param([switch]$IgnoreSystem,[switch]$MissingOnly)

$local:currentSys = @('Always') + ([SystemName]::_GetValidValues('',$true,$true));

[MyConfig]::GetConfigPaths('mymodules',$false) |
    ForEach-Object { 
        $local:modules = $( Get-Content $_ | ConvertFrom-Json );
        $modules |
            Get-Member -MemberType NoteProperty | Select-Object -ExpandProperty Name |
            Where-Object {
                $IgnoreSystem -or ( $_ -in $currentSys )
            } |
            ForEach-Object { $modules."$_" }
    } |
    Where-Object {
        -not $MissingOnly -or
        $( try  {
            -not (Get-Module -ListAvailable $_ -ErrorAction stop)
            } catch { $true }
        )
    }