<?php

namespace App\Services\Ssl;

use App\Models\CustomerHostingOrder;
use App\Models\Domain;
use App\Models\HostedSite;
use App\Models\HostingNode;
use App\Models\ServerSite;
use App\Models\ServerTask;
use App\Notifications\SslExpiringNotification;
use App\Services\Hosting\Providers\SharedNodeProvider;
use Carbon\CarbonInterface;
use Illuminate\Support\Collection;
use Illuminate\Support\Facades\Log;

class SslRenewalService
{
    public function __construct(
        private readonly SharedNodeProvider $nodeProvider,
        private readonly SslProvisioner $sslProvisioner,
    ) {
    }

    /**
     * @return array{nodes: int, central: bool, server_orders: int, sites_synced: int, domains_synced: int, fallbacks: int}
     */
    public function renewAll(bool $force = false, bool $dryRun = false): array
    {
        $stats = [
            'nodes' => 0,
            'central' => false,
            'server_orders' => 0,
            'sites_synced' => 0,
            'domains_synced' => 0,
            'fallbacks' => 0,
        ];

        if ($dryRun) {
            $stats['nodes'] = $this->sharedNodesWithSsl()->count();
            $stats['central'] = $this->sslProvisioner->isConfigured() && $this->centralDomainsNeedingRenewal()->isNotEmpty();
            $stats['server_orders'] = $this->managedServerOrdersNeedingRenewal()->count();

            return $stats;
        }

        foreach ($this->sharedNodesWithSsl() as $node) {
            try {
                $this->nodeProvider->renewCertificatesOnNode($node, $force);
                $stats['nodes']++;
            } catch (\Throwable $exception) {
                Log::error('SslRenewalService: node renew failed', [
                    'node_id' => $node->id,
                    'error' => $exception->getMessage(),
                ]);
            }

            $stats['sites_synced'] += $this->syncHostedSiteExpiriesForNode($node);
        }

        if ($this->sslProvisioner->isConfigured()) {
            $centralDomains = $this->centralDomainsNeedingRenewal();
            if ($centralDomains->isNotEmpty()) {
                $this->sslProvisioner->renewCertificates($force);
                $this->sslProvisioner->reloadNginx();
                $stats['central'] = true;
                $stats['domains_synced'] += $this->syncCentralDomainExpiries($centralDomains);
            }
        }

        $stats['server_orders'] = $this->queueManagedServerRenewals();
        $stats['fallbacks'] = $this->reissueExpiringHostedSites();

        $this->notifyExpiringDomains();

        return $stats;
    }

    /**
     * @return Collection<int, HostingNode>
     */
    private function sharedNodesWithSsl(): Collection
    {
        $nodeIds = HostedSite::query()
            ->where('ssl_enabled', true)
            ->where('status', 'active')
            ->whereHas('account', function ($query): void {
                $query->where('status', 'active')
                    ->whereNotNull('hosting_node_id');
            })
            ->with('account:id,hosting_node_id')
            ->get()
            ->pluck('account.hosting_node_id')
            ->filter()
            ->unique()
            ->values();

        if ($nodeIds->isEmpty()) {
            return collect();
        }

        return HostingNode::query()
            ->whereIn('id', $nodeIds)
            ->where('type', HostingNode::TYPE_SHARED)
            ->where('status', 'active')
            ->get();
    }

    public function syncHostedSiteExpiriesForNode(HostingNode $node): int
    {
        $sites = HostedSite::query()
            ->where('ssl_enabled', true)
            ->where('status', 'active')
            ->whereHas('account', function ($query) use ($node): void {
                $query->where('status', 'active')
                    ->where('hosting_node_id', $node->id);
            })
            ->get();

        $synced = 0;

        foreach ($sites as $site) {
            $expiresAt = $this->readHostedSiteExpiry($node, $site);
            if ($expiresAt === null) {
                continue;
            }

            $site->update(['ssl_expires_at' => $expiresAt]);
            $synced++;

            if ($site->domain_id) {
                Domain::query()
                    ->whereKey($site->domain_id)
                    ->update([
                        'ssl_status' => 'active',
                        'ssl_expires_at' => $expiresAt,
                    ]);
            }
        }

        return $synced;
    }

    private function readHostedSiteExpiry(HostingNode $node, HostedSite $site): ?CarbonInterface
    {
        try {
            return $this->nodeProvider->readCertificateExpiryOnNode($node, $site->domain);
        } catch (\Throwable $exception) {
            Log::warning('SslRenewalService: could not read certificate expiry', [
                'site_id' => $site->id,
                'domain' => $site->domain,
                'error' => $exception->getMessage(),
            ]);

            return null;
        }
    }

    /**
     * Domains with active SSL on the central web server (not served from a shared node cert).
     *
     * @return Collection<int, Domain>
     */
    private function centralDomainsNeedingRenewal(): Collection
    {
        return Domain::query()
            ->where('ssl_status', 'active')
            ->whereDoesntHave('hostedSites', function ($query): void {
                $query->where('ssl_enabled', true)
                    ->where('status', 'active')
                    ->whereHas('account', fn ($account) => $account->where('status', 'active'));
            })
            ->get();
    }

    /**
     * @param  Collection<int, Domain>  $domains
     */
    private function syncCentralDomainExpiries(Collection $domains): int
    {
        $synced = 0;

        foreach ($domains as $domain) {
            $expiresAt = $this->sslProvisioner->readCertificateExpiry($domain->host);
            if ($expiresAt === null) {
                continue;
            }

            $domain->update(['ssl_expires_at' => $expiresAt]);
            $synced++;
        }

        return $synced;
    }

    private function queueManagedServerRenewals(): int
    {
        $queued = 0;

        foreach ($this->managedServerOrdersNeedingRenewal() as $order) {
            $existing = ServerTask::query()
                ->where('customer_hosting_order_id', $order->id)
                ->where('type', ServerTask::TYPE_SSL_RENEW)
                ->whereIn('status', [
                    ServerTask::STATUS_QUEUED,
                    ServerTask::STATUS_DISPATCHED,
                    ServerTask::STATUS_RUNNING,
                ])
                ->exists();

            if ($existing) {
                continue;
            }

            ServerTask::create([
                'customer_hosting_order_id' => $order->id,
                'server_agent_id' => $order->serverAgent?->id,
                'type' => ServerTask::TYPE_SSL_RENEW,
                'status' => ServerTask::STATUS_QUEUED,
                'payload' => [],
                'progress' => 0,
                'max_attempts' => 3,
                'retry_backoff_seconds' => 60,
                'stale_after_seconds' => 300,
                'queued_at' => now(),
                'available_at' => now(),
            ]);

            $queued++;
        }

        return $queued;
    }

    /**
     * @return Collection<int, CustomerHostingOrder>
     */
    private function managedServerOrdersNeedingRenewal(): Collection
    {
        $orderIds = ServerSite::query()
            ->whereIn('ssl_status', ['issued', 'active'])
            ->pluck('customer_hosting_order_id')
            ->unique()
            ->filter();

        if ($orderIds->isEmpty()) {
            return collect();
        }

        return CustomerHostingOrder::query()
            ->whereIn('id', $orderIds)
            ->whereHas('serverAgent')
            ->with('serverAgent')
            ->get();
    }

    private function reissueExpiringHostedSites(): int
    {
        $thresholdDays = (int) config('ssl.fallback_reissue_before_days', 10);
        $threshold = now()->addDays($thresholdDays);

        $sites = HostedSite::query()
            ->where('ssl_enabled', true)
            ->where('status', 'active')
            ->where(function ($query) use ($threshold): void {
                $query->whereNull('ssl_expires_at')
                    ->orWhere('ssl_expires_at', '<=', $threshold);
            })
            ->whereHas('account', fn ($query) => $query->where('status', 'active'))
            ->with(['account.node', 'account.user'])
            ->get();

        $reissued = 0;

        foreach ($sites as $site) {
            if (! $site->account?->node) {
                continue;
            }

            try {
                $this->nodeProvider->requestLetsEncryptCertificate($site);
                $expiresAt = $this->readHostedSiteExpiry($site->account->node, $site);
                $site->update(array_filter([
                    'ssl_status' => 'issued',
                    'ssl_error' => null,
                    'ssl_expires_at' => $expiresAt,
                    'ssl_provisioned_at' => now(),
                ]));
                $reissued++;
            } catch (\Throwable $exception) {
                Log::warning('SslRenewalService: fallback re-issue failed', [
                    'site_id' => $site->id,
                    'domain' => $site->domain,
                    'error' => $exception->getMessage(),
                ]);
            }
        }

        return $reissued;
    }

    private function notifyExpiringDomains(): void
    {
        Domain::query()
            ->where('ssl_status', 'active')
            ->whereNotNull('ssl_expires_at')
            ->where('ssl_expires_at', '>', now())
            ->with('website.user')
            ->each(function (Domain $domain): void {
                $user = $domain->website?->user;
                if ($user === null) {
                    return;
                }

                $daysUntilExpiry = (int) now()->startOfDay()->diffInDays(
                    $domain->ssl_expires_at->copy()->startOfDay(),
                    false
                );

                $milestones = array_map('intval', (array) config('notifications.ssl_expiry_milestones', [14, 7, 3, 1]));

                if (! in_array($daysUntilExpiry, $milestones, true)) {
                    return;
                }

                $user->notify(new SslExpiringNotification($domain, $daysUntilExpiry));
            });
    }
}