(
				'slug'  => $template_slug,
				'path'  => $template_file,
				'theme' => $theme_slug,
				'type'  => $template_type,
			);

			if ( 'wp_template_part' === $template_type ) {
				$candidate = _add_block_template_part_area_info( $new_template_item );
				if ( ! isset( $area ) || ( isset( $area ) && $area === $candidate['area'] ) ) {
					$template_files[ $template_slug ] = $candidate;
				}
			}

			if ( 'wp_template' === $template_type ) {
				$candidate = _add_block_template_info( $new_template_item );
				if (
					! $post_type ||
					( $post_type && isset( $candidate['postTypes'] ) && in_array( $post_type, $candidate['postTypes'], true ) )
				) {
					$template_files[ $template_slug ] = $candidate;
				}
			}
		}
	}

	return array_values( $template_files );
}

/**
 * Attempts to add custom template information to the template item.
 *
 * @since 5.9.0
 * @access private
 *
 * @param array $template_item Template to add information to (requires 'slug' field).
 * @return array Template item.
 */
function _add_block_template_info( $template_item ) {
	if ( ! wp_theme_has_theme_json() ) {
		return $template_item;
	}

	$theme_data = wp_get_theme_data_custom_templates();
	if ( isset( $theme_data[ $template_item['slug'] ] ) ) {
		$template_item['title']     = $theme_data[ $template_item['slug'] ]['title'];
		$template_item['postTypes'] = $theme_data[ $template_item['slug'] ]['postTypes'];
	}

	return $template_item;
}

/**
 * Attempts to add the template part's area information to the input template.
 *
 * @since 5.9.0
 * @access private
 *
 * @param array $template_info Template to add information to (requires 'type' and 'slug' fields).
 * @return array Template info.
 */
function _add_block_template_part_area_info( $template_info ) {
	if ( wp_theme_has_theme_json() ) {
		$theme_data = wp_get_theme_data_template_parts();
	}

	if ( isset( $theme_data[ $template_info['slug'] ]['area'] ) ) {
		$template_info['title'] = $theme_data[ $template_info['slug'] ]['title'];
		$template_info['area']  = _filter_block_template_part_area( $theme_data[ $template_info['slug'] ]['area'] );
	} else {
		$template_info['area'] = WP_TEMPLATE_PART_AREA_UNCATEGORIZED;
	}

	return $template_info;
}

/**
 * Returns an array containing the references of
 * the passed blocks and their inner blocks.
 *
 * @since 5.9.0
 * @access private
 *
 * @param array $blocks array of blocks.
 * @return array block references to the passed blocks and their inner blocks.
 */
function _flatten_blocks( &$blocks ) {
	$all_blocks = array();
	$queue      = array();
	foreach ( $blocks as &$block ) {
		$queue[] = &$block;
	}

	while ( count( $queue ) > 0 ) {
		$block = &$queue[0];
		array_shift( $queue );
		$all_blocks[] = &$block;

		if ( ! empty( $block['innerBlocks'] ) ) {
			foreach ( $block['innerBlocks'] as &$inner_block ) {
				$queue[] = &$inner_block;
			}
		}
	}

	return $all_blocks;
}

/**
 * Injects the active theme's stylesheet as a `theme` attribute
 * into a given template part block.
 *
 * @since 6.4.0
 * @access private
 *
 * @param array $block a parsed block.
 * @return void
 */
function _inject_theme_attribute_in_template_part_block( &$block ) {
	if (
		'core/template-part' === $block['blockName'] &&
		! isset( $block['attrs']['theme'] )
	) {
		$block['attrs']['theme'] = get_stylesheet();
	}
}

/**
 * Removes the `theme` attribute from a given template part block.
 *
 * @since 6.4.0
 * @access private
 *
 * @param array $block a parsed block.
 * @return void
 */
function _remove_theme_attribute_from_template_part_block( &$block ) {
	if (
		'core/template-part' === $block['blockName'] &&
		isset( $block['attrs']['theme'] )
	) {
		unset( $block['attrs']['theme'] );
	}
}

/**
 * Builds a unified template object based on a theme file.
 *
 * @since 5.9.0
 * @since 6.3.0 Added `modified` property to template objects.
 * @access private
 *
 * @param array  $template_file Theme file.
 * @param string $template_type 'wp_template' or 'wp_template_part'.
 * @return WP_Block_Template Template.
 */
function _build_block_template_result_from_file( $template_file, $template_type ) {
	$default_template_types = get_default_block_template_types();
	$template_content       = file_get_contents( $template_file['path'] );
	$theme                  = get_stylesheet();

	$template                 = new WP_Block_Template();
	$template->id             = $theme . '//' . $template_file['slug'];
	$template->theme          = $theme;
	$template->slug           = $template_file['slug'];
	$template->source         = 'theme';
	$template->type           = $template_type;
	$template->title          = ! empty( $template_file['title'] ) ? $template_file['title'] : $template_file['slug'];
	$template->status         = 'publish';
	$template->has_theme_file = true;
	$template->is_custom      = true;
	$template->modified       = null;

	if ( 'wp_template' === $template_type && isset( $default_template_types[ $template_file['slug'] ] ) ) {
		$template->description = $default_template_types[ $template_file['slug'] ]['description'];
		$template->title       = $default_template_types[ $template_file['slug'] ]['title'];
		$template->is_custom   = false;
	}

	if ( 'wp_template' === $template_type && isset( $template_file['postTypes'] ) ) {
		$template->post_types = $template_file['postTypes'];
	}

	if ( 'wp_template_part' === $template_type && isset( $template_file['area'] ) ) {
		$template->area = $template_file['area'];
	}

	$before_block_visitor = '_inject_theme_attribute_in_template_part_block';
	$after_block_visitor  = null;
	$hooked_blocks        = get_hooked_blocks();
	if ( ! empty( $hooked_blocks ) || has_filter( 'hooked_block_types' ) ) {
		$before_block_visitor = make_before_block_visitor( $hooked_blocks, $template );
		$after_block_visitor  = make_after_block_visitor( $hooked_blocks, $template );
	}
	$blocks            = parse_blocks( $template_content );
	$template->content = traverse_and_serialize_blocks( $blocks, $before_block_visitor, $after_block_visitor );

	return $template;
}

/**
 * Builds the title and description of a post-specific template based on the underlying referenced post.
 *
 * Mutates the underlying template object.
 *
 * @since 6.1.0
 * @access private
 *
 * @param string            $post_type Post type, e.g. page, post, product.
 * @param string            $slug      Slug of the post, e.g. a-story-about-shoes.
 * @param WP_Block_Template $template  Template to mutate adding the description and title computed.
 * @return bool Returns true if the referenced post was found and false otherwise.
 */
function _wp_build_title_and_description_for_single_post_type_block_template( $post_type, $slug, WP_Block_Template $template ) {
	$post_type_object = get_post_type_object( $post_type );

	$default_args = array(
		'post_type'              => $post_type,
		'post_status'            => 'publish',
		'posts_per_page'         => 1,
		'update_post_meta_cache' => false,
		'update_post_term_cache' => false,
		'ignore_sticky_posts'    => true,
		'no_found_rows'          => true,
	);

	$args = array(
		'name' => $slug,
	);
	$args = wp_parse_args( $args, $default_args );

	$posts_query = new WP_Query( $args );

	if ( empty( $posts_query->posts ) ) {
		$template->title = sprintf(
			/* translators: Custom template title in the Site Editor referencing a post that was not found. 1: Post type singular name, 2: Post type slug. */
			__( 'Not found: %1$s (%2$s)' ),
			$post_type_object->labels->singular_name,
			$slug
		);

		return false;
	}

	$post_title = $posts_query->posts[0]->post_title;

	$template->title = sprintf(
		/* translators: Custom template title in the Site Editor. 1: Post type singular name, 2: Post title. */
		__( '%1$s: %2$s' ),
		$post_type_object->labels->singular_name,
		$post_title
	);

	$template->description = sprintf(
		/* translators: Custom template description in the Site Editor. %s: Post title. */
		__( 'Template for %s' ),
		$post_title
	);

	$args = array(
		'title' => $post_title,
	);
	$args = wp_parse_args( $args, $default_args );

	$posts_with_same_title_query = new WP_Query( $args );

	if ( count( $posts_with_same_title_query->posts ) > 1 ) {
		$template->title = sprintf(
			/* translators: Custom template title in the Site Editor. 1: Template title, 2: Post type slug. */
			__( '%1$s (%2$s)' ),
			$template->title,
			$slug
		);
	}

	return true;
}

/**
 * Builds the title and description of a taxonomy-specific template based on the underlying entity referenced.
 *
 * Mutates the underlying template object.
 *
 * @since 6.1.0
 * @access private
 *
 * @param string            $taxonomy Identifier of the taxonomy, e.g. category.
 * @param string            $slug     Slug of the term, e.g. shoes.
 * @param WP_Block_Template $template Template to mutate adding the description and title computed.
 * @return bool True if the term referenced was found and false otherwise.
 */
function _wp_build_title_and_description_for_taxonomy_block_template( $taxonomy, $slug, WP_Block_Template $template ) {
	$taxonomy_object = get_taxonomy( $taxonomy );

	$default_args = array(
		'taxonomy'               => $taxonomy,
		'hide_empty'             => false,
		'update_term_meta_cache' => false,
	);

	$term_query = new WP_Term_Query();

	$args = array(
		'number' => 1,
		'slug'   => $slug,
	);
	$args = wp_parse_args( $args, $default_args );

	$terms_query = $term_query->query( $args );

	if ( empty( $terms_query ) ) {
		$template->title = sprintf(
			/* translators: Custom template title in the Site Editor, referencing a taxonomy term that was not found. 1: Taxonomy singular name, 2: Term slug. */
			__( 'Not found: %1$s (%2$s)' ),
			$taxonomy_object->labels->singular_name,
			$slug
		);
		return false;
	}

	$term_title = $terms_query[0]->name;

	$template->title = sprintf(
		/* translators: Custom template title in the Site Editor. 1: Taxonomy singular name, 2: Term title. */
		__( '%1$s: %2$s' ),
		$taxonomy_object->labels->singular_name,
		$term_title
	);

	$template->description = sprintf(
		/* translators: Custom template description in the Site Editor. %s: Term title. */
		__( 'Template for %s' ),
		$term_title
	);

	$term_query = new WP_Term_Query();

	$args = array(
		'number' => 2,
		'name'   => $term_title,
	);
	$args = wp_parse_args( $args, $default_args );

	$terms_with_same_title_query = $term_query->query( $args );

	if ( count( $terms_with_same_title_query ) > 1 ) {
		$template->title = sprintf(
			/* translators: Custom template title in the Site Editor. 1: Template title, 2: Term slug. */
			__( '%1$s (%2$s)' ),
			$template->title,
			$slug
		);
	}

	return true;
}

/**
 * Builds a unified template object based a post Object.
 *
 * @since 5.9.0
 * @since 6.3.0 Added `modified` property to template objects.
 * @access private
 *
 * @param WP_Post $post Template post.
 * @return WP_Block_Template|WP_Error Template or error object.
 */
function _build_block_template_result_from_post( $post ) {
	$default_template_types = get_default_block_template_types();
	$terms                  = get_the_terms( $post, 'wp_theme' );

	if ( is_wp_error( $terms ) ) {
		return $terms;
	}

	if ( ! $terms ) {
		return new WP_Error( 'template_missing_theme', __( 'No theme is defined for this template.' ) );
	}

	$theme          = $terms[0]->name;
	$template_file  = _get_block_template_file( $post->post_type, $post->post_name );
	$has_theme_file = get_stylesheet() === $theme && null !== $template_file;

	$origin           = get_post_meta( $post->ID, 'origin', true );
	$is_wp_suggestion = get_post_meta( $post->ID, 'is_wp_suggestion', true );

	$template                 = new WP_Block_Template();
	$template->wp_id          = $post->ID;
	$template->id             = $theme . '//' . $post->post_name;
	$template->theme          = $theme;
	$template->content        = $post->post_content;
	$template->slug           = $post->post_name;
	$template->source         = 'custom';
	$template->origin         = ! empty( $origin ) ? $origin : null;
	$template->type           = $post->post_type;
	$template->description    = $post->post_excerpt;
	$template->title          = $post->post_title;
	$template->status         = $post->post_status;
	$template->has_theme_file = $has_theme_file;
	$template->is_custom      = empty( $is_wp_suggestion );
	$template->author         = $post->post_author;
	$template->modified       = $post->post_modified;

	if ( 'wp_template' === $post->post_type && $has_theme_file && isset( $template_file['postTypes'] ) ) {
		$template->post_types = $template_file['postTypes'];
	}

	if ( 'wp_template' === $post->post_type && isset( $default_template_types[ $template->slug ] ) ) {
		$template->is_custom = false;
	}

	if ( 'wp_template_part' === $post->post_type ) {
		$type_terms = get_the_terms( $post, 'wp_template_part_area' );
		if ( ! is_wp_error( $type_terms ) && false !== $type_terms ) {
			$template->area = $type_terms[0]->name;
		}
	}

	// Check for a block template without a description and title or with a title equal to the slug.
	if ( 'wp_template' === $post->post_type && empty( $template->description ) && ( empty( $template->title ) || $template->title === $template->slug ) ) {
		$matches = array();

		// Check for a block template for a single author, page, post, tag, category, custom post type, or custom taxonomy.
		if ( preg_match( '/(author|page|single|tag|category|taxonomy)-(.+)/', $template->slug, $matches ) ) {
			$type           = $matches[1];
			$slug_remaining = $matches[2];

			switch ( $type ) {
				case 'author':
					$nice_name = $slug_remaining;
					$users     = get_users(
						array(
							'capability'     => 'edit_posts',
							'search'         => $nice_name,
							'search_columns' => array( 'user_nicename' ),
							'fields'         => 'display_name',
						)
					);

					if ( empty( $users ) ) {
						$template->title = sprintf(
							/* translators: Custom template title in the Site Editor, referencing a deleted author. %s: Author nicename. */
							__( 'Deleted author: %s' ),
							$nice_name
						);
					} else {
						$author_name = $users[0];

						$template->title = sprintf(
							/* translators: Custom template title in the Site Editor. %s: Author name. */
							__( 'Author: %s' ),
							$author_name
						);

						$template->description = sprintf(
							/* translators: Custom template description in the Site Editor. %s: Author name. */
							__( 'Template for %s' ),
							$author_name
						);

						$users_with_same_name = get_users(
							array(
								'capability'     => 'edit_posts',
								'search'         => $author_name,
								'search_columns' => array( 'display_name' ),
								'fields'         => 'display_name',
							)
						);

						if ( count( $users_with_same_name ) > 1 ) {
							$template->title = sprintf(
								/* translators: Custom template title in the Site Editor. 1: Template title of an author template, 2: Author nicename. */
								__( '%1$s (%2$s)' ),
								$template->title,
								$nice_name
							);
						}
					}
					break;
				case 'page':
					_wp_build_title_and_description_for_single_post_type_block_template( 'page', $slug_remaining, $template );
					break;
				case 'single':
					$post_types = get_post_types();

					foreach ( $post_types as $post_type ) {
						$post_type_length = strlen( $post_type ) + 1;

						// If $slug_remaining starts with $post_type followed by a hyphen.
						if ( 0 === strncmp( $slug_remaining, $post_type . '-', $post_type_length ) ) {
							$slug  = substr( $slug_remaining, $post_type_length, strlen( $slug_remaining ) );
							$found = _wp_build_title_and_description_for_single_post_type_block_template( $post_type, $slug, $template );

							if ( $found ) {
								break;
							}
						}
					}
					break;
				case 'tag':
					_wp_build_title_and_description_for_taxonomy_block_template( 'post_tag', $slug_remaining, $template );
					break;
				case 'category':
					_wp_build_title_and_description_for_taxonomy_block_template( 'category', $slug_remaining, $template );
					break;
				case 'taxonomy':
					$taxonomies = get_taxonomies();

					foreach ( $taxonomies as $taxonomy ) {
						$taxonomy_length = strlen( $taxonomy ) + 1;

						// If $slug_remaining starts with $taxonomy followed by a hyphen.
						if ( 0 === strncmp( $slug_remaining, $taxonomy . '-', $taxonomy_length ) ) {
							$slug  = substr( $slug_remaining, $taxonomy_length, strlen( $slug_remaining ) );
							$found = _wp_build_title_and_description_for_taxonomy_block_template( $taxonomy, $slug, $template );

							if ( $found ) {
								break;
							}
						}
					}
					break;
			}
		}
	}

	return $template;
}

/**
 * Retrieves a list of unified template objects based on a query.
 *
 * @since 5.8.0
 *
 * @param array  $query {
 *     Optional. Arguments to retrieve templates.
 *
 *     @type string[] $slug__in  List of slugs to include.
 *     @type int      $wp_id     Post ID of customized template.
 *     @type string   $area      A 'wp_template_part_area' taxonomy value to filter by (for 'wp_template_part' template type only).
 *     @type string   $post_type Post type to get the templates for.
 * }
 * @param string $template_type 'wp_template' or 'wp_template_part'.
 * @return WP_Block_Template[] Array of block templates.
 */
function get_block_templates( $query = array(), $template_type = 'wp_template' ) {
	/**
	 * Filters the block templates array before the query takes place.
	 *
	 * Return a non-null value to bypass the WordPress queries.
	 *
	 * @since 5.9.0
	 *
	 * @param WP_Block_Template[]|null $block_templates Return an array of block templates to short-circuit the default query,
	 *                                                  or null to allow WP to run its normal queries.
	 * @param array  $query {
	 *     Arguments to retrieve templates. All arguments are optional.
	 *
	 *     @type string[] $slug__in  List of slugs to include.
	 *     @type int      $wp_id     Post ID of customized template.
	 *     @type string   $area      A 'wp_template_part_area' taxonomy value to filter by (for 'wp_template_part' template type only).
	 *     @type string   $post_type Post type to get the templates for.
	 * }
	 * @param string $template_type 'wp_template' or 'wp_template_part'.
	 */
	$templates = apply_filters( 'pre_get_block_templates', null, $query, $template_type );
	if ( ! is_null( $templates ) ) {
		return $templates;
	}

	$post_type     = isset( $query['post_type'] ) ? $query['post_type'] : '';
	$wp_query_args = array(
		'post_status'         => array( 'auto-draft', 'draft', 'publish' ),
		'post_type'           => $template_type,
		'posts_per_page'      => -1,
		'no_found_rows'       => true,
		'lazy_load_term_meta' => false,
		'tax_query'           => array(
			array(
				'taxonomy' => 'wp_theme',
				'field'    => 'name',
				'terms'    => get_stylesheet(),
			),
		),
	);

	if ( 'wp_template_part' === $template_type && isset( $query['area'] ) ) {
		$wp_query_args['tax_query'][]           = array(
			'taxonomy' => 'wp_template_part_area',
			'field'    => 'name',
			'terms'    => $query['area'],
		);
		$wp_query_args['tax_query']['relation'] = 'AND';
	}

	if ( ! empty( $query['slug__in'] ) ) {
		$wp_query_args['post_name__in']  = $query['slug__in'];
		$wp_query_args['posts_per_page'] = count( array_unique( $query['slug__in'] ) );
	}

	// This is only needed for the regular templates/template parts post type listing and editor.
	if ( isset( $query['wp_id'] ) ) {
		$wp_query_args['p'] = $query['wp_id'];
	} else {
		$wp_query_args['post_status'] = 'publish';
	}

	$template_query = new WP_Query( $wp_query_args );
	$query_result   = array();
	foreach ( $template_query->posts as $post ) {
		$template = _build_block_template_result_from_post( $post );

		if ( is_wp_error( $template ) ) {
			continue;
		}

		if ( $post_type && ! $template->is_custom ) {
			continue;
		}

		if (
			$post_type &&
			isset( $template->post_types ) &&
			! in_array( $post_type, $template->post_types, true )
		) {
			continue;
		}

		$query_result[] = $template;
	}

	if ( ! isset( $query['wp_id'] ) ) {
		/*
		 * If the query has found some use templates, those have priority
		 * over the theme-provided ones, so we skip querying and building them.
		 */
		$query['slug__not_in'] = wp_list_pluck( $query_result, 'slug' );
		$template_files        = _get_block_templates_files( $template_type, $query );
		foreach ( $template_files as $template_file ) {
			$query_result[] = _build_block_template_result_from_file( $template_file, $template_type );
		}
	}

	/**
	 * Filters the array of queried block templates array after they've been fetched.
	 *
	 * @since 5.9.0
	 *
	 * @param WP_Block_Template[] $query_result Array of found block templates.
	 * @param array               $query {
	 *     Arguments to retrieve templates. All arguments are optional.
	 *
	 *     @type string[] $slug__in  List of slugs to include.
	 *     @type int      $wp_id     Post ID of customized template.
	 *     @type string   $area      A 'wp_template_part_area' taxonomy value to filter by (for 'wp_template_part' template type only).
	 *     @type string   $post_type Post type to get the templates for.
	 * }
	 * @param string              $template_type wp_template or wp_template_part.
	 */
	return apply_filters( 'get_block_templates', $query_result, $query, $template_type );
}

/**
 * Retrieves a single unified template object using its id.
 *
 * @since 5.8.0
 *
 * @param string $id            Template unique identifier (example: 'theme_slug//template_slug').
 * @param string $template_type Optional. Template type: 'wp_template' or 'wp_template_part'.
 *                              Default 'wp_template'.
 * @return WP_Block_Template|null Template.
 */
function get_block_template( $id, $template_type = 'wp_template' ) {
	/**
	 * Filters the block template object before the query takes place.
	 *
	 * Return a non-null value to bypass the WordPress queries.
	 *
	 * @since 5.9.0
	 *
	 * @param WP_Block_Template|null $block_template Return block template object to short-circuit the default query,
	 *                                               or null to allow WP to run its normal queries.
	 * @param string                 $id             Template unique identifier (example: 'theme_slug//template_slug').
	 * @param string                 $template_type  Template type: 'wp_template' or 'wp_template_part'.
	 */
	$block_template = apply_filters( 'pre_get_block_template', null, $id, $template_type );
	if ( ! is_null( $block_template ) ) {
		return $block_template;
	}

	$parts = explode( '//', $id, 2 );
	if ( count( $parts ) < 2 ) {
		return null;
	}
	list( $theme, $slug ) = $parts;
	$wp_query_args        = array(
		'post_name__in'  => array( $slug ),
		'post_type'      => $template_type,
		'post_status'    => array( 'auto-draft', 'draft', 'publish', 'trash' ),
		'posts_per_page' => 1,
		'no_found_rows'  => true,
		'tax_query'      => array(
			array(
				'taxonomy' => 'wp_theme',
				'field'    => 'name',
				'terms'    => $theme,
			),
		),
	);
	$template_query       = new WP_Query( $wp_query_args );
	$posts                = $template_query->posts;

	if ( count( $posts ) > 0 ) {
		$template = _build_block_template_result_from_post( $posts[0] );

		if ( ! is_wp_error( $template ) ) {
			return $template;
		}
	}

	$block_template = get_block_file_template( $id, $template_type );

	/**
	 * Filters the queried block template object after it's been fetched.
	 *
	 * @since 5.9.0
	 *
	 * @param WP_Block_Template|null $block_template The found block template, or null if there isn't one.
	 * @param string                 $id             Template unique identifier (example: 'theme_slug//template_slug').
	 * @param array                  $template_type  Template type: 'wp_template' or 'wp_template_part'.
	 */
	return apply_filters( 'get_block_template', $block_template, $id, $template_type );
}

/**
 * Retrieves a unified template object based on a theme file.
 *
 * This is a fallback of get_block_template(), used when no templates are found in the database.
 *
 * @since 5.9.0
 *
 * @param string $id            Template unique identifier (example: 'theme_slug//template_slug').
 * @param string $template_type Optional. Template type: 'wp_template' or 'wp_template_part'.
 *                              Default 'wp_template'.
 * @return WP_Block_Template|null The found block template, or null if there isn't one.
 */
function get_block_file_template( $id, $template_type = 'wp_template' ) {
	/**
	 * Filters the block template object before the theme file discovery takes place.
	 *
	 * Return a non-null value to bypass the WordPress theme file discovery.
	 *
	 * @since 5.9.0
	 *
	 * @param WP_Block_Template|null $block_template Return block template object to short-circuit the default query,
	 *                                               or null to allow WP to run its normal queries.
	 * @param string                 $id             Template unique identifier (example: 'theme_slug//template_slug').
	 * @param string                 $template_type  Template type: 'wp_template' or 'wp_template_part'.
	 */
	$block_template = apply_filters( 'pre_get_block_file_template', null, $id, $template_type );
	if ( ! is_null( $block_template ) ) {
		return $block_template;
	}

	$parts = explode( '//', $id, 2 );
	if ( count( $parts ) < 2 ) {
		/** This filter is documented in wp-includes/block-template-utils.php */
		return apply_filters( 'get_block_file_template', null, $id, $template_type );
	}
	list( $theme, $slug ) = $parts;

	if ( get_stylesheet() !== $theme ) {
		/** This filter is documented in wp-includes/block-template-utils.php */
		return apply_filters( 'get_block_file_template', null, $id, $template_type );
	}

	$template_file = _get_block_template_file( $template_type, $slug );
	if ( null === $template_file ) {
		/** This filter is documented in wp-includes/block-template-utils.php */
		return apply_filters( 'get_block_file_template', null, $id, $template_type );
	}

	$block_template = _build_block_template_result_from_file( $template_file, $template_type );

	/**
	 * Filters the block template object after it has been (potentially) fetched from the theme file.
	 *
	 * @since 5.9.0
	 *
	 * @param WP_Block_Template|null $block_template The found block template, or null if there is none.
	 * @param string                 $id             Template unique identifier (example: 'theme_slug//template_slug').
	 * @param string                 $template_type  Template type: 'wp_template' or 'wp_template_part'.
	 */
	return apply_filters( 'get_block_file_template', $block_template, $id, $template_type );
}

/**
 * Prints a block template part.
 *
 * @since 5.9.0
 *
 * @param string $part The block template part to print. Use "header" or "footer".
 */
function block_template_part( $part ) {
	$template_part = get_block_template( get_stylesheet() . '//' . $part, 'wp_template_part' );
	if ( ! $template_part || empty( $template_part->content ) ) {
		return;
	}
	echo do_blocks( $template_part->content );
}

/**
 * Prints the header block template part.
 *
 * @since 5.9.0
 */
function block_header_area() {
	block_template_part( 'header' );
}

/**
 * Prints the footer block template part.
 *
 * @since 5.9.0
 */
function block_footer_area() {
	block_template_part( 'footer' );
}

/**
 * Determines whether a theme directory should be ignored during export.
 *
 * @since 6.0.0
 *
 * @param string $path The path of the file in the theme.
 * @return Bool Whether this file is in an ignored directory.
 */
function wp_is_theme_directory_ignored( $path ) {
	$directories_to_ignore = array( '.DS_Store', '.svn', '.git', '.hg', '.bzr', 'node_modules', 'vendor' );

	foreach ( $directories_to_ignore as $directory ) {
		if ( str_starts_with( $path, $directory ) ) {
			return true;
		}
	}

	return false;
}

/**
 * Creates an export of the current templates and
 * template parts from the site editor at the
 * specified path in a ZIP file.
 *
 * @since 5.9.0
 * @since 6.0.0 Adds the whole theme to the export archive.
 *
 * @global string $wp_version The WordPress version string.
 *
 * @return WP_Error|string Path of the ZIP file or error on failure.
 */
function wp_generate_block_templates_export_file() {
	global $wp_version;

	if ( ! class_exists( 'ZipArchive' ) ) {
		return new WP_Error( 'missing_zip_package', __( 'Zip Export not supported.' ) );
	}

	$obscura    = wp_generate_password( 12, false, false );
	$theme_name = basename( get_stylesheet() );
	$filename   = get_temp_dir() . $theme_name . $obscura . '.zip';

	$zip = new ZipArchive();
	if ( true !== $zip->open( $filename, ZipArchive::CREATE | ZipArchive::OVERWRITE ) ) {
		return new WP_Error( 'unable_to_create_zip', __( 'Unable to open export file (archive) for writing.' ) );
	}

	$zip->addEmptyDir( 'templates' );
	$zip->addEmptyDir( 'parts' );

	// Get path of the theme.
	$theme_path = wp_normalize_path( get_stylesheet_directory() );

	// Create recursive directory iterator.
	$theme_files = new RecursiveIteratorIterator(
		new RecursiveDirectoryIterator( $theme_path ),
		RecursiveIteratorIterator::LEAVES_ONLY
	);

	// Make a copy of the current theme.
	foreach ( $theme_files as $file ) {
		// Skip directories as they are added automatically.
		if ( ! $file->isDir() ) {
			// Get real and relative path for current file.
			$file_path     = wp_normalize_path( $file );
			$relative_path = substr( $file_path, strlen( $theme_path ) + 1 );

			if ( ! wp_is_theme_directory_ignored( $relative_path ) ) {
				$zip->addFile( $file_path, $relative_path );
			}
		}
	}

	// Load templates into the zip file.
	$templates = get_block_templates();
	foreach ( $templates as $template ) {
		$template->content = traverse_and_serialize_blocks(
			parse_blocks( $template->content ),
			'_remove_theme_attribute_from_template_part_block'
		);

		$zip->addFromString(
			'templates/' . $template->slug . '.html',
			$template->content
		);
	}

	// Load template parts into the zip file.
	$template_parts = get_block_templates( array(), 'wp_template_part' );
	foreach ( $template_parts as $template_part ) {
		$zip->addFromString(
			'parts/' . $template_part->slug . '.html',
			$template_part->content
		);
	}

	// Load theme.json into the zip file.
	$tree = WP_Theme_JSON_Resolver::get_theme_data( array(), array( 'with_supports' => false ) );
	// Merge with user data.
	$tree->merge( WP_Theme_JSON_Resolver::get_user_data() );

	$theme_json_raw = $tree->get_data();
	// If a version is defined, add a schema.
	if ( $theme_json_raw['version'] ) {
		$theme_json_version = 'wp/' . substr( $wp_version, 0, 3 );
		$schema             = array( '$schema' => 'https://schemas.wp.org/' . $theme_json_version . '/theme.json' );
		$theme_json_raw     = array_merge( $schema, $theme_json_raw );
	}

	// Convert to a string.
	$theme_json_encoded = wp_json_encode( $theme_json_raw, JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES | JSON_UNESCAPED_UNICODE );

	// Replace 4 spaces with a tab.
	$theme_json_tabbed = preg_replace( '~(?:^|\G)\h{4}~m', "\t", $theme_json_encoded );

	// Add the theme.json file to the zip.
	$zip->addFromString(
		'theme.json',
		$theme_json_tabbed
	);

	// Save changes to the zip file.
	$zip->close();

	return $filename;
}

/**
 * Gets the template hierarchy for the given template slug to be created.
 *
 * Note: Always add `index` as the last fallback template.
 *
 * @since 6.1.0
 *
 * @param string  $slug           The template slug to be created.
 * @param boolean $is_custom      Optional. Indicates if a template is custom or
 *                                part of the template hierarchy. Default false.
 * @param string $template_prefix Optional. The template prefix for the created template.
 *                                Used to extract the main template type, e.g.
 *                                in `taxonomy-books` the `taxonomy` is extracted.
 *                                Default empty string.
 * @return string[] The template hierarchy.
 */
function get_template_hierarchy( $slug, $is_custom = false, $template_prefix = '' ) {
	if ( 'index' === $slug ) {
		return array( 'index' );
	}
	if ( $is_custom ) {
		return array( 'page', 'singular', 'index' );
	}
	if ( 'front-page' === $slug ) {
		return array( 'front-page', 'home', 'index' );
	}

	$matches = array();

	$template_hierarchy = array( $slug );
	// Most default templates don't have `$template_prefix` assigned.
	if ( ! empty( $template_prefix ) ) {
		list( $type ) = explode( '-', $template_prefix );
		// We need these checks because we always add the `$slug` above.
		if ( ! in_array( $template_prefix, array( $slug, $type ), true ) ) {
			$template_hierarchy[] = $template_prefix;
		}
		if ( $slug !== $type ) {
			$template_hierarchy[] = $type;
		}
	} elseif ( preg_match( '/^(author|category|archive|tag|page)-.+$/', $slug, $matches ) ) {
		$template_hierarchy[] = $matches[1];
	} elseif ( preg_match( '/^(taxonomy|single)-(.+)$/', $slug, $matches ) ) {
		$type           = $matches[1];
		$slug_remaining = $matches[2];

		$items = 'single' === $type ? get_post_types() : get_taxonomies();
		foreach ( $items as $item ) {
			if ( ! str_starts_with( $slug_remaining, $item ) ) {
					continue;
			}

			// If $slug_remaining is equal to $post_type or $taxonomy we have
			// the single-$post_type template or the taxonomy-$taxonomy template.
			if ( $slug_remaining === $item ) {
				$template_hierarchy[] = $type;
				break;
			}

			// If $slug_remaining is single-$post_type-$slug template.
			if ( strlen( $slug_remaining ) > strlen( $item ) + 1 ) {
				$template_hierarchy[] = "$type-$item";
				$template_hierarchy[] = $type;
				break;
			}
		}
	}
	// Handle `archive` template.
	if (
		str_starts_with( $slug, 'author' ) ||
		str_starts_with( $slug, 'taxonomy' ) ||
		str_starts_with( $slug, 'category' ) ||
		str_starts_with( $slug, 'tag' ) ||
		'date' === $slug
	) {
		$template_hierarchy[] = 'archive';
	}
	// Handle `single` template.
	if ( 'attachment' === $slug ) {
		$template_hierarchy[] = 'single';
	}
	// Handle `singular` template.
	if (
		str_starts_with( $slug, 'single' ) ||
		str_starts_with( $slug, 'page' ) ||
		'attachment' === $slug
	) {
		$template_hierarchy[] = 'singular';
	}
	$template_hierarchy[] = 'index';
	return $template_hierarchy;
}