# Test-RegExport.ps1
#
# Exercises Backup-NtlarsSettings.ps1's Export-DncToReg against MOCK registry
# keys, so the formatting can be verified on a machine with no registry (a
# Linux dev box running PowerShell Core, for instance).
#
# Why this exists: bad escaping or a wrong dword format produces a .reg that
# looks fine, imports without complaint, and only reveals itself when a tech
# restores a machine and the settings are subtly wrong. That failure is far too
# late and far too expensive, so the formatting gets tested away from the bay.
#
# Writes the generated .reg to -OutFile so the ShopDB-side Python codec can
# parse it in the same run and confirm both ends agree.
#
#   pwsh -NoProfile -File Test-RegExport.ps1 -OutFile /tmp/mock.reg

param(
    [string]$OutFile = './mock-export.reg'
)

$ErrorActionPreference = 'Stop'

. (Join-Path $PSScriptRoot 'Backup-NtlarsSettings.ps1')

function New-MockKey {
    <#
        A stand-in for a Microsoft.Win32.RegistryKey. PowerShell is duck-typed,
        so Export-DncToReg only needs .Name, .GetValueNames(), .GetValueKind()
        and .GetValue().
    #>
    param(
        [Parameter(Mandatory)][string]$Name,
        [Parameter(Mandatory)][hashtable]$Values   # name -> @{ Kind; Data }
    )
    $key = [pscustomobject]@{ Name = $Name; _values = $Values }
    $key | Add-Member ScriptMethod GetValueNames { $this._values.Keys } -Force
    $key | Add-Member ScriptMethod GetValueKind {
        param($n) $this._values[$n].Kind } -Force
    $key | Add-Member ScriptMethod GetValue {
        param($n) $this._values[$n].Data } -Force
    return $key
}

$root = 'HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\GE Aircraft Engines\DNC'

$keys = @(
    New-MockKey -Name $root -Values @{
        'COMPUTERNAME' = @{ Kind = 'String'; Data = 'GGBX0NH3ESF' }
    }
    New-MockKey -Name "$root\General" -Values @{
        'MachineNo' = @{ Kind = 'String'; Data = '3204' }
        'Cnc'       = @{ Kind = 'String'; Data = 'OKUMA' }
        'HostType'  = @{ Kind = 'String'; Data = 'WILM' }
    }
    New-MockKey -Name "$root\Btr" -Values @{
        'BTR Rate'    = @{ Kind = 'String'; Data = '300' }
        'Auto Rewind' = @{ Kind = 'String'; Data = 'YES' }
        'CmntLag'     = @{ Kind = 'DWord';  Data = 0 }
        'BigCount'    = @{ Kind = 'DWord';  Data = 4294967295 }
    }
    # The nasty cases: characters that must be escaped, and the wide/binary
    # value kinds that do not occur in the current corpus but are legal.
    New-MockKey -Name "$root\EdgeCases" -Values @{
        'Path With Backslash' = @{ Kind = 'String'; Data = 'C:\Program Files\GE' }
        'Has "Quotes"'        = @{ Kind = 'String'; Data = 'say "hi"' }
        'Empty'               = @{ Kind = 'String'; Data = '' }
        'Expanded'            = @{ Kind = 'ExpandString'; Data = '%SystemRoot%\dnc' }
        'Multi'               = @{ Kind = 'MultiString'; Data = @('one','two') }
        'Blob'                = @{ Kind = 'Binary'; Data = [byte[]](1,2,255) }
        'Big'                 = @{ Kind = 'QWord'; Data = [uint64]1234567890123 }
    }
)

$text = Export-DncToReg -Keys $keys

# UTF-16LE + BOM, matching what the real script posts.
$bytes = [byte[]](0xFF, 0xFE) + [Text.Encoding]::Unicode.GetBytes($text)
[IO.File]::WriteAllBytes($OutFile, $bytes)

Write-Host "Wrote $OutFile ($($bytes.Length) bytes)"
Write-Host '--- first lines ---'
($text -split "`r`n" | Select-Object -First 12) | ForEach-Object { Write-Host "  $_" }