<?php

declare(strict_types=1);

namespace UploadLogger\Core;

/**
 * Structured JSON logger with request context.
 */
final class Logger
{
    private string $logFile;

    /** @var array<string, mixed> */
    private array $context;

    /**
     * @param array<string, mixed> $context
     */
    public function __construct(string $logFile, array $context = [], ?Config $config = null)
    {
        $this->logFile = $logFile;
        $this->context = $context;
        // Keep optional config parameter for backward compatibility (unused here)
        unset($config);
    }

    /**
     * @param array<string, mixed> $context
     */
    public function setContext(array $context): void
    {
        $this->context = $context;
    }

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

        $payload = $this->normalizeValue($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 normalizeValue(mixed $value): mixed
    {
        if (is_array($value)) {
            $out = [];
            foreach ($value as $k => $v) {
                $out[$k] = $this->normalizeValue($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);
    }
}