<?php

namespace App\Support;

use App\Mail\OperationalAlertMail;
use Illuminate\Support\Facades\Http;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Facades\Mail;
use Illuminate\Support\Str;
use Throwable;

/**
 * Zentrale Betriebs-Alerts (R5.3): meldet fehlgeschlagene Scheduler-Tasks und
 * Queue-Jobs. Der Log-Eintrag (`critical`) ist die verlässliche Ebene und läuft
 * immer; Mail und ntfy-Push (Monitoring-Plan M3) sind Best-Effort, unabhängig
 * voneinander, und dürfen den auslösenden Prozess nie mit in den Abgrund
 * reißen (Mailserver down, ntfy nicht erreichbar o. ä.).
 */
class OperationalAlert
{
    /**
     * @param  array<string, mixed>  $context
     */
    public static function send(string $summary, array $context = []): void
    {
        Log::channel('monitoring')->critical('[monitoring] '.$summary, $context);

        if (! config('monitoring.alerts.enabled')) {
            return;
        }

        self::mail($summary, $context);
        self::push($summary, $context);
    }

    /**
     * @param  array<string, mixed>  $context
     */
    private static function mail(string $summary, array $context): void
    {
        $recipient = config('monitoring.alerts.mail_to');

        if (empty($recipient)) {
            return;
        }

        try {
            Mail::to($recipient)->send(new OperationalAlertMail($summary, $context));
        } catch (Throwable $e) {
            Log::channel('monitoring')->error('[monitoring] Alert-Mail konnte nicht versendet werden.', [
                'summary' => $summary,
                'error' => $e->getMessage(),
            ]);
        }
    }

    /**
     * JSON-Publish an die ntfy-Basis-URL (UTF-8-sicher, anders als Header).
     *
     * @param  array<string, mixed>  $context
     */
    private static function push(string $summary, array $context): void
    {
        $url = (string) config('monitoring.alerts.ntfy.url');
        $topic = (string) config('monitoring.alerts.ntfy.topic');

        if ($url === '' || $topic === '') {
            return;
        }

        $details = collect($context)
            ->map(fn (mixed $value, string $key): string => $key.': '.(is_scalar($value) || $value === null ? (string) $value : json_encode($value)))
            ->implode("\n");

        try {
            Http::timeout(5)
                ->connectTimeout(3)
                ->when(filled(config('monitoring.alerts.ntfy.token')), fn ($request) => $request->withToken((string) config('monitoring.alerts.ntfy.token')))
                ->post(rtrim($url, '/'), [
                    'topic' => $topic,
                    'title' => config('app.name').' ('.app()->environment().'): Betriebs-Alert',
                    'message' => Str::limit(trim($summary."\n\n".$details), 3500),
                    'priority' => (int) config('monitoring.alerts.ntfy.priority'),
                    'tags' => ['rotating_light'],
                ])
                ->throw();
        } catch (Throwable $e) {
            Log::channel('monitoring')->error('[monitoring] ntfy-Push konnte nicht versendet werden.', [
                'summary' => $summary,
                'error' => $e->getMessage(),
            ]);
        }
    }
}