<?php

declare(strict_types=1);

namespace App\Services;

use Illuminate\Support\Facades\Log;

/**
 * VsphereHostSshService
 *
 * Executes pre-deployed PowerShell scripts on the vSphere Windows host
 * via native SSH (sshpass).  No phpseclib dependency.
 *
 * Scripts in C:/CLISave/ accept 5 positional params:
 *   VM_ID  NEW_PASSWORD  VCENTER_HOST  VCENTER_USER  VCENTER_PASSWORD
 *
 * Scripts only output "SUCCESS" or "FAIL".
 */
final class VsphereHostSshService
{
    private const HOST = '10.10.10.173';
    private const PORT = 22;
    private const USER = 'administrator';
    private const PASS = 'Thegioiso@123**$$8899TgTk2';

    private const SCRIPT_DIR     = 'C:\\CLISave'; // backslash required for Windows cmd.exe
    private const SCRIPT_LINUX   = 'changePasswordLinux.ps1';
    private const SCRIPT_WINDOWS = 'changePasswordWindows.ps1';

    private const CONNECT_TIMEOUT = 20;
    private const MAX_RETRIES     = 5;
    private const RETRY_DELAY     = 5;

    // ─────────────────────────────────────────────────────────────────────────

    /**
     * Run the OS-appropriate PS1 script on the vSphere host.
     *
     * @throws \RuntimeException on SSH failure
     */
    public function changePassword(
        string $vmId,
        string $newPassword,
        string $osFamily,
        string $vcenterHost,
        string $vcenterUser,
        string $vcenterPassword,
    ): string {
        $script = strtoupper($osFamily) === VmProvisionService::OS_WINDOWS
            ? self::SCRIPT_WINDOWS
            : self::SCRIPT_LINUX;

        // Remote Windows cmd.exe command — all args double-quoted
        $remoteCmd = sprintf(
            'cd %s && powershell -ExecutionPolicy Bypass -NonInteractive -File %s %s %s %s %s %s',
            self::SCRIPT_DIR,
            $script,
            $this->warg($vmId),
            $this->warg($newPassword),
            $this->warg($vcenterHost),
            $this->warg($vcenterUser),
            $this->warg($vcenterPassword),
        );

        Log::info('VsphereHostSshService: executing script', [
            'vm_id'        => $vmId,
            'script'       => $script,
            'vcenter_host' => $vcenterHost,
        ]);

        $output = $this->sshExec($remoteCmd);

        Log::info('VsphereHostSshService: script output', [
            'vm_id'  => $vmId,
            'output' => trim($output),
        ]);

        return $output;
    }

    // ─────────────────────────────────────────────────────────────────────────

    /**
     * Run a command on the vSphere SSH host via sshpass.
     * Retries up to MAX_RETRIES times on connection failure.
     *
     * @throws \RuntimeException
     */
    private function sshExec(string $remoteCmd): string
    {
        // Full native SSH command executed on local shell
        $sshCmd = sprintf(
            'sshpass -p %s ssh -o StrictHostKeyChecking=no -o ConnectTimeout=%d -p %d %s@%s %s 2>&1',
            escapeshellarg(self::PASS),
            self::CONNECT_TIMEOUT,
            self::PORT,
            escapeshellarg(self::USER),
            escapeshellarg(self::HOST),
            escapeshellarg($remoteCmd),
        );

        for ($attempt = 1; $attempt <= self::MAX_RETRIES; $attempt++) {
            $output = shell_exec($sshCmd);

            if ($output === null) {
                Log::warning('VsphereHostSshService: shell_exec returned null', [
                    'attempt' => $attempt,
                ]);
            } else {
                Log::info('VsphereHostSshService: SSH executed', ['attempt' => $attempt]);
                return $output;
            }

            if ($attempt < self::MAX_RETRIES) {
                sleep(self::RETRY_DELAY);
            }
        }

        throw new \RuntimeException(
            'SSH exec to ' . self::HOST . ' failed after ' . self::MAX_RETRIES . ' attempts',
        );
    }

    /**
     * Windows cmd.exe safe argument: wrap in double quotes, escape inner double quotes.
     * Password charset excludes " and % so wrapping is always safe.
     */
    private function warg(string $value): string
    {
        return '"' . str_replace('"', '\\"', $value) . '"';
    }
}