Param(
    [int] $Privacy = 1,
    [int] $Security = 0,
    [string] $DataFile = ".\data.json",
    [string] $TexFile = ".\telemetry.tex",
    [string] $LogFile = $null,
    [switch] $Verbose
)
# Powershell does not catch "non terminating errors" -> make all exceptons "terminating"
$ErrorActionPreference = "Stop"

function logV([string] $text)
{
    if ($Verbose)
    {
        log($text)
    }
}
function log([string] $text)
{
    Write-Host $text
    if ("" -ne $LogFile)
    {
        Write-Output $text | Out-File -Append -FilePath $LogFile
    }
}

function check_key($key)
{
    $message = "`nTesting key: $( $key.path )\$( $key.name )`n"
    $out = ""
    Try
    {
        $entry = Get-ItemProperty -Path $key.path -Name $key.name
        $value = $entry.($key.name)
        if ($value -eq $key.value)
        {
            logV("$message Correct value set: $value")
            return $out
        }
        else
        {
            log("$message Incorrect value: $value; Expected: $( $key.value )")
        }
    }
    Catch [System.Security.SecurityException]
    {
        log("$message Access denied, try again as administrator")
        return $out
    }
    Catch [System.Management.Automation.ItemNotFoundException]
    {
        log("$message Key Not Found")
        $value = $null
    }
    Catch [System.Management.Automation.PSArgumentException]
    {
        log("$message Subkey not found")
        $value = $null
    }
    Catch
    {
        log("$message Unexpected error")
        log($_.Exception)
        return $out
    }
    $out += $texItemTmpl -f$($key.path -replace "\\", "\\"), $( $key.name -replace "_", "\$&" ), `
                            $( $key.type -replace "_", "\$&" ), $key.value, $( if ($null -eq $value)
    {
        "Not set"
    }
    else
    {
        $value
    } )
    return $out
}

$user = [Security.Principal.WindowsIdentity]::GetCurrent();
$isAdmin = (New-Object Security.Principal.WindowsPrincipal $user).IsInRole([Security.Principal.WindowsBuiltinRole]::Administrator)
if (-not$isAdmin)
{
    logV("Started as a non admin")
    Write-Host "--------------------------------------------------------------------"
    Write-Host "!!! Your are running this Script as a non Admin !!!"
    Write-Host "Access to several registry keys might be denied"
    Write-Host "This will be shown in the resulting output"
    Write-Host "It is recommended to start this script as admin"
    Write-Host "--------------------------------------------------------------------"
    Write-Host "Press any key to continue ...`n"
    $host.UI.RawUI.ReadKey("NoEcho,IncludeKeyDown") | Out-Null
}

if (("" -ne $LogFile) -And (Test-Path $LogFile))
{
    logV("Clear old log file")
    Remove-Item $LogFile
}

logV("Reading JSON file from $DataFile")
$data = Get-Content -Encoding UTF8 -Raw -Path $DataFile | ConvertFrom-Json

$texOut = "\begin{landscape}`n\section{Windows 10 Telemetry}`n"
$texCatTmpl = "\multicolumn{{5}}{{l}}{{\textbf{{\textrm{{\ifgerman{{{0}}}{{{1}}}}}}}}}\\`n"
$texItemTmpl = "\url{{{0}}} & {1} & {2} & {3} & {4}\\`n"

ForEach ($scope in "Security", "Privacy")
{
    if ($( Get-Variable -Name $scope -ValueOnly ) -eq 0)
    {
        logV("`nSkipping scope '$scope'")
        continue
    }
    $texOut += "\subsection{$scope}`n\begin{sytable}[\ifgerman{Abweichende Registrierungsschlüssel}{Differing registry keys}]{X-l-l-l-l}
{ \ifgerman{Schlüsselpfad}{Key path} & Name & \ifgerman{Typ}{Type} & \ifgerman{Soll}{To-be} & \ifgerman{Ist}{As-is} }`n"
    ForEach ($cat in $data.$($scope.tolower() ))
    {
        if ($cat.level -gt $( Get-Variable -Name $scope -ValueOnly ))
        {
            logV("`nSkipping category '$( $cat.name.en )'")
            continue
        }
        logV("`nProcessing category '$( $cat.name.en )'")
        $first = $true
        # Processing keys
        ForEach ($key in $cat.keys)
        {
            $retValue = check_key($key)
            if ($retValue -eq "")
            {
                <# check local GPO as well:
            for "HKLM:\SOFTWARE\Policies\Microsoft\Windows\X"
            check "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Policies\X"#>
                if ( $key.path.Contains("SOFTWARE\Policies\Microsoft\Windows"))
                {
                    $key.path.Replace("Policies\Microsoft\Windows", "Microsoft\Windows\CurrentVersion\Policies")
                    $retValue = check_key($key)
                }
                if ($retValue -eq "")
                {
                    continue
                }
            }
            if ($first)
            {
                $texOut += $texCatTmpl -f $cat.name.de, $cat.name.en
                $first = $false
            }
            $texOut += $retValue
        }
    }
    $texOut += "\end{sytable}`n"
}
$texOut += "\end{landscape}`n`n"

Out-File -InputObject $texOut -FilePath $TexFile