smuuf/primi

<?php

declare(strict_types=1);

namespace Smuuf\Primi\Helpers;

use \Smuuf\Primi\Ex\EngineInternalError;
use \Smuuf\Primi\Values\TypeValue;
use \Smuuf\Primi\Values\AbstractValue;
use \Smuuf\Primi\Values\InstanceValue;

abstract class TypeResolver {

    /**
     * Some classes used for representing Primi objects have "unfriendly"
     * values of their "TYPE" class constants.
     *
     * If we, for example, want to display error message about wrong type
     * of argument passed into a native PHP function (called from Primi) when
     * a basic "AbstractValue" class is typehinted (because that PHP class
     * is a base class for other PHP classes representing Primi objects), we
     * want to display "object" instead of AbstractValue's "__undefined__" TYPE.
     */
    private const OVERRIDE_TYPES = [
        AbstractValue::class => 'object',
        InstanceValue::class => 'object',
    ];

    /**
     * Return type name for a Primi object or for PHP class which represents
     * object of a basic native type (e.g. `StringValue`).
     *
     * @param class-string|AbstractValue $type
     */
    public static function resolve($type): string {

        if (\is_string($type)) {

            // Return Primi type name based on passed PHP class name
            // representing a basic native Primi object.

            // Normalize PHP class name to a form without leading backslash.
            $type = \ltrim($type, '\\');
            if (isset(self::OVERRIDE_TYPES[$type])) {
                return self::OVERRIDE_TYPES[$type];
            }

            if (!\is_subclass_of($type, AbstractValue::class, \true)) {
                throw new EngineInternalError(
                    "Unable to resolve Primi type name for PHP class '$type'");
            }

            return $type::TYPE;

        } elseif ($type instanceof TypeValue) {

            // Return Primi type name based on an actual Primi object (passed
            // as PHP object representing a Primi object).
            return $type->getName();

        }

        $type = \get_debug_type($type);
        throw new EngineInternalError(
            "Unable to resolve Primi type name from PHP value '$type'");

    }

}