<?php

namespace App\Integrations\Whmcs\Support;

use Illuminate\Support\Facades\DB;

/**
 * Ensures a WHMCS customer domain also exists in the DNS manager (dns_manager_domain) and is
 * linked to the customer (dns_domain_user) — that pivot is what the customer's "Domains" panel
 * in the admin actually reads (fetchCustomerDnsDomains), not module_domain.
 */
class DnsDomainLinker
{
    private static ?int $canonicalServerId = null;

    public function link(string $domainName, int $customerId, ?int $registrarId = null): void
    {
        $domainId = DB::table('dns_manager_domain')->whereRaw('LOWER(domain_name) = ?', [mb_strtolower($domainName)])->value('id');

        if (! $domainId) {
            $serverId = $this->canonicalServerId();
            if (! $serverId) {
                return;
            }

            $domainId = DB::table('dns_manager_domain')->insertGetId([
                'domain_name' => $domainName,
                'dns_manager_server_id' => $serverId,
                // not a real provisioned DNS zone, just a billing placeholder created from WHMCS
                'is_created' => 0,
                'registrar_id' => $registrarId,
                'created_at' => now(),
                'updated_at' => now(),
            ]);
        } elseif ($registrarId !== null) {
            // don't clobber an existing registrar with an unresolved (null) one from a later re-sync
            DB::table('dns_manager_domain')->where('id', $domainId)->update(['registrar_id' => $registrarId]);
        }

        DB::table('dns_domain_user')->updateOrInsert(
            ['domain_id' => $domainId, 'user_id' => $customerId],
            ['created_at' => now(), 'updated_at' => now()]
        );
    }

    private function canonicalServerId(): ?int
    {
        return self::$canonicalServerId ??= DB::table('dns_manager_servers')
            ->orderByRaw('CASE WHEN id = 1 THEN 0 ELSE 1 END')
            ->orderBy('id')
            ->value('id');
    }
}