<?php

namespace App\Jobs;

use App\Models\TcpPort;
use App\Notifications\TcpPortAlert;
use Illuminate\Bus\Queueable;
use Illuminate\Contracts\Queue\ShouldQueue;
use Illuminate\Foundation\Bus\Dispatchable;
use Illuminate\Queue\InteractsWithQueue;
use Illuminate\Queue\SerializesModels;
use Illuminate\Support\Facades\Log;

class CheckTcpPort implements ShouldQueue
{
    use Dispatchable, InteractsWithQueue, Queueable, SerializesModels;

    /**
     * The number of times the job may be attempted.
     *
     * @var int
     */
    public $tries = 3;

    /**
     * The number of seconds the job can run before timing out.
     *
     * @var int
     */
    public $timeout = 30;

    /**
     * Create a new job instance.
     */
    public function __construct(
        public TcpPort $tcpPort
    ) {}

    /**
     * Execute the job.
     */
    public function handle(): void
    {
        try {
            $host = $this->extractHost($this->tcpPort->site->url);

            if (!$host) {
                Log::error('CheckTcpPort: Invalid URL', [
                    'tcp_port_id' => $this->tcpPort->id,
                    'site_id' => $this->tcpPort->site_id,
                    'url' => $this->tcpPort->site->url,
                ]);

                $this->tcpPort->update([
                    'is_open' => false,
                    'response_time_ms' => null,
                    'last_checked_at' => now(),
                ]);

                return;
            }

            $result = $this->checkPort($host, $this->tcpPort->port);

            $wasOpen = $this->tcpPort->is_open;

            $this->tcpPort->update([
                'is_open' => $result['is_open'],
                'response_time_ms' => $result['response_time'],
                'last_checked_at' => now(),
            ]);

            Log::info('CheckTcpPort: Check completed', [
                'tcp_port_id' => $this->tcpPort->id,
                'site_id' => $this->tcpPort->site_id,
                'host' => $host,
                'port' => $this->tcpPort->port,
                'is_open' => $result['is_open'],
                'response_time_ms' => $result['response_time'],
            ]);

            // Send notification if port status changed from open to closed
            if ($wasOpen === true && $result['is_open'] === false) {
                $this->tcpPort->site->user->notify(new TcpPortAlert(
                    $this->tcpPort,
                    'closed'
                ));

                Log::warning('CheckTcpPort: Port closed alert sent', [
                    'tcp_port_id' => $this->tcpPort->id,
                    'port' => $this->tcpPort->port,
                ]);
            }

            // Optionally send notification if port opened
            if ($wasOpen === false && $result['is_open'] === true) {
                $this->tcpPort->site->user->notify(new TcpPortAlert(
                    $this->tcpPort,
                    'opened'
                ));

                Log::info('CheckTcpPort: Port opened alert sent', [
                    'tcp_port_id' => $this->tcpPort->id,
                    'port' => $this->tcpPort->port,
                ]);
            }

        } catch (\Exception $e) {
            Log::error('CheckTcpPort: Failed', [
                'tcp_port_id' => $this->tcpPort->id,
                'error' => $e->getMessage(),
                'trace' => $e->getTraceAsString(),
            ]);

            $this->tcpPort->update([
                'is_open' => false,
                'response_time_ms' => null,
                'last_checked_at' => now(),
            ]);

            throw $e;
        }
    }

    /**
     * Extract host from URL.
     */
    protected function extractHost(string $url): ?string
    {
        $parsed = parse_url($url);
        return $parsed['host'] ?? null;
    }

    /**
     * Check if a TCP port is open.
     */
    protected function checkPort(string $host, int $port): array
    {
        $timeout = 5;
        $startTime = microtime(true);

        $errno = 0;
        $errstr = '';

        // Suppress warnings and capture errors
        $fp = @fsockopen($host, $port, $errno, $errstr, $timeout);

        $endTime = microtime(true);
        $responseTime = (int) round(($endTime - $startTime) * 1000);

        $isOpen = $fp !== false;

        if ($fp) {
            fclose($fp);
        }

        if (!$isOpen) {
            Log::debug('CheckTcpPort: Port check failed', [
                'host' => $host,
                'port' => $port,
                'errno' => $errno,
                'errstr' => $errstr,
                'response_time_ms' => $responseTime,
            ]);
        }

        return [
            'is_open' => $isOpen,
            'response_time' => $isOpen ? $responseTime : null,
            'error_code' => $errno,
            'error_message' => $errstr,
        ];
    }

    /**
     * Handle a job failure.
     */
    public function failed(\Throwable $exception): void
    {
        Log::error('CheckTcpPort: Job failed after all retries', [
            'tcp_port_id' => $this->tcpPort->id,
            'exception' => $exception->getMessage(),
        ]);
    }
}