<?php

declare(strict_types=1);

namespace GraphQL\Type\Definition;

use Exception;
use GraphQL\Error\Error;
use GraphQL\Language\AST\IntValueNode;
use GraphQL\Language\AST\Node;
use GraphQL\Language\AST\StringValueNode;
use GraphQL\Utils\Utils;
use function is_int;
use function is_object;
use function is_scalar;
use function is_string;
use function method_exists;

class IDType extends ScalarType
{
    /** @var string */
    public $name = 'ID';

    /** @var string */
    public $description =
        'The `ID` scalar type represents a unique identifier, often used to
refetch an object or as key for a cache. The ID type appears in a JSON
response as a String; however, it is not intended to be human-readable.
When expected as an input type, any string (such as `"4"`) or integer
(such as `4`) input value will be accepted as an ID.';

    /**
     * @param mixed $value
     *
     * @return string
     *
     * @throws Error
     */
    public function serialize($value)
    {
        if ($value === true) {
            return 'true';
        }
        if ($value === false) {
            return 'false';
        }
        if ($value === null) {
            return 'null';
        }
        if (! is_scalar($value) && (! is_object($value) || ! method_exists($value, '__toString'))) {
            throw new Error('ID type cannot represent non scalar value: ' . Utils::printSafe($value));
        }

        return (string) $value;
    }

    /**
     * @param mixed $value
     *
     * @return string
     *
     * @throws Error
     */
    public function parseValue($value)
    {
        if (is_string($value) || is_int($value)) {
            return (string) $value;
        }

        throw new Error('Cannot represent value as ID: ' . Utils::printSafe($value));
    }

    /**
     * @param Node         $valueNode
     * @param mixed[]|null $variables
     *
     * @return string|null
     *
     * @throws Exception
     */
    public function parseLiteral($valueNode, ?array $variables = null)
    {
        if ($valueNode instanceof StringValueNode || $valueNode instanceof IntValueNode) {
            return $valueNode->value;
        }

        // Intentionally without message, as all information already in wrapped Exception
        throw new Exception();
    }
}