param(
	$serverString,
	$exportPassword,
	$importPath
)

$servers = $serverString.Split(",");

$exportCertificateZipPath = "C:/temp/certificateExport.zip";
$script = {
    $password = $using:exportPassword;
    $exportPath = $using:exportCertificateZipPath;

	# Create the cert temp cert export directory for each server.
    $tempPath = "C:/temp/certificateExport";
    if(Test-Path $tempPath)
    {
        Remove-Item -Path $tempPath -Recurse -Force;
    }
    New-Item -Path $tempPath -ItemType Directory;

	# Export all certificates and compress them.
    try {
        Write-Host "Exporting Certificates to $tempPath";
        Export-Certificates -exportPassword $password -exportPath $tempPath;

        $zipPath = "$tempPath/*";
        Write-Host "Zipping certificates at $zipPath to archive $exportPath";
        Compress-Archive -Path $zipPath -DestinationPath $exportPath -Force | Out-Null;
    }
    catch {
        throw $_;
    }
    finally {
		# Clean up exported certs.
        if(Test-Path $tempPath)
        {
            Remove-Item -Path $tempPath -Recurse -Force;
        }
    }
}

try
{
    # Export all of the certificates on each server.
    Invoke-Command -ComputerName $servers -ScriptBlock $script;

    # Read all of the certificates back to the agent machine and unzip.
    $copyToAgentScript = {
        param($server)

        $certZipPath = Get-UncPath -filePath $using:exportCertificateZipPath -ComputerName $server;

        $serverImportDirectory = (Join-Path $using:importPath $server);
        $serverImportFile = (Join-Path $serverImportDirectory "certs.zip");
        if(Test-Path $certZipPath)
        {
            if(!(Test-Path $serverImportDirectory))
            {
                New-Item -Path $serverImportDirectory -ItemType Directory | Out-Null;
            }
            Write-Host "Copying $certZipPath to $serverImportFile";
            Move-Item -Path $certZipPath -Destination $serverImportFile -Force | Out-Null;

            Write-Host "Expanding archive $serverImportfile in $serverImportDirectory"
            Expand-Archive -Path $serverImportFile -DestinationPath $serverImportDirectory -Force;

            Remove-Item -Path $serverImportFile -Force;
        }
    }
    Invoke-Parallel -objects $servers -script $copyToAgentScript;
}
finally
{
    # Clean up the certificate export zip's on all of the servers if the process crashed.
    foreach($server in $servers)
    {
        $certZipPath = Get-UncPath -filePath $exportCertificateZipPath -ComputerName $server;
        if(Test-Path $certZipPath)
        {
            Write-Host "Cleaning up $certZipPath";
            Remove-Item -Path $certZipPath;
        }
    }
}