<?php

namespace App\Services\Domain;

use App\Models\Domain;
use App\Models\DomainDkimKey;
use Illuminate\Support\Facades\File;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;

class DomainDkimService
{
    public function ensureActive(Domain $domain): DomainDkimKey
    {
        $existing = DomainDkimKey::query()
            ->where('domain_id', $domain->id)
            ->where('status', 'active')
            ->latest('id')
            ->first();

        if ($existing) {
            return $existing;
        }

        $selectorPrefix = (string) config('mailinfra.dkim_selector_prefix', 'ladill');
        $selector = Str::lower(trim($selectorPrefix)) ?: 'ladill';
        $selector .= '1';

        $publicKey = '';
        $privateKey = null;

        if (function_exists('openssl_pkey_new')) {
            $resource = openssl_pkey_new([
                'private_key_bits' => 2048,
                'private_key_type' => OPENSSL_KEYTYPE_RSA,
            ]);

            if ($resource !== false) {
                openssl_pkey_export($resource, $privateOut);
                $details = openssl_pkey_get_details($resource);
                $publicPem = (string) ($details['key'] ?? '');
                $publicKey = preg_replace('/-----BEGIN PUBLIC KEY-----|-----END PUBLIC KEY-----|\s+/', '', $publicPem) ?: '';
                $privateKey = $privateOut ?: null;
            }
        }

        if ($publicKey === '') {
            $publicKey = Str::upper(Str::random(360));
        }

        $privatePath = null;
        if (is_string($privateKey) && trim($privateKey) !== '') {
            $safeHost = Str::slug($domain->host, '_');
            $directory = storage_path('app/mail/dkim');
            File::ensureDirectoryExists($directory);
            $privatePath = $directory.'/'.$safeHost.'_'.$selector.'.key';
            File::put($privatePath, $privateKey);
        }

        $key = DomainDkimKey::query()->create([
            'domain_id' => $domain->id,
            'selector' => $selector,
            'public_key_txt' => $publicKey,
            'private_key_path' => $privatePath,
            'status' => 'active',
            'generated_at' => now(),
        ]);

        Log::info('Generated DKIM key for domain', ['domain_id' => $domain->id, 'selector' => $selector]);

        return $key;
    }

    public function activeKey(Domain $domain): ?DomainDkimKey
    {
        return DomainDkimKey::query()
            ->where('domain_id', $domain->id)
            ->where('status', 'active')
            ->latest('id')
            ->first();
    }
}