<?php
declare(strict_types=1);
namespace UploadLogger\Core\Services;

final class LogService
{
    private string $logFile;
    /** @var array<string,mixed> */
    private array $ctx;

    /**
     * @param string $logFile
     * @param array<string,mixed> $ctx
     */
    public function __construct(string $logFile, array $ctx = [])
    {
        $this->logFile = $logFile;
        $this->ctx = $ctx;
    }

    /**
     * @param string $event
     * @param array<string,mixed> $data
     */
    public function logEvent(string $event, array $data = []): void
    {
        $payload = array_merge(['ts' => gmdate('c'), 'event' => $event], $this->ctx, $data);

        $payload = $this->normalize($payload);

        $json = json_encode($payload, JSON_UNESCAPED_SLASHES);
        if ($json === false) {
            $json = json_encode([
                'ts' => gmdate('c'),
                'event' => 'log_error',
                'error' => json_last_error_msg(),
            ], JSON_UNESCAPED_SLASHES);
        }

        @file_put_contents($this->logFile, $json . "\n", FILE_APPEND | LOCK_EX);
    }

    private function normalize(mixed $value): mixed
    {
        if (is_array($value)) {
            $out = [];
            foreach ($value as $k => $v) {
                $out[$k] = $this->normalize($v);
            }
            return $out;
        }

        if (is_bool($value) || is_int($value) || is_float($value) || $value === null) {
            return $value;
        }

        $str = (string)$value;
        return preg_replace('/[\x00-\x1F\x7F]/', '_', $str);
    }
}