<?php

/**

 * Blocks API: WP_Block_Type_Registry class

 *

 * @package WordPress

 * @subpackage Blocks

 * @since 5.0.0

 */

/**

 * Core class used for interacting with block types.

 *

 * @since 5.0.0

 */

final class WP_Block_Type_Registry {

	/**

	 * Registered block types, as `$name => $instance` pairs.

	 *

	 * @since 5.0.0

	 * @var WP_Block_Type[]

	 */

	private $registered_block_types = array();

	/**

	 * Container for the main instance of the class.

	 *

	 * @since 5.0.0

	 * @var WP_Block_Type_Registry|null

	 */

	private static $instance = null;

	/**

	 * Registers a block type.

	 *

	 * @since 5.0.0

	 *

	 * @param string|WP_Block_Type $name Block type name including namespace, or alternatively

	 *                                   a complete WP_Block_Type instance. In case a WP_Block_Type

	 *                                   is provided, the $args parameter will be ignored.

	 * @return WP_Block_Type|false The registered block type on success, or false on failure.

	 */

	public function register( $name, $args = array() ) {

		$block_type = null;

		if ( $name instanceof WP_Block_Type ) {

			$block_type = $name;

			$name       = $block_type->name;

		}

		if ( ! is_string( $name ) ) {

			return false;

		}

		if ( preg_match( '/[A-Z]+/', $name ) ) {

			return false;

		}

		$name_matcher = '/^[a-z0-9-]+\/[a-z0-9-]+$/';

		if ( ! preg_match( $name_matcher, $name ) ) {

			return false;

		}

		if ( $this->is_registered( $name ) ) {

			return false;

		}

		if ( ! $block_type ) {

			$block_type = new WP_Block_Type( $name, $args );

		}

		$this->registered_block_types[ $name ] = $block_type;

		return $block_type;

	}

	/**

	 * Unregisters a block type.

	 *

	 * @since 5.0.0

	 *

	 * @param string|WP_Block_Type $name Block type name including namespace, or alternatively

	 *                                   a complete WP_Block_Type instance.

	 * @return WP_Block_Type|false The unregistered block type on success, or false on failure.

	 */

	public function unregister( $name ) {

		if ( $name instanceof WP_Block_Type ) {

			$name = $name->name;

		}

		if ( ! $this->is_registered( $name ) ) {

			return false;

		}

		$unregistered_block_type = $this->registered_block_types[ $name ];

		unset( $this->registered_block_types[ $name ] );

		return $unregistered_block_type;

	}

	/**

	 * Retrieves a registered block type.

	 *

	 * @since 5.0.0

	 *

	 * @param string $name Block type name including namespace.

	 * @return WP_Block_Type|null The registered block type, or null if it is not registered.

	 */

	public function get_registered( $name ) {

		if ( ! $this->is_registered( $name ) ) {

			return null;

		}

		return $this->registered_block_types[ $name ];

	}

	/**

	 * Retrieves all registered block types.

	 *

	 * @since 5.0.0

	 *

	 * @return WP_Block_Type[] Associative array of `$block_type_name => $block_type` pairs.

	 */

	public function get_all_registered() {

		return $this->registered_block_types;

	}

	/**

	 * Checks if a block type is registered.

	 *

	 * @since 5.0.0

	 *

	 * @param string $name Block type name including namespace.

	 * @return bool True if the block type is registered, false otherwise.

	 */

	public function is_registered( $name ) {

		return isset( $this->registered_block_types[ $name ] );

	}

	/**

	 * Utility method to retrieve the main instance of the class.

	 *

	 * The instance will be created if it does not exist yet.

	 *

	 * @since 5.0.0

	 *

	 * @return WP_Block_Type_Registry The main instance.

	 */

	public static function get_instance() {

		if ( null === self::$instance ) {

			self::$instance = new self();

		}

		return self::$instance;

	}

}