<?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;

	}

}