<?php

namespace App\Services\Hosting;

use App\Models\Domain;
use App\Models\HostingAccount;
use App\Models\HostingNode;
use App\Models\HostingPlan;
use App\Models\HostedSite;
use App\Models\ProvisioningJob;
use App\Models\User;
use App\Models\VpsInstance;
use App\Services\Hosting\Providers\ContaboProvider;
use App\Services\Hosting\Providers\SharedNodeProvider;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Log;
use Illuminate\Support\Str;

class HostingProvisioningService
{
    public function __construct(
        private ContaboProvider $contaboProvider,
        private SharedNodeProvider $sharedNodeProvider,
        private NodeCapacityService $nodeCapacityService,
        private HostingResourcePolicyService $resourcePolicyService,
    ) {}

    public function createSharedHostingAccount(User $user, HostingPlan $plan, string $domain): HostingAccount
    {
        return DB::transaction(function () use ($user, $plan, $domain) {
            // Find available node
            $node = $this->nodeCapacityService->findAvailableNode((int) $plan->disk_gb);
            $resourceLimits = $this->resourcePolicyService->defaultLimitsForProduct(null);

            if (!$node) {
                throw new \RuntimeException('No available hosting nodes for shared hosting');
            }

            // Generate unique username
            $username = $this->generateUsername($user, $domain);

            // Create account record
            $account = HostingAccount::create([
                'user_id' => $user->id,
                'hosting_plan_id' => $plan->id,
                'hosting_node_id' => $node->id,
                'username' => $username,
                'primary_domain' => $domain,
                'type' => HostingAccount::TYPE_SHARED,
                'status' => HostingAccount::STATUS_PROVISIONING,
                'allocated_disk_gb' => (int) $plan->disk_gb,
                'cpu_limit_percent' => $resourceLimits['cpu_limit_percent'],
                'memory_limit_mb' => $resourceLimits['memory_limit_mb'],
                'process_limit' => $resourceLimits['process_limit'],
                'io_limit_mb' => $resourceLimits['io_limit_mb'],
                'inode_limit' => $resourceLimits['inode_limit'],
                'resource_status' => HostingAccount::RESOURCE_STATUS_ACTIVE,
                'php_version' => $plan->php_versions[0] ?? '8.2',
                'resource_limits' => [
                    'disk_gb' => $plan->disk_gb,
                    'bandwidth_gb' => $plan->bandwidth_gb,
                    'max_domains' => $plan->max_domains,
                    'max_databases' => $plan->max_databases,
                    'cpu_limit_percent' => $resourceLimits['cpu_limit_percent'],
                    'memory_limit_mb' => $resourceLimits['memory_limit_mb'],
                    'process_limit' => $resourceLimits['process_limit'],
                    'io_limit_mb' => $resourceLimits['io_limit_mb'],
                    'inode_limit' => $resourceLimits['inode_limit'],
                ],
            ]);

            // Create provisioning job
            $job = ProvisioningJob::create([
                'type' => 'create_shared_account',
                'provisionable_type' => HostingAccount::class,
                'provisionable_id' => $account->id,
                'provider' => 'shared_node',
                'status' => ProvisioningJob::STATUS_PENDING,
                'payload' => [
                    'username' => $username,
                    'domain' => $domain,
                    'node_id' => $node->id,
                ],
            ]);

            // Dispatch async provisioning
            dispatch(function () use ($account, $job, $node, $domain) {
                $this->provisionSharedAccount($account, $job, $node, $domain);
            })->afterCommit();

            return $account;
        });
    }

    public function createVpsInstance(User $user, HostingPlan $plan, array $config): VpsInstance
    {
        return DB::transaction(function () use ($user, $plan, $config) {
            $hostname = $config['hostname'] ?? 'vps-' . Str::random(8) . '.ladill.com';

            $instance = VpsInstance::create([
                'user_id' => $user->id,
                'hosting_plan_id' => $plan->id,
                'name' => $config['name'] ?? $hostname,
                'hostname' => $hostname,
                'provider' => 'contabo',
                'region' => $config['region'] ?? 'EU',
                'image' => $config['image'] ?? 'afecbb85-e2fc-46f0-9684-b46b1faf00bb',
                'cpu_cores' => $plan->cpu_cores,
                'ram_mb' => $plan->ram_mb,
                'disk_gb' => $plan->disk_gb,
                'status' => 'provisioning',
                'ssh_public_key' => $config['ssh_public_key'] ?? null,
                'tags' => $config['tags'] ?? [],
            ]);

            $job = ProvisioningJob::create([
                'type' => 'create_vps_instance',
                'provisionable_type' => VpsInstance::class,
                'provisionable_id' => $instance->id,
                'provider' => 'contabo',
                'status' => ProvisioningJob::STATUS_PENDING,
                'payload' => [
                    'product_id' => $plan->contabo_product_id,
                    'region' => $config['region'] ?? 'EU',
                    'image' => $config['image'] ?? 'afecbb85-e2fc-46f0-9684-b46b1faf00bb',
                    'ssh_keys' => $config['ssh_keys'] ?? [],
                    'user_data' => $config['user_data'] ?? null,
                ],
            ]);

            dispatch(function () use ($instance, $job, $config, $plan) {
                $this->provisionVpsInstance($instance, $job, $config, $plan);
            })->afterCommit();

            return $instance;
        });
    }

    public function addSiteToAccount(HostingAccount $account, string $domain, string $type = 'addon'): HostedSite
    {
        $docRoot = "/home/{$account->username}/public_html/{$domain}";

        $site = HostedSite::create([
            'hosting_account_id' => $account->id,
            'domain' => $domain,
            'document_root' => $docRoot,
            'type' => $type,
            'status' => 'pending',
            'php_version' => $account->php_version,
        ]);

        try {
            $this->sharedNodeProvider->addSite($site);
            $site->update(['status' => 'active']);
            
            // Sync to Domain registry
            $this->syncToDomainRegistry($account, $domain, $site);
        } catch (\Exception $e) {
            $site->update(['status' => 'disabled']);
            throw $e;
        }

        return $site;
    }

    /**
     * Sync hosting site to unified Domain registry
     */
    private function syncToDomainRegistry(HostingAccount $account, string $host, HostedSite $site): void
    {
        try {
            $domain = Domain::where('host', $host)->first();
            
            if ($domain) {
                // Update existing domain to add hosting
                $domain->update([
                    'hosting_account_id' => $account->id,
                    'source' => $domain->email_domain_id ? 'hosting_email' : 'hosting',
                    'onboarding_state' => $domain->onboarding_state === 'pending_ns' ? null : $domain->onboarding_state,
                ]);
            } else {
                // Create new domain entry
                Domain::create([
                    'user_id' => $account->user_id,
                    'host' => $host,
                    'hosting_account_id' => $account->id,
                    'source' => 'hosting',
                    'type' => 'custom',
                    'status' => 'verified',
                    'onboarding_state' => null,
                    'verified_at' => now(),
                ]);
            }
            
            Log::info('HostingProvisioningService: Synced to Domain registry', [
                'domain' => $host,
                'site_id' => $site->id,
            ]);
        } catch (\Throwable $e) {
            Log::warning('HostingProvisioningService: Failed to sync to Domain registry', [
                'domain' => $host,
                'error' => $e->getMessage(),
            ]);
        }
    }

    public function suspendAccount(HostingAccount $account, string $reason): bool
    {
        $result = $this->sharedNodeProvider->suspendAccount($account, $reason);

        if ($result) {
            $account->update([
                'status' => HostingAccount::STATUS_SUSPENDED,
                'suspension_reason' => $reason,
                'suspended_at' => now(),
            ]);
        }

        return $result;
    }

    public function unsuspendAccount(HostingAccount $account): bool
    {
        $result = $this->sharedNodeProvider->unsuspendAccount($account);

        if ($result) {
            $account->update([
                'status' => HostingAccount::STATUS_ACTIVE,
                'suspension_reason' => null,
                'suspended_at' => null,
            ]);
        }

        return $result;
    }

    public function terminateAccount(HostingAccount $account): bool
    {
        $result = $this->sharedNodeProvider->terminateAccount($account);

        if ($result) {
            $account->node?->decrementAccountCount();
            $account->update(['status' => HostingAccount::STATUS_TERMINATED]);
            $account->delete();
        }

        return $result;
    }

    public function controlVps(VpsInstance $instance, string $action): bool
    {
        return match ($action) {
            'start' => $this->contaboProvider->startInstance($instance->provider_instance_id),
            'stop' => $this->contaboProvider->stopInstance($instance->provider_instance_id),
            'reboot' => $this->contaboProvider->rebootInstance($instance->provider_instance_id),
            default => throw new \InvalidArgumentException("Unknown action: {$action}"),
        };
    }

    public function terminateVps(VpsInstance $instance): bool
    {
        if ($instance->provider_instance_id) {
            $this->contaboProvider->deleteInstance($instance->provider_instance_id);
        }

        $instance->update(['status' => 'terminated']);
        $instance->delete();

        return true;
    }

    private function provisionSharedAccount(HostingAccount $account, ProvisioningJob $job, HostingNode $node, string $domain): void
    {
        $job->markRunning();

        try {
            $result = $this->sharedNodeProvider->createAccount($account);

            $account->update([
                'status' => HostingAccount::STATUS_ACTIVE,
                'home_directory' => $result['home_directory'],
                'provisioned_at' => now(),
            ]);

            // Create primary site
            $site = HostedSite::create([
                'hosting_account_id' => $account->id,
                'domain' => $domain,
                'document_root' => $result['document_root'],
                'type' => 'primary',
                'status' => 'pending',
                'php_version' => $account->php_version,
            ]);

            $this->sharedNodeProvider->addSite($site);
            $site->update(['status' => 'active']);

            // Sync to Domain registry
            $this->syncToDomainRegistry($account, $domain, $site);

            $node->incrementAccountCount();

            $job->markCompleted([
                'username' => $result['username'],
                'home_directory' => $result['home_directory'],
                'initial_password' => $result['password'],
            ]);

            Log::info("Shared hosting account provisioned", [
                'account_id' => $account->id,
                'username' => $account->username,
            ]);

        } catch (\Exception $e) {
            Log::error("Shared hosting provisioning failed", [
                'account_id' => $account->id,
                'error' => $e->getMessage(),
            ]);

            $account->update(['status' => HostingAccount::STATUS_FAILED]);
            $job->markFailed($e->getMessage());
        }
    }

    private function provisionVpsInstance(VpsInstance $instance, ProvisioningJob $job, array $config, HostingPlan $plan): void
    {
        $job->markRunning();

        try {
            $rootPassword = Str::password(16);

            $result = $this->contaboProvider->createInstance([
                'product_id' => $plan->contabo_product_id,
                'name' => $instance->name,
                'region' => $config['region'] ?? 'EU',
                'image_id' => $config['image'] ?? 'afecbb85-e2fc-46f0-9684-b46b1faf00bb',
                'root_password' => $rootPassword,
                'ssh_keys' => $config['ssh_keys'] ?? [],
                'user_data' => $config['user_data'] ?? null,
            ]);

            $instance->update([
                'provider_instance_id' => $result['instance_id'],
                'ip_address' => $result['ip_address'],
                'ipv6_address' => $result['ipv6_address'],
                'datacenter' => $result['datacenter'],
                'status' => 'running',
                'power_status' => 'on',
                'root_password_encrypted' => encrypt($rootPassword),
                'provisioned_at' => now(),
            ]);

            $job->markCompleted([
                'instance_id' => $result['instance_id'],
                'ip_address' => $result['ip_address'],
                'root_password' => $rootPassword,
            ]);

            Log::info("VPS instance provisioned", [
                'instance_id' => $instance->id,
                'provider_id' => $result['instance_id'],
            ]);

        } catch (\Exception $e) {
            Log::error("VPS provisioning failed", [
                'instance_id' => $instance->id,
                'error' => $e->getMessage(),
            ]);

            $instance->update(['status' => 'failed']);
            $job->markFailed($e->getMessage());
        }
    }

    private function generateUsername(User $user, string $domain): string
    {
        $base = preg_replace('/[^a-z0-9]/', '', strtolower(explode('.', $domain)[0]));
        $base = substr($base, 0, 8) ?: 'user';

        $username = $base;
        $counter = 1;

        while (HostingAccount::where('username', $username)->exists()) {
            $username = $base . $counter;
            $counter++;
        }

        return $username;
    }
}