PortValhalla/scripts/Windows/Scripts/AppAssociations.ps1

$null = New-Module {
    class AppAssociations {
        static $defaultAssociationsSelector = "/DefaultAssociations";
        static $associationSelector = "./Association";

        static [string] GetSelector([string] $identifier) {
            return "$([AppAssociations]::associationSelector)[@Identifier='$identifier']";
        }

        static [xml] GetAppAssociations() {
            [xml] $associations = [xml]::new();
            $associations.LoadXml(((DISM /Online /Get-DefaultAppAssociations) | Select-Object -Skip 6 | Select-Object -SkipLast 2 | Out-String));
            return $associations;
        }

        static SetAssociation([string] $identifier, [string] $progId, [string] $applicationName) {
            $document = [AppAssociations]::GetAppAssociations();
            $associations = $document.SelectSingleNode([AppAssociations]::defaultAssociationsSelector);

            [System.Xml.XmlNode] $association = $null;
            $candidates = $associations.SelectNodes([AppAssociations]::GetSelector($identifier));

            if ($candidates.Count -eq 1) {
                $association = $candidates[0];
            } else {
                $association = ($associations.SelectNodes([AppAssociations]::associationSelector) | Select-Object -Last 1).CloneNode($true);
                $association.Identifier = $identifier;
                $association = $associations.AppendChild($association);
            }

            $association.ProgId = $progId;
            $association.ApplicationName = $applicationName;
            [AppAssociations]::SaveAssociations($document);
        }

        static SaveAssociations([xml] $document) {
            $associations = $document.SelectSingleNode([AppAssociations]::defaultAssociationsSelector);
            $defaultAssociations = $associations.SelectNodes([AppAssociations]::associationSelector);
            $defaultAssociations | ForEach-Object { $associations.RemoveChild($_); } | Sort-Object -Property "Identifier" | ForEach-Object { $associations.AppendChild($_); };

            $configFile = New-TemporaryFile;
            $writerSettings = [System.Xml.XmlWriterSettings]::new();
            $writerSettings.Indent = $true;
            $writerSettings.Encoding = [System.Text.UTF8Encoding]::new();
            $writer = [System.Xml.XmlWriter]::Create($configFile.FullName, $writerSettings);
            $document.Save($writer);
            $writer.Dispose();
            DISM /Online "/Import-DefaultAppAssociations:$($configFile.FullName)";
            Remove-Item $configFile;
        }
    }

    function Set-DefaultAppAssociation {
        param (
            [string] $Identifier,
            [string] $ProgId,
            [string] $ApplicationName
        )

        [AppAssociations]::SetAssociation($Identifier, $ProgId, $ApplicationName);
    }
}