# Opens a port of this machine to the outside through a tunnel.
#
#   tools\tunnel.ps1 [-LocalPort 3389] [-Remote 3389] [-Tool bore|chisel]
#
# The tunnel runs here, the far side gets a port it can connect to, and the
# address to enter on the other machine is printed at the end.
#
# The usual use is the remote desktop: the port 3389 is forwarded and the
# remote desktop client connects to the address of the tunnel. The connection
# comes from the loopback, so the port of the remote desktop service does not
# have to be open on the local network.
#
# The bore server that serves ru.zern.cc listens on 7835 and holds the secret
# that the client and the server share. The old bat file on the desktop points
# at zernmc.ru, which is no longer reachable; ru.zern.cc is the one that works.
#
# ASCII only: PowerShell 5.1 reads a .ps1 without a byte order mark using the
# system ANSI code page.

param(
  [int]$LocalPort = 3389,
  [int]$Remote = 3389,
  [string]$Tool = 'bore',
  [string]$Host_ = 'ru.zern.cc',
  [string]$Secret = 'skyzernvintageforever',
  [string]$Bore = "$env:USERPROFILE\Desktop\bore.exe",
  [string]$Chisel = "$env:USERPROFILE\Downloads\chisel.exe"
)

$ErrorActionPreference = 'Stop'
$Root = Split-Path -Parent $PSScriptRoot
if (-not $Root) { $Root = 'G:\RustNotMC' }
$LogDir = Join-Path $Root 'logs'
New-Item -ItemType Directory -Force -Path $LogDir | Out-Null
$Log = Join-Path $LogDir 'tunnel.log'

# the tunnel that is already running goes first
Get-Process bore, chisel -ErrorAction SilentlyContinue | ForEach-Object {
  Write-Host "stopping the old tunnel (pid $($_.Id))"
  Stop-Process -Id $_.Id -Force -ErrorAction SilentlyContinue
}
Start-Sleep -Seconds 1

if ($Tool -eq 'chisel') {
  if (-not (Test-Path $Chisel)) { throw "no chisel at $Chisel" }
  $user = 'tunnel'
  $args = @(
    'client',
    "--server=ssh://$user`:$Secret@$Host_`:7835",
    '--remote-forward', "tcp:0.0.0.0`:$Remote`:127.0.0.1`:$LocalPort",
    '--keepalive-interval', '10'
  )
} else {
  if (-not (Test-Path $Bore)) { throw "no bore at $Bore" }
  $args = @('local', "$LocalPort", '--secret', $Secret, '--to', $Host_, '-p', "$Remote")
}
Write-Host "$Tool : $($args -join ' ')"

Remove-Item $Log, "$Log.err" -ErrorAction SilentlyContinue
$proc = Start-Process -FilePath $(if ($Tool -eq 'chisel') { $Chisel } else { $Bore }) `
  -ArgumentList $args -RedirectStandardOutput $Log -RedirectStandardError "$Log.err" `
  -WindowStyle Hidden -PassThru
Write-Host "tunnel pid $($proc.Id), log $Log"

# the tunnel says when it is up
$up = $false
for ($i = 0; $i -lt 30; $i++) {
  Start-Sleep -Milliseconds 500
  $text = (Get-Content $Log -Raw -ErrorAction SilentlyContinue) +
          (Get-Content "$Log.err" -Raw -ErrorAction SilentlyContinue)
  if ($text -match 'listening|Connected|connected|remote_port') { $up = $true; break }
}
if (-not $up) {
  Write-Host 'the tunnel did not say that it is up. The log:'
  Get-Content $Log, "$Log.err" -ErrorAction SilentlyContinue
  exit 1
}

Write-Host ''
Write-Host "  the local port $LocalPort is now $Host_`:$Remote"
Write-Host "  connect to that address; for the remote desktop it is"
Write-Host "  mstsc $Host_`:$Remote"
Write-Host ''
Get-Content $Log -ErrorAction SilentlyContinue