# Remote Control Support - agent installer for Windows.
#
# Served from the hub, which substitutes HUB and TOKEN below before sending it:
#
#   irm https://support.freakma.com/install.ps1?token=TOKEN | iex
#
# Windows 7 / Server 2008 R2 ship PowerShell 2.0, which has no Invoke-RestMethod
# and no TLS 1.2, so those machines need the longer form instead:
#
#   powershell -c "[Net.ServicePointManager]::SecurityProtocol=3072; (New-Object Net.WebClient).DownloadString('https://support.freakma.com/install.ps1?token=TOKEN') | iex"
#
# Everything is written under %LOCALAPPDATA%. No administrator rights needed.

$ErrorActionPreference = 'Stop'

$Hub   = 'https://support.freakma.com'
$Token = ''

# .NET 3.5 has no Tls12 enum member, so the numeric value is the portable way.
# Harmless on modern Windows, essential on 2008 R2 (which also needs KB3154518).
try { [Net.ServicePointManager]::SecurityProtocol = 3072 } catch { }

function Write-Step { param($m) Write-Host "> $m" -ForegroundColor Cyan }
function Write-Warn { param($m) Write-Host "! $m" -ForegroundColor Yellow }
function Write-Die  { param($m) Write-Host "x $m" -ForegroundColor Red; exit 1 }

if (-not $Token) {
  Write-Die "no enrolment token. Open the invite link on this machine to get the full command."
}

$InstallDir = Join-Path $env:LOCALAPPDATA 'RemoteControlSupport'
$Config     = Join-Path $InstallDir 'config.json'
$TaskName   = 'RemoteControlSupportAgent'

if (-not (Test-Path $InstallDir)) { New-Item -ItemType Directory -Path $InstallDir | Out-Null }

$client = New-Object Net.WebClient

# ------------------------------------------------------------------ runtime

# Node 22 is preferred where it exists: smaller download, current runtime. Where
# it does not - which includes every Windows 7 and Server 2008 R2 box, since
# Node 14 dropped them - the self-contained executable carries its own Node 12.
$NodeMajor = 0
try { $NodeMajor = [int]((& node -p 'process.versions.node.split(".")[0]') 2>$null) } catch { }

if ($NodeMajor -ge 22) {
  Write-Step "using the Node.js $NodeMajor already installed here"
  $AgentPath = Join-Path $InstallDir 'agent.js'
  $client.DownloadFile("$Hub/download/agent.js", $AgentPath)
  $Exe  = 'node'
  $Args = @($AgentPath)
} else {
  Write-Step "no Node.js 22+ here - downloading the self-contained agent (about 30 MB)"
  $AgentPath = Join-Path $InstallDir 'rcs-agent.exe'
  $client.DownloadFile("$Hub/download/agent.exe", $AgentPath)
  $Exe  = $AgentPath
  $Args = @()
}

# ---------------------------------------------------------------------- vnc

# Advisory: the agent enrols fine without it, but a session cannot start until
# something is actually serving RFB on the loopback port.
$vncUp = $false
try {
  $probe = New-Object Net.Sockets.TcpClient
  $probe.Connect('127.0.0.1', 5900)
  $vncUp = $probe.Connected
  $probe.Close()
} catch { }
if (-not $vncUp) {
  Write-Warn "nothing is listening on 127.0.0.1:5900 - install TightVNC or UltraVNC and let it start on boot"
}

# ------------------------------------------------------------------ enrol

Write-Step "enrolling with $Hub"
& $Exe @($Args + @('enroll', "$Hub/enroll/$Token", '--config', $Config))
if ($LASTEXITCODE -ne 0) { Write-Die "enrolment failed - the link may have expired" }

# --------------------------------------------------------------- scheduled

# A Windows *service* runs in session 0 and cannot draw on the interactive
# desktop, so the "ask first" consent dialog would never appear. A logon task
# runs in the console session, where it can. schtasks.exe is used rather than
# Register-ScheduledTask because PowerShell 2.0 does not have that cmdlet.
Write-Step "registering a logon task so it starts with Windows"

if ($Args.Count -gt 0) {
  $run = '"' + $Exe + '" "' + $Args[0] + '" run --config "' + $Config + '"'
} else {
  $run = '"' + $Exe + '" run --config "' + $Config + '"'
}

& schtasks.exe /create /tn $TaskName /tr $run /sc onlogon /f | Out-Null
if ($LASTEXITCODE -ne 0) {
  Write-Warn "could not register the logon task - start the agent by hand with: $run"
} else {
  & schtasks.exe /run /tn $TaskName | Out-Null
}

Write-Host ""
Write-Host "Done. This machine is registered and should now appear in the console."
Write-Host "Installed in: $InstallDir"
Write-Host "Remove with:  schtasks /delete /tn $TaskName /f"