<?php

declare(strict_types=1);

namespace MageSail\Magesail\Model;

use Magento\Framework\App\Config\ScopeConfigInterface;
use Magento\Framework\Shell;
use Magento\Framework\Event\ManagerInterface as EventManager;
use Psr\Log\LoggerInterface;

/**
 * Start/stop tunnel processes per tunnel id; shared by admin Index and cron auto-restart.
 */
class TunnelManager
{
    private const XML_SCRIPT_PATH = 'magesail/settings/script_path';
    private const XML_NODE_BINARY = 'magesail/settings/node_binary';
    private const DEFAULT_SCRIPT_REL = 'app/code/MageSail/Magesail/scripts';

    public function __construct(
        private readonly Shell $shell,
        private readonly TunnelStatus $tunnelStatus,
        private readonly ScopeConfigInterface $scopeConfig,
        private readonly EventManager $eventManager,
        private readonly TunnelRegistry $tunnelRegistry,
        private readonly TunnelProcessPaths $tunnelProcessPaths,
        private readonly LoggerInterface $logger
    ) {
    }

    public function getScriptDir(): string
    {
        $configured = trim((string) $this->scopeConfig->getValue(self::XML_SCRIPT_PATH));
        if ($configured !== '') {
            return $configured;
        }
        return BP . '/' . self::DEFAULT_SCRIPT_REL;
    }

    /**
     * Executable for Node (config or "node" on PATH). Shell-escaped when embedded in commands.
     */
    private function getNodeBinaryForShell(): string
    {
        $configured = trim((string) $this->scopeConfig->getValue(self::XML_NODE_BINARY));
        if ($configured === '' || strpbrk($configured, "\r\n") !== false) {
            return escapeshellarg('node');
        }
        return escapeshellarg($configured);
    }

    /**
     * Starts the Node process for an existing registry tunnel (uses persisted port and secure flag).
     *
     * @return array{ok: bool, pid?: int, error?: string}
     */
    public function start(string $tunnelId): array
    {
        $tunnel = $this->tunnelRegistry->getById($tunnelId);
        if ($tunnel === null) {
            return ['ok' => false, 'error' => 'unknown_tunnel'];
        }
        $port = (int) ($tunnel['local_port'] ?? 0);
        $secure = (bool) ($tunnel['secure'] ?? false);
        if ($this->tunnelStatus->isRunning($tunnelId)) {
            return ['ok' => false, 'error' => 'already_running'];
        }
        if ($port < 1 || $port > 65535) {
            return ['ok' => false, 'error' => 'invalid_port'];
        }
        $dir = $this->tunnelProcessPaths->getVarTunnelDir();
        if (!\is_dir($dir) && !@mkdir($dir, 0775, true) && !\is_dir($dir)) {
            $this->logger->warning('MageSail: could not create var tunnel directory.');
            return ['ok' => false, 'error' => 'could_not_create_var_dir'];
        }
        $scriptDir = $this->getScriptDir();
        $startScript = rtrim($scriptDir, '/') . '/start-server.js';
        if (!\is_readable($startScript)) {
            $this->logger->warning('MageSail: start-server.js missing or not readable at {path}', ['path' => $startScript]);
            return ['ok' => false, 'error' => 'script_not_found', 'detail' => $startScript];
        }
        $nodeModules = rtrim($scriptDir, '/') . '/node_modules';
        if (!\is_dir($nodeModules)) {
            $this->logger->warning('MageSail: npm dependencies missing (no node_modules in scripts directory). Path: {path}', ['path' => $scriptDir]);
            return ['ok' => false, 'error' => 'node_modules_missing', 'detail' => $scriptDir];
        }
        $keyFile = $this->tunnelProcessPaths->getKeyFilePath($tunnelId);
        $logFile = $this->tunnelProcessPaths->getLogFilePath($tunnelId);
        $pidFile = $this->tunnelProcessPaths->getPidFilePath($tunnelId);
        $forwardHost = trim((string) ($tunnel['service_target_host'] ?? ''));
        if ($forwardHost === '') {
            $forwardHost = '127.0.0.1';
        }
        $jsArgs = json_encode([
            'port' => $port,
            'secure' => $secure,
            'forwardHost' => $forwardHost,
            'keyfile' => $keyFile,
            'logfile' => $logFile,
        ], JSON_THROW_ON_ERROR);
        $arg = escapeshellarg($jsArgs);
        $dirEscaped = escapeshellarg($scriptDir);
        $log = escapeshellarg($logFile);
        $nodeBin = $this->getNodeBinaryForShell();
        $fullCmd = "cd $dirEscaped && nohup $nodeBin start-server.js $arg > $log 2>&1 & echo \$!";
        try {
            $output = $this->shell->execute($fullCmd);
            $pid = (int) trim($output);
            if ($pid > 0) {
                file_put_contents($pidFile, (string) $pid);
                $this->eventManager->dispatch('magesail_tunnel_start_after', [
                    'tunnel_id' => $tunnelId,
                    'store_code' => $tunnel['store_code'] ?? '',
                    'pid' => $pid,
                    'port' => $port,
                    'secure' => $secure,
                ]);
                return ['ok' => true, 'pid' => $pid];
            }
            $this->logger->warning('MageSail: failed to capture PID after start. Output: {output}', ['output' => $output]);
            return ['ok' => false, 'error' => 'pid_capture_failed', 'detail' => $output];
        } catch (\Throwable $e) {
            $this->logger->error('MageSail: tunnel start exception: ' . $e->getMessage(), ['exception' => $e]);
            return ['ok' => false, 'error' => $e->getMessage()];
        }
    }

    /**
     * @return array{ok: bool, error?: string}
     */
    public function stop(string $tunnelId): array
    {
        $pidFile = $this->tunnelProcessPaths->getPidFilePath($tunnelId);
        $keyFile = $this->tunnelProcessPaths->getKeyFilePath($tunnelId);
        if (!\is_file($pidFile)) {
            return ['ok' => false, 'error' => 'not_running'];
        }
        $pid = (int) trim((string) file_get_contents($pidFile));
        if ($pid <= 0 || !$this->tunnelStatus->isProcessAlive($pid)) {
            @unlink($pidFile);
            if (\is_file($keyFile)) {
                @unlink($keyFile);
            }
            return ['ok' => false, 'error' => 'not_running'];
        }
        try {
            $this->shell->execute('kill %s', [$pid]);
            @unlink($pidFile);
            if (\is_file($keyFile)) {
                @unlink($keyFile);
            }
            $this->eventManager->dispatch('magesail_tunnel_stop_after', [
                'tunnel_id' => $tunnelId,
                'pid' => $pid,
            ]);
            return ['ok' => true];
        } catch (\Throwable $e) {
            $this->logger->error('MageSail: tunnel stop exception: ' . $e->getMessage(), ['exception' => $e]);
            return ['ok' => false, 'error' => $e->getMessage()];
        }
    }
}