<?php
/**
 * Core service container.
 *
 * @package ABCTransferSmartOrders
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

class ABCT_Core_Container {
	/**
	 * Registered factories.
	 *
	 * @var array<string,callable>
	 */
	private $factories = array();

	/**
	 * Resolved instances.
	 *
	 * @var array<string,mixed>
	 */
	private $instances = array();

	/**
	 * Register factory.
	 *
	 * @param string   $id Service ID.
	 * @param callable $factory Factory callback.
	 * @return void
	 */
	public function set( $id, $factory ) {
		$this->factories[ (string) $id ] = $factory;
	}

	/**
	 * Resolve service.
	 *
	 * @param string $id Service ID.
	 * @return mixed|null
	 */
	public function get( $id ) {
		$key = (string) $id;
		if ( array_key_exists( $key, $this->instances ) ) {
			return $this->instances[ $key ];
		}

		if ( ! isset( $this->factories[ $key ] ) ) {
			return null;
		}

		$this->instances[ $key ] = call_user_func( $this->factories[ $key ], $this );
		return $this->instances[ $key ];
	}
}