Set-StrictMode -Version 2.0
$ErrorActionPreference = "Stop"

$sshCommand = Get-Command ssh.exe -ErrorAction SilentlyContinue
if (-not $sshCommand) {
    Write-Error "OpenSSH Client is not installed. Add it from Windows Optional Features."
    return
}

$rawPort = Read-Host "Local port"
$localPort = 0
if (-not [int]::TryParse($rawPort, [ref]$localPort) -or $localPort -lt 1 -or $localPort -gt 65535) {
    Write-Error "The local port must be a number from 1 to 65535."
    return
}

$portIsOpen = $false
foreach ($address in @("127.0.0.1", "::1")) {
    $client = New-Object System.Net.Sockets.TcpClient
    try {
        $connectTask = $client.ConnectAsync($address, $localPort)
        if ($connectTask.Wait(1500) -and $client.Connected) {
            $portIsOpen = $true
            break
        }
    }
    catch {
        # Try the other loopback address before reporting failure.
    }
    finally {
        $client.Dispose()
    }
}

if (-not $portIsOpen) {
    Write-Error "Nothing is listening on localhost:$localPort. Start the local development server first."
    return
}

$knownHostLine = "[terminal.sudorgin.com]:22222 ssh-ed25519 AAAAC3NzaC1lZDI1NTE5AAAAIAdWHOoQ80tqid08wdBMh+q5pRz31lULb+Hg6wIQVczN"
$knownHostsPath = Join-Path ([System.IO.Path]::GetTempPath()) ("sudorgin-dev-tunnel-" + [guid]::NewGuid().ToString("N") + ".known_hosts")
$utf8NoBom = New-Object System.Text.UTF8Encoding($false)
[System.IO.File]::WriteAllText($knownHostsPath, $knownHostLine + [Environment]::NewLine, $utf8NoBom)

$sshArguments = @(
    "-p", "22222",
    "-R", "9999:localhost:$localPort",
    "-o", "ExitOnForwardFailure=yes",
    "-o", "ServerAliveInterval=30",
    "-o", "ServerAliveCountMax=3",
    "-o", "TCPKeepAlive=yes",
    "-o", "PubkeyAuthentication=no",
    "-o", "PreferredAuthentications=keyboard-interactive,password",
    "-o", "StrictHostKeyChecking=yes",
    "-o", "UserKnownHostsFile=$knownHostsPath",
    "-N",
    "creator@terminal.sudorgin.com"
)

Write-Host "Publishing localhost:$localPort as https://dev.sudorgin.com" -ForegroundColor Cyan
Write-Host "SSH will ask for the server password. Keep this window open; press Ctrl+C to stop." -ForegroundColor Yellow

try {
    & $sshCommand.Source @sshArguments
    if ($LASTEXITCODE -ne 0) {
        Write-Error "SSH exited with code $LASTEXITCODE. Another tunnel may already be using the public endpoint."
    }
}
finally {
    Remove-Item -LiteralPath $knownHostsPath -Force -ErrorAction SilentlyContinue
}