# Set-MachineNumber.ps1 - Update UDC + eDNC machine number on a Standard shopfloor PC
#
# Purpose:
#   Both UDC and eDNC use the same per-machine identifier ("Workstation Number" /
#   "Machine Number"). On Standard PCs imaged via PXE preinstall, both are installed
#   with a placeholder. When the PC is brought to its physical machine and assigned
#   a real number, this helper updates both apps in one step.
#
# Persistence locations updated:
#   1. UDC:  C:\ProgramData\UDC\udc_settings.json  (GeneralSettings.MachineNumber)
#   2. eDNC: HKLM:\SOFTWARE\WOW6432Node\GE Aircraft Engines\DNC\General\MachineNo
#
# After updating, kills any running UDC.exe and relaunches it with the new args
# so the in-memory state matches the persisted value.
#
# Run as SupportUser (admin). Requires write access to ProgramData and HKLM.

Add-Type -AssemblyName Microsoft.VisualBasic
Add-Type -AssemblyName System.Windows.Forms

function Get-SiteConfig {
    $configPath = 'C:\Enrollment\site-config.json'
    if (-not (Test-Path -LiteralPath $configPath)) {
        Write-Host "site-config.json not found - using defaults" -ForegroundColor DarkGray
        return $null
    }
    try {
        return (Get-Content -LiteralPath $configPath -Raw -ErrorAction Stop | ConvertFrom-Json)
    } catch {
        Write-Warning "Failed to parse site-config.json: $_"
        return $null
    }
}
$siteConfig = Get-SiteConfig

$udcSettingsPath = "C:\ProgramData\UDC\udc_settings.json"
$udcExePath      = "C:\Program Files\UDC\UDC.exe"
$ednRegPath      = "HKLM:\SOFTWARE\WOW6432Node\GE Aircraft Engines\DNC\General"
$site            = if ($siteConfig) { $siteConfig.siteName } else { 'West Jefferson' }

# --- Read current values for display ---
$currentUdc  = $null
$currentEdnc = $null

if (Test-Path $udcSettingsPath) {
    try {
        $json = Get-Content $udcSettingsPath -Raw | ConvertFrom-Json
        $currentUdc = $json.GeneralSettings.MachineNumber
    } catch {
        $currentUdc = "(unreadable: $_)"
    }
}

if (Test-Path $ednRegPath) {
    try {
        $currentEdnc = (Get-ItemProperty -Path $ednRegPath -Name MachineNo -ErrorAction Stop).MachineNo
    } catch {
        $currentEdnc = $null
    }
}

# --- Show prompt with current state ---
$promptLines = @()
$promptLines += "Current UDC machine number:  $(if ($currentUdc)  { $currentUdc }  else { '(not set)' })"
$promptLines += "Current eDNC machine number: $(if ($currentEdnc) { $currentEdnc } else { '(not set)' })"
$promptLines += ""
$promptLines += "Enter the new Machine Number for this PC:"
$prompt = $promptLines -join "`n"

$new = [Microsoft.VisualBasic.Interaction]::InputBox($prompt, "Set Machine Number", "")

if ([string]::IsNullOrWhiteSpace($new)) {
    Write-Host "Cancelled."
    exit 0
}

$new = $new.Trim()

# --- Validate: digits only (loosen if you need alphanumerics) ---
if ($new -notmatch '^\d+$') {
    [System.Windows.Forms.MessageBox]::Show(
        "Machine number must be digits only.`n`nYou entered: '$new'",
        "Invalid Machine Number",
        [System.Windows.Forms.MessageBoxButtons]::OK,
        [System.Windows.Forms.MessageBoxIcon]::Error
    ) | Out-Null
    exit 1
}

$results = @()

# --- 1. Stop UDC.exe before editing its JSON (avoid stale shutdown write) ---
$udcProcs = Get-Process UDC -ErrorAction SilentlyContinue
if ($udcProcs) {
    Write-Host "Stopping UDC.exe ($($udcProcs.Count) instance(s))..."
    $udcProcs | ForEach-Object {
        try {
            $_.Kill()
            $_.WaitForExit(5000) | Out-Null
        } catch {
            Write-Warning "Failed to stop UDC.exe (PID $($_.Id)): $_"
        }
    }
    Start-Sleep -Seconds 1
}

# --- 2. Update UDC settings JSON ---
if (Test-Path $udcSettingsPath) {
    try {
        $json = Get-Content $udcSettingsPath -Raw | ConvertFrom-Json
        $json.GeneralSettings.MachineNumber = $new
        $json | ConvertTo-Json -Depth 99 | Set-Content -Path $udcSettingsPath -Encoding UTF8
        Write-Host "UDC: $currentUdc -> $new"
        $results += "UDC updated to $new"
    } catch {
        Write-Warning "Failed to update UDC settings: $_"
        $results += "UDC FAILED: $_"
    }
} else {
    Write-Warning "UDC settings file not found at $udcSettingsPath. Run UDC.exe at least once to initialize."
    $results += "UDC: settings file missing (run UDC.exe once first)"
}

# --- 3. Update eDNC MachineNo registry value ---
if (Test-Path $ednRegPath) {
    try {
        Set-ItemProperty -Path $ednRegPath -Name MachineNo -Value $new -Type String -Force
        Write-Host "eDNC: $currentEdnc -> $new"
        $results += "eDNC updated to $new"
    } catch {
        Write-Warning "Failed to update eDNC MachineNo: $_"
        $results += "eDNC FAILED: $_"
    }
} else {
    Write-Warning "eDNC registry key not found at $ednRegPath. Is eDNC installed?"
    $results += "eDNC: registry key missing (eDNC not installed?)"
}

# --- 4. Relaunch UDC.exe with new args (if installed) ---
if (Test-Path $udcExePath) {
    try {
        Start-Process -FilePath $udcExePath -ArgumentList @("-site", "`"$site`"", "-machine", $new)
        Write-Host "UDC.exe relaunched."
    } catch {
        Write-Warning "Failed to relaunch UDC.exe: $_"
    }
}

# --- 5. Show summary ---
$summary = ($results -join "`n") + "`n`nTo apply eDNC changes, restart any running DncMain.exe."
[System.Windows.Forms.MessageBox]::Show(
    $summary,
    "Set Machine Number - Done",
    [System.Windows.Forms.MessageBoxButtons]::OK,
    [System.Windows.Forms.MessageBoxIcon]::Information
) | Out-Null