<?php
/**
 * Base registry.
 *
 * @package Extrova
 */

declare( strict_types=1 );

namespace Extrova\Registry;

defined( 'ABSPATH' ) || exit;

/**
 * Lazily built `slug => item` map passed once through a public `*_register_*` filter.
 * Built on first use (after `init`), so labels can be translated.
 *
 * @since 1.0.0
 */
abstract class AbstractRegistry {

	/**
	 * Resolved items.
	 *
	 * @var array<string, mixed>|null
	 */
	private ?array $items = null;

	/**
	 * Lite defaults.
	 *
	 * @return array<string, mixed>
	 */
	abstract protected function defaults(): array;

	/**
	 * Public filter name.
	 */
	abstract protected function filter_name(): string;

	/**
	 * Whether an item is valid for this registry.
	 *
	 * @param mixed $item Item.
	 */
	abstract protected function accepts( mixed $item ): bool;

	/**
	 * All items keyed by slug.
	 *
	 * @return array<string, mixed>
	 */
	public function all(): array {
		if ( null === $this->items ) {
			$items       = apply_filters( $this->filter_name(), $this->defaults() ); // phpcs:ignore WordPress.NamingConventions.PrefixAllGlobals.DynamicHooknameFound -- Every subclass returns a prefixed, documented hook name.
			$this->items = array();
			foreach ( (array) $items as $slug => $item ) {
				if ( is_string( $slug ) && '' !== $slug && $this->accepts( $item ) ) {
					$this->items[ $slug ] = $item;
				}
			}
		}
		return $this->items;
	}

	/**
	 * Whether a slug is registered.
	 *
	 * @param string $slug Slug.
	 */
	public function has( string $slug ): bool {
		return isset( $this->all()[ $slug ] );
	}

	/**
	 * Forces the registry to be rebuilt (tests).
	 */
	public function reset(): void {
		$this->items = null;
	}
}