<?php

namespace App\Services\Infrastructure;

use App\Jobs\ProvisionContaboInfrastructureJob;
use App\Models\ContaboInfrastructureProvision;
use App\Models\EmailServer;
use App\Models\HostingNode;
use App\Models\User;
use App\Services\Hosting\Providers\ContaboProvider;
use App\Services\Mail\EmailServerPoolService;
use App\Services\Mail\MailServerNfsService;
use Illuminate\Support\Str;

class ContaboInfrastructureProvisioner
{
    public function __construct(
        private ContaboProvider $contabo,
        private ContaboInfrastructureSshKeyService $sshKeys,
        private ContaboInfrastructureCloudInitBuilder $cloudInit,
        private EmailServerPoolService $emailPool,
        private MailServerNfsService $mailNfs,
    ) {}

    public function isEnabled(): bool
    {
        return (bool) config('infrastructure.contabo.enabled', true)
            && config('hosting.contabo.client_id')
            && config('hosting.contabo.client_secret');
    }

    /**
     * @param  array<string, mixed>  $input
     */
    public function startHostingNode(array $input, ?User $actor = null): ContaboInfrastructureProvision
    {
        $this->assertEnabled();

        $keys = $this->sshKeys->generate();
        $placeholderIp = (string) config('infrastructure.contabo.placeholder_ip', '169.254.254.254');

        $node = HostingNode::create([
            'name' => (string) $input['name'],
            'hostname' => (string) $input['hostname'],
            'ip_address' => $placeholderIp,
            'type' => (string) ($input['type'] ?? HostingNode::TYPE_SHARED),
            'role' => (string) ($input['role'] ?? HostingNode::ROLE_PRIMARY),
            'primary_hosting_node_id' => $input['primary_hosting_node_id'] ?? null,
            'segment' => (string) ($input['segment'] ?? HostingNode::SEGMENT_GENERAL),
            'provider' => HostingNode::PROVIDER_CONTABO,
            'region' => (string) ($input['region'] ?? config('infrastructure.contabo.default_region', 'EU')),
            'cpu_cores' => $input['cpu_cores'] ?? null,
            'ram_mb' => $input['ram_mb'] ?? null,
            'disk_gb' => $input['disk_gb'] ?? null,
            'bandwidth_tb' => $input['bandwidth_tb'] ?? null,
            'max_accounts' => (int) ($input['max_accounts'] ?? 100),
            'oversell_ratio' => (float) ($input['oversell_ratio'] ?? 3),
            'ssh_port' => 22,
            'ssh_private_key' => $keys['private_key'],
            'status' => HostingNode::STATUS_PROVISIONING,
        ]);

        $provision = $this->createProvision(
            purpose: ContaboInfrastructureProvision::PURPOSE_HOSTING_NODE,
            name: (string) $input['name'],
            productId: (string) ($input['contabo_product_id'] ?? config('infrastructure.contabo.hosting_product_id', 'V97')),
            region: (string) ($input['region'] ?? config('infrastructure.contabo.default_region', 'EU')),
            imageId: (string) ($input['image_id'] ?? config('infrastructure.contabo.default_image_id')),
            payload: $input,
            keys: $keys,
            hostingNodeId: $node->id,
            actor: $actor,
        );

        ProvisionContaboInfrastructureJob::dispatch($provision);

        return $provision;
    }

    /**
     * @param  array<string, mixed>  $input
     */
    public function startEmailServer(array $input, ?User $actor = null): ContaboInfrastructureProvision
    {
        $this->assertEnabled();

        $isExtension = ($input['role'] ?? EmailServer::ROLE_PRIMARY) === EmailServer::ROLE_EXTENSION;
        $keys = $this->sshKeys->generate();
        $mailHost = (string) ($input['mail_host'] ?? config('mailinfra.mail_host', 'mail.ladill.com'));
        $placeholderIp = (string) config('infrastructure.contabo.placeholder_ip', '169.254.254.254');
        $mailDbPassword = $isExtension ? null : Str::password(32);

        $primary = null;
        if ($isExtension) {
            $primary = EmailServer::findOrFail($input['primary_email_server_id']);
        }

        $server = EmailServer::create([
            'name' => (string) $input['name'],
            'hostname' => (string) ($input['hostname'] ?? $mailHost),
            'ip_address' => $placeholderIp,
            'mail_host' => $mailHost,
            'role' => $isExtension ? EmailServer::ROLE_EXTENSION : EmailServer::ROLE_PRIMARY,
            'primary_email_server_id' => $primary?->id,
            'provider' => EmailServer::PROVIDER_CONTABO,
            'region' => (string) ($input['region'] ?? config('infrastructure.contabo.default_region', 'EU')),
            'cpu_cores' => $input['cpu_cores'] ?? null,
            'ram_mb' => $input['ram_mb'] ?? null,
            'disk_gb' => $input['disk_gb'] ?? null,
            'max_domains' => $input['max_domains'] ?? 5000,
            'max_mailboxes' => $input['max_mailboxes'] ?? 50000,
            'db_host' => $isExtension ? $primary?->db_host : config('infrastructure.mail_stack.db_host'),
            'db_port' => $primary?->db_port ?? 3306,
            'db_database' => config('infrastructure.mail_stack.db_database', 'mail'),
            'db_username' => $isExtension ? $primary?->db_username : config('infrastructure.mail_stack.db_username', 'mailuser'),
            'db_password' => $isExtension ? $primary?->db_password : $mailDbPassword,
            'ssh_host' => null,
            'ssh_user' => 'root',
            'ssh_port' => 22,
            'ssh_private_key' => $keys['private_key'],
            'status' => EmailServer::STATUS_PROVISIONING,
            'is_default' => ! $isExtension && (bool) ($input['is_default'] ?? false),
        ]);

        if ($isExtension && $primary) {
            $this->emailPool->syncExtensionFromPrimary($server, $primary);
        }

        $purpose = $isExtension
            ? ContaboInfrastructureProvision::PURPOSE_EMAIL_EXTENSION
            : ContaboInfrastructureProvision::PURPOSE_EMAIL_PRIMARY;

        $productId = $isExtension
            ? (string) ($input['contabo_product_id'] ?? config('infrastructure.contabo.mail_extension_product_id', 'V94'))
            : (string) ($input['contabo_product_id'] ?? config('infrastructure.contabo.mail_primary_product_id', 'V97'));

        $provision = $this->createProvision(
            purpose: $purpose,
            name: (string) $input['name'],
            productId: $productId,
            region: (string) ($input['region'] ?? config('infrastructure.contabo.default_region', 'EU')),
            imageId: (string) ($input['image_id'] ?? config('infrastructure.contabo.default_image_id')),
            payload: array_merge($input, [
                'mail_host' => $mailHost,
                'primary_ip' => $primary?->ip_address,
                'primary_email_server_id' => $primary?->id,
            ]),
            keys: $keys,
            emailServerId: $server->id,
            mailDbPassword: $mailDbPassword,
            actor: $actor,
        );

        ProvisionContaboInfrastructureJob::dispatch($provision);

        return $provision;
    }

    public function createContaboInstance(ContaboInfrastructureProvision $provision): void
    {
        $provision->update(['status' => ContaboInfrastructureProvision::STATUS_CREATING]);
        $provision->addLog('Creating Contabo compute instance…');

        $userData = $this->cloudInit->build($provision);

        $result = $this->contabo->createInstance([
            'product_id' => $provision->contabo_product_id,
            'region' => $provision->region,
            'image_id' => $provision->image_id,
            'display_name' => 'ladill-'.$provision->purpose.'-'.$provision->id,
            'user_data' => $userData,
            'default_user' => 'root',
        ]);

        $provision->update([
            'contabo_instance_id' => $result['instance_id'],
            'status' => ContaboInfrastructureProvision::STATUS_WAITING_IP,
            'instance_created_at' => now(),
        ]);

        if ($provision->hosting_node_id) {
            HostingNode::whereKey($provision->hosting_node_id)->update([
                'provider_instance_id' => $result['instance_id'],
                'cpu_cores' => $result['cpu_cores'] ?? null,
                'ram_mb' => $result['ram_mb'] ?? null,
                'disk_gb' => isset($result['disk_mb']) ? (int) ceil($result['disk_mb'] / 1024) : null,
            ]);
        }

        if ($provision->email_server_id) {
            EmailServer::whereKey($provision->email_server_id)->update([
                'provider_instance_id' => $result['instance_id'],
                'cpu_cores' => $result['cpu_cores'] ?? null,
                'ram_mb' => $result['ram_mb'] ?? null,
                'disk_gb' => isset($result['disk_mb']) ? (int) ceil($result['disk_mb'] / 1024) : null,
            ]);
        }

        $provision->addLog('Instance '.$result['instance_id'].' created; waiting for IP address.');
    }

    public function pollInstanceIp(ContaboInfrastructureProvision $provision): bool
    {
        if (! $provision->contabo_instance_id) {
            return false;
        }

        $instance = $this->contabo->getInstance($provision->contabo_instance_id);
        $ip = $instance['ip_address'] ?? null;

        if (! is_string($ip) || $ip === '' || $ip === '0.0.0.0') {
            return false;
        }

        $provision->update([
            'status' => ContaboInfrastructureProvision::STATUS_BOOTSTRAPPING,
            'ip_assigned_at' => now(),
        ]);
        $provision->addLog("Instance IP assigned: {$ip}");

        if ($provision->hosting_node_id) {
            HostingNode::whereKey($provision->hosting_node_id)->update([
                'ip_address' => $ip,
                'ipv6_address' => $instance['ipv6_address'] ?? null,
            ]);
        }

        if ($provision->email_server_id) {
            EmailServer::whereKey($provision->email_server_id)->update([
                'ip_address' => $ip,
                'ipv6_address' => $instance['ipv6_address'] ?? null,
                'ssh_host' => $ip,
            ]);
            // Note: db_host is intentionally NOT set to the server's own IP.
            // The mail DB is centralized; primaries keep the central db_host.
        }

        return true;
    }

    /**
     * @param  array<string, mixed>  $callback
     */
    public function completeFromCallback(ContaboInfrastructureProvision $provision, array $callback): void
    {
        if ($provision->status === ContaboInfrastructureProvision::STATUS_COMPLETED) {
            return;
        }

        $provision->addLog('Bootstrap completion callback received.');

        if ($provision->email_server_id) {
            $server = EmailServer::find($provision->email_server_id);
            if ($server?->isPrimary()) {
                EmailServer::whereKey($server->id)->update([
                    // Mail DB is centralized — point at the central host, not the server IP.
                    'db_host' => config('infrastructure.mail_stack.db_host'),
                    'ssh_host' => $server->ip_address,
                ]);
                $this->emailPool->syncExtensionCredentials($server->fresh());
            }

            if ($server?->isExtension() && $server->primary) {
                $this->mailNfs->refreshPrimaryExports($server->primary);
            }
        }

        $this->activateResources($provision);

        $provision->update([
            'status' => ContaboInfrastructureProvision::STATUS_COMPLETED,
            'completed_at' => now(),
        ]);
        $provision->addLog('Provisioning completed successfully.');
    }

    public function activateResources(ContaboInfrastructureProvision $provision): void
    {
        if ($provision->hosting_node_id) {
            HostingNode::whereKey($provision->hosting_node_id)->update([
                'status' => HostingNode::STATUS_ACTIVE,
            ]);
        }

        if ($provision->email_server_id) {
            EmailServer::whereKey($provision->email_server_id)->update([
                'status' => EmailServer::STATUS_ACTIVE,
            ]);
        }
    }

    public function retry(ContaboInfrastructureProvision $provision): void
    {
        if ($provision->status !== ContaboInfrastructureProvision::STATUS_FAILED) {
            return;
        }

        $provision->update([
            'status' => ContaboInfrastructureProvision::STATUS_PENDING,
            'error_message' => null,
            'failed_at' => null,
        ]);
        $provision->addLog('Retry requested.');

        ProvisionContaboInfrastructureJob::dispatch($provision);
    }

    /**
     * @param  array<string, mixed>  $payload
     * @param  array{public_key: string, private_key: string}  $keys
     */
    private function createProvision(
        string $purpose,
        string $name,
        string $productId,
        string $region,
        ?string $imageId,
        array $payload,
        array $keys,
        ?int $hostingNodeId = null,
        ?int $emailServerId = null,
        ?string $mailDbPassword = null,
        ?User $actor = null,
    ): ContaboInfrastructureProvision {
        return ContaboInfrastructureProvision::create([
            'purpose' => $purpose,
            'status' => ContaboInfrastructureProvision::STATUS_PENDING,
            'name' => $name,
            'contabo_product_id' => $productId,
            'region' => $region,
            'image_id' => $imageId ?: null,
            'completion_token' => Str::random(48),
            'payload' => $payload,
            'log' => [],
            'ssh_public_key' => $keys['public_key'],
            'ssh_private_key' => $keys['private_key'],
            'generated_mail_db_password' => $mailDbPassword,
            'hosting_node_id' => $hostingNodeId,
            'email_server_id' => $emailServerId,
            'created_by' => $actor?->id,
        ]);
    }

    private function assertEnabled(): void
    {
        if (! $this->isEnabled()) {
            throw new \RuntimeException('Contabo infrastructure provisioning is not configured. Set CONTABO_* credentials in .env.');
        }
    }
}