<?php

namespace App\Services\CustomDomain;

use App\Models\LinkCustomDomain;
use App\Models\User;
use Illuminate\Support\Carbon;
use Illuminate\Support\Facades\DB;

class LinkCustomDomainService
{
    public function __construct(
        private readonly DnsResolver $dns,
        private readonly DomainsSslClient $ssl,
    ) {}

    public function enabled(): bool
    {
        return (bool) config('customdomain.enabled', true) && $this->ssl->configured();
    }

    public function attach(User $user, string $host, bool $includeWww = true, bool $makeDefault = false): LinkCustomDomain
    {
        return DB::transaction(function () use ($user, $host, $includeWww, $makeDefault) {
            if ($makeDefault) {
                LinkCustomDomain::where('user_id', $user->id)->update(['is_default' => false]);
            }

            return LinkCustomDomain::create([
                'user_id' => $user->id,
                'host' => $host,
                'include_www' => $includeWww,
                'is_default' => $makeDefault || ! LinkCustomDomain::where('user_id', $user->id)->exists(),
                'status' => LinkCustomDomain::STATUS_PENDING,
                'ssl_status' => LinkCustomDomain::STATUS_PENDING,
            ]);
        });
    }

    /** @return array{0:bool,1:string} */
    public function verifyAndProvision(LinkCustomDomain $domain): array
    {
        $serverIp = (string) config('customdomain.server_ip');
        $ips = $this->dns->aRecords($domain->host);

        if (! in_array($serverIp, $ips, true)) {
            $domain->forceFill([
                'last_error' => 'DNS not pointing to '.$serverIp.' yet (found: '.(implode(', ', $ips) ?: 'none').').',
            ])->save();

            return [false, 'DNS not verified yet. Add an A record for '.$domain->host.' pointing to '.$serverIp.', then try again.'];
        }

        $domain->forceFill(['dns_verified_at' => Carbon::now(), 'last_error' => null])->save();

        $requested = $this->ssl->requestCertificate(
            $domain->host,
            $domain->include_www,
            route('api.ssl-callback'),
        );

        if (! $requested) {
            $domain->forceFill(['last_error' => 'Could not reach the SSL service. Please try again shortly.'])->save();

            return [false, 'Domain verified, but issuing the certificate failed. Please retry in a moment.'];
        }

        return [true, 'Domain verified. Issuing your SSL certificate — this usually takes under a minute.'];
    }

    public function applyCallback(string $host, string $status, ?string $expiresAt, ?string $error): void
    {
        $domain = LinkCustomDomain::where('host', strtolower(trim($host)))->first();
        if (! $domain) {
            return;
        }

        if ($status === 'active') {
            $domain->forceFill([
                'ssl_status' => LinkCustomDomain::STATUS_ACTIVE,
                'status' => LinkCustomDomain::STATUS_ACTIVE,
                'ssl_issued_at' => Carbon::now(),
                'ssl_expires_at' => $expiresAt ? Carbon::parse($expiresAt) : null,
                'last_error' => null,
            ])->save();
        } else {
            $domain->forceFill([
                'ssl_status' => LinkCustomDomain::STATUS_FAILED,
                'status' => LinkCustomDomain::STATUS_FAILED,
                'last_error' => $error ?: 'Certificate issuance failed.',
            ])->save();
        }
    }

    public function setDefault(LinkCustomDomain $domain): void
    {
        DB::transaction(function () use ($domain) {
            LinkCustomDomain::where('user_id', $domain->user_id)->update(['is_default' => false]);
            $domain->forceFill(['is_default' => true])->save();
        });
    }

    public function isAppHost(string $host): bool
    {
        $host = preg_replace('/^www\./', '', strtolower(trim($host)));
        $public = (string) config('customdomain.public_host', config('link.public_domain', 'ladl.link'));
        $known = array_filter([
            (string) config('customdomain.app_host'),
            $public,
            'www.'.$public,
        ]);

        return in_array($host, $known, true);
    }
}