<?php
/**
* Templates registry functions.
*
* @package WordPress
* @since 6.7.0
*/

/**
* Core class used for interacting with templates.
*
* @since 6.7.0
*/
final class WP_Block_Templates_Registry {
/**
* Registered templates, as `$name => $instance` pairs.
*
* @since 6.7.0
* @var WP_Block_Template[] $registered_block_templates Registered templates.
*/
private $registered_templates = array();

/**
* Container for the main instance of the class.
*
* @since 6.7.0
* @var WP_Block_Templates_Registry|null
*/
private static $instance = null;

/**
* Registers a template.
*
* @since 6.7.0
*
* @param string $template_name Template name including namespace.
* @param array $args Optional. Array of template arguments.
* @return WP_Block_Template|WP_Error The registered template on success, or WP_Error on failure.
*/
public function register( $template_name, $args = array() ) {

$template = null;

$error_message = '';
$error_code = '';

if ( ! is_string( $template_name ) ) {
$error_message = __( 'Template names must be strings.' );
$error_code = 'template_name_no_string';
} elseif ( preg_match( '/[A-Z]+/', $template_name ) ) {
$error_message = __( 'Template names must not contain uppercase characters.' );
$error_code = 'template_name_no_uppercase';
} elseif ( ! preg_match( '/^[a-z0-9_\-]+\/\/[a-z0-9_\-]+$/', $template_name ) ) {
$error_message = __( 'Template names must contain a namespace prefix. Example: my-plugin//my-custom-template' );
$error_code = 'template_no_prefix';
} elseif ( $this->is_registered( $template_name ) ) {
/* translators: %s: Template name. */
$error_message = sprintf( __( 'Template "%s" is already registered.' ), $template_name );
$error_code = 'template_already_registered';
}

if ( $error_message ) {
_doing_it_wrong(
__METHOD__,
$error_message,
'6.7.0'
);
return new WP_Error( $error_code, $error_message );
}

if ( ! $template ) {
$theme_name = get_stylesheet();
list( $plugin, $slug ) = explode( '//', $template_name );
$default_template_types = get_default_block_template_types();

$template = new WP_Block_Template();
$template->id = $theme_name . '//' . $slug;
$template->theme = $theme_name;
$template->plugin = $plugin;
$template->author = null;
$template->content = isset( $args['content'] ) ? $args['content'] : '';
$template->source = 'plugin';
$template->slug = $slug;
$template->type = 'wp_template';
$template->title = isset( $args['title'] ) ? $args['title'] : $template_name;
$template->description = isset( $args['description'] ) ? $args['description'] : '';
$template->status = 'publish';
$template->origin = 'plugin';
$template->is_custom = ! isset( $default_template_types[ $template_name ] );
$template->post_types = isset( $args['post_types'] ) ? $args['post_types'] : array();
}

$this->registered_templates[ $template_name ] = $template;

return $template;
}

/**
* Retrieves all registered templates.
*
* @since 6.7.0
*
* @return WP_Block_Template[] Associative array of `$template_name => $template` pairs.
*/
public function get_all_registered() {
return $this->registered_templates;
}

/**
* Retrieves a registered template by its name.
*
* @since 6.7.0
*
* @param string $template_name Template name including namespace.
* @return WP_Block_Template|null The registered template, or null if it is not registered.
*/
public function get_registered( $template_name ) {
if ( ! $this->is_registered( $template_name ) ) {
return null;
}

return $this->registered_templates[ $template_name ];
}

/**
* Retrieves a registered template by its slug.
*
* @since 6.7.0
*
* @param string $template_slug Slug of the template.
* @return WP_Block_Template|null The registered template, or null if it is not registered.
*/
public function get_by_slug( $template_slug ) {
$all_templates = $this->get_all_registered();

if ( ! $all_templates ) {
return null;
}

foreach ( $all_templates as $template ) {
if ( $template->slug === $template_slug ) {
return $template;
}
}

return null;
}

/**
* Retrieves registered templates matching a query.
*
* @since 6.7.0
*
* @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 $post_type Post type to get the templates for.
* }
* @return WP_Block_Template[] Associative array of `$template_name => $template` pairs.
*/
public function get_by_query( $query = array() ) {
$all_templates = $this->get_all_registered();

if ( ! $all_templates ) {
return array();
}

$query = wp_parse_args(
$query,
array(
'slug__in' => array(),
'slug__not_in' => array(),
'post_type' => '',
)
);
$slugs_to_include = $query['slug__in'];
$slugs_to_skip = $query['slug__not_in'];
$post_type = $query['post_type'];

$matching_templates = array();
foreach ( $all_templates as $template_name => $template ) {
if ( $slugs_to_include && ! in_array( $template->slug, $slugs_to_include, true ) ) {
continue;
}

if ( $slugs_to_skip && in_array( $template->slug, $slugs_to_skip, true ) ) {
continue;
}

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

$matching_templates[ $template_name ] = $template;
}

return $matching_templates;
}

/**
* Checks if a template is registered.
*
* @since 6.7.0
*
* @param string $template_name Template name.
* @return bool True if the template is registered, false otherwise.
*/
public function is_registered( $template_name ) {
return isset( $this->registered_templates[ $template_name ] );
}

/**
* Unregisters a template.
*
* @since 6.7.0
*
* @param string $template_name Template name including namespace.
* @return WP_Block_Template|WP_Error The unregistered template on success, or WP_Error on failure.
*/
public function unregister( $template_name ) {
if ( ! $this->is_registered( $template_name ) ) {
_doing_it_wrong(
__METHOD__,
/* translators: %s: Template name. */
sprintf( __( 'Template "%s" is not registered.' ), $template_name ),
'6.7.0'
);
/* translators: %s: Template name. */
return new WP_Error( 'template_not_registered', __( 'Template "%s" is not registered.' ) );
}

$unregistered_template = $this->registered_templates[ $template_name ];
unset( $this->registered_templates[ $template_name ] );

return $unregistered_template;
}

/**
* Utility method to retrieve the main instance of the class.
*
* The instance will be created if it does not exist yet.
*
* @since 6.7.0
*
* @return WP_Block_Templates_Registry The main instance.
*/
public static function get_instance() {
if ( null === self::$instance ) {
self::$instance = new self();
}

return self::$instance;
}
}