<?php declare(strict_types=1);

/*
 * This file is part of the Monolog package.
 *
 * (c) Jordi Boggiano <j.boggiano@seld.be>
 *
 * For the full copyright and license information, please view the LICENSE
 * file that was distributed with this source code.
 */

namespace Monolog\Formatter;

use DateTimeInterface;
use Monolog\LogRecord;

/**
 * Encodes message information into JSON in a format compatible with Cloud logging.
 *
 * @see https://cloud.google.com/logging/docs/structured-logging
 * @see https://cloud.google.com/logging/docs/reference/v2/rest/v2/LogEntry
 *
 * @author Luís Cobucci <lcobucci@gmail.com>
 */
final class GoogleCloudLoggingFormatter extends JsonFormatter
{
    /** {@inheritdoc} **/
    public function format(array $record): string
    {
        // Re-key level for GCP logging
        $record['severity'] = $record['level_name'];
        $record['time'] = $record['datetime']->format(DateTimeInterface::RFC3339_EXTENDED);

        // Remove keys that are not used by GCP
        unset($record['level'], $record['level_name'], $record['datetime']);

        return parent::format($record);
    }
}