<?php
declare(strict_types=1);

namespace MageSail\Magesail\Block\Adminhtml;

use Magento\Backend\Block\Template;
use MageSail\Magesail\Model\TunnelStatus;

class Tunnel extends Template
{
    private const LOG_TAIL_BYTES = 8192;
    private const LOG_TAIL_LINES = 40;

    public function __construct(
        Template\Context $context,
        private readonly TunnelStatus $tunnelStatus,
        array $data = []
    ) {
        parent::__construct($context, $data);
    }

    /**
     * @return array{running: bool, pid: int|null, key: string|null}
     */
    public function getTunnelStatus(): array
    {
        return $this->tunnelStatus->getStatus();
    }

    public function getConfigUrl(): string
    {
        return $this->getUrl('adminhtml/system_config/edit/section/magesail');
    }

    public function getStatusUrl(): string
    {
        return $this->getUrl('*/*/status', ['_query' => ['form_key' => $this->getFormKey()]]);
    }

    public function getFormKey(): string
    {
        return $this->formKey->getFormKey();
    }

    public function getLogFilePath(): string
    {
        return $this->tunnelStatus->getLogFilePath();
    }

    /**
     * @return string[]
     */
    public function getRecentLogLines(): array
    {
        $path = $this->tunnelStatus->getLogFilePath();
        if (!\is_readable($path)) {
            return [];
        }
        $size = filesize($path);
        if ($size === false || $size === 0) {
            return [];
        }
        $fp = fopen($path, 'rb');
        if ($fp === false) {
            return [];
        }
        $start = max(0, $size - self::LOG_TAIL_BYTES);
        fseek($fp, $start);
        if ($start > 0) {
            fgets($fp);
        }
        $chunk = stream_get_contents($fp) ?: '';
        fclose($fp);
        $lines = preg_split('/\R/', $chunk) ?: [];
        $lines = array_values(array_filter($lines, static fn ($l) => $l !== ''));
        if (\count($lines) > self::LOG_TAIL_LINES) {
            $lines = \array_slice($lines, -self::LOG_TAIL_LINES);
        }
        return $lines;
    }
}