<?php

declare(strict_types=1);

namespace Kreait\Firebase\Messaging;

use Kreait\Firebase\Exception\InvalidArgumentException;

final class MessageData implements \JsonSerializable
{
    /** @var array */
    private $data = [];

    private function __construct()
    {
    }

    public static function fromArray(array $data): self
    {
        $messageData = new self();

        foreach ($data as $key => $value) {
            if (!self::isStringable($key) || !self::isStringable($value)) {
                throw new InvalidArgumentException('Message data must be a one-dimensional array of string(able) keys and values.');
            }

            $messageData->data[(string) $key] = (string) $value;
        }

        return $messageData;
    }

    public function jsonSerialize()
    {
        return $this->data;
    }

    private static function isStringable($value): bool
    {
        return \is_null($value) || \is_scalar($value) || (\is_object($value) && \method_exists($value, '__toString'));
    }
}