<?php
namespace App\Console\Commands;

use App\Models\Device;
use Illuminate\Console\Command;
use Illuminate\Support\Facades\Cache;
use Illuminate\Support\Facades\Mail;

class HealthCheck extends Command
{
    protected $signature = 'heizung:healthcheck
        {--stale=5 : Minutes without data = alarm}
        {--notify= : Email address for alerts}
        {--sms= : Phone number for mail2sms}';
    protected $description = 'Check device liveness and alert on state changes';

    public function handle(): int
    {
        $stale = (int) $this->option('stale');
        $email = $this->option('notify') ?: env('HEALTHCHECK_EMAIL');
        $sms = $this->option('sms') ?: env('HEALTHCHECK_SMS');
        $th = now()->subMinutes($stale);
        $problems = 0;
        foreach (Device::all() as $d) {
            $down = !$d->last_seen_at || $d->last_seen_at->lt($th);
            $prev = Cache::get("hc:d:{$d->id}", 'ok');
            $new = $down ? 'down' : 'ok';
            $this->line("$d->name: $new");
            if ($new !== $prev) {
                $this->notify($d, $new, $email, $sms);
                Cache::put("hc:d:{$d->id}", $new, now()->addDays(30));
            }
            $problems += $down ? 1 : 0;
        }
        return $problems > 0 ? 1 : 0;
    }

    private function notify(Device $d, string $state, ?string $email, ?string $sms): void
    {
        if ($state === 'down') {
            $subj = "[ALARM] Heizung {$d->name} offline";
            $body = "'{$d->name}' seit ".($d->last_seen_at?->diffForHumans() ?? 'immer').
                " keine Daten.\nLast seen: ".($d->last_seen_at?->toDateTimeString() ?? 'nie');
        } else {
            $subj = "[OK] Heizung {$d->name} wieder online";
            $body = "'{$d->name}' liefert wieder Daten.\nLast seen: ".$d->last_seen_at?->toDateTimeString();
        }
        if ($email) $this->sendMail($email, $subj, $body);
        if ($sms) $this->sendSms($sms, $subj, $body);
        $this->warn("notify: $subj");
    }

    private function sendMail(string $to, string $subj, string $body): void
    {
        try {
            Mail::raw($body, function ($m) use ($to, $subj) {
                $m->to($to)->subject($subj);
            });
        } catch (\Throwable $e) {
            $this->error("Mail failed: ".$e->getMessage());
        }
    }

    private function sendSms(string $number, string $subj, string $body): void
    {
        // mail2sms Gateway: subject=Nummer, body=Text
        try {
            Mail::raw(substr($subj.' '.$body, 0, 140), function ($m) use ($number) {
                $m->to('mail2sms@dimedtec.net')->subject($number);
            });
        } catch (\Throwable $e) {
            $this->error("SMS failed: ".$e->getMessage());
        }
    }
}