Convert MOF 2.0 to MOF 1.0 for PowerShell 4.0

Convert-Mof2ToMof1.psd1

param (
    $filename
)

$instanceReplace = @{}
$instanceRemove = @("ConfigurationName")
$metadataReplace = @{
    'Version="[0-9.]*"' = 'Version="1.0.0"'
}
$metadataRemove = @(
    "MinimumCompatibleVersion",
    "CompatibleVersionAdditionalProperties",
    "Name"
)

$inInstance = $false;
$isMetadata = $false;

Get-Content $filename | % {
    $line = $_
    if  ($line -match '^ *instance of ([^ ]*)') {
        $isMetadata = $Matches[1] -eq 'OMI_ConfigurationDocument'
        $isInstance = $true
    } elseif ($line -match '^ *}; *$') {
        $isInstance = $isMetadata = $false
    } elseif ($isInstance) {
        $removals = if ($isMetadata) { $metadataRemove } else { $instanceRemove }
        $replacements = if ($isMetadata) { $metadataReplace } else { $instanceReplace }
        if (($removals | ? { $line -match "^ *$_ *= *" }).Count -gt 0) {
            $line = $null
        } else {
            $replacements.Keys | % { $line = $line -replace $_, $metadataReplace[$_] }
        }
    }
    $line
}