Begin {
    # White list of Features On Demand V2 packages
    $WhiteListOnDemand = "NetFX3|Tools.Graphics.DirectX|Tools.DeveloperMode.Core|Language|Browser.InternetExplorer|ContactSupport|OneCoreUAP|Media.WindowsMediaPlayer|Hello.Face"

    # White list of appx packages to keep installed
    $WhiteListedApps = New-Object -TypeName System.Collections.ArrayList
    $WhiteListedApps.AddRange(@(
        "Microsoft.DesktopAppInstaller",
        "Microsoft.Messaging", 
        "Microsoft.MSPaint",
        "Microsoft.Windows.Photos",
        "Microsoft.StorePurchaseApp",
        "Microsoft.MicrosoftOfficeHub",
        "Microsoft.MicrosoftStickyNotes",
        "Microsoft.WindowsAlarms",
        "Microsoft.WindowsCalculator", 
        "Microsoft.WindowsSoundRecorder", 
        "Microsoft.WindowsStore"
    ))

    # Windows 10 version 1809
    $WhiteListedApps.AddRange(@(
        "Microsoft.ScreenSketch",
        "Microsoft.HEIFImageExtension",
        "Microsoft.VP9VideoExtensions",
        "Microsoft.WebMediaExtensions",
        "Microsoft.WebpImageExtension"
    ))

    # Windows 10 version 1903
    # No new apps
}
Process {
    # Functions
    function Write-LogEntry {
        param(
            [parameter(Mandatory=$true, HelpMessage="Value added to the RemovedApps.log file.")]
            [ValidateNotNullOrEmpty()]
            [string]$Value,
            [parameter(Mandatory=$false, HelpMessage="Name of the log file that the entry will written to.")]
            [ValidateNotNullOrEmpty()]
            [string]$FileName = "RemovedApps.log"
        )
        # Determine log file location
        $LogFilePath = Join-Path -Path $env:windir -ChildPath "Temp\$($FileName)"

        # Add value to log file
        try {
            Out-File -InputObject $Value -Append -NoClobber -Encoding Default -FilePath $LogFilePath -ErrorAction Stop
        }
        catch [System.Exception] {
            Write-Warning -Message "Unable to append log entry to $($FileName) file"
        }
    }

    # Initial logging
    Write-LogEntry -Value "Starting built-in AppxPackage, AppxProvisioningPackage and Feature on Demand V2 removal process"

    # Determine provisioned apps
    $AppArrayList = Get-AppxProvisionedPackage -Online | Select-Object -ExpandProperty DisplayName

    # Loop through the list of appx packages
    foreach ($App in $AppArrayList) {
        Write-LogEntry -Value "Processing appx package: $($App)"

        # If application name not in appx package white list, remove AppxPackage and AppxProvisioningPackage
        if (($App -in $WhiteListedApps)) {
            Write-LogEntry -Value "Skipping excluded application package: $($App)"
        }
        else {
            # Gather package names
            $AppPackageFullName = Get-AppxPackage -Name $App | Select-Object -ExpandProperty PackageFullName -First 1
            $AppProvisioningPackageName = Get-AppxProvisionedPackage -Online | Where-Object { $_.DisplayName -like $App } | Select-Object -ExpandProperty PackageName -First 1

            # Attempt to remove AppxPackage
            if ($AppPackageFullName -ne $null) {
                try {
                    Write-LogEntry -Value "Removing AppxPackage: $($AppPackageFullName)"
                    Remove-AppxPackage -Package $AppPackageFullName -ErrorAction Stop | Out-Null
                }
                catch [System.Exception] {
                    Write-LogEntry -Value "Removing AppxPackage '$($AppPackageFullName)' failed: $($_.Exception.Message)"
                }
            }
            else {
                Write-LogEntry -Value "Unable to locate AppxPackage for current app: $($App)"
            }

            # Attempt to remove AppxProvisioningPackage
            if ($AppProvisioningPackageName -ne $null) {
                try {
                    Write-LogEntry -Value "Removing AppxProvisioningPackage: $($AppProvisioningPackageName)"
                    Remove-AppxProvisionedPackage -PackageName $AppProvisioningPackageName -Online -ErrorAction Stop | Out-Null
                }
                catch [System.Exception] {
                    Write-LogEntry -Value "Removing AppxProvisioningPackage '$($AppProvisioningPackageName)' failed: $($_.Exception.Message)"
                }
            }
            else {
                Write-LogEntry -Value "Unable to locate AppxProvisioningPackage for current app: $($App)"
            }
        }
    }

    Write-LogEntry -Value "Starting Features on Demand V2 removal process"

    # Get Features On Demand that should be removed
    try {
        $OSBuildNumber = Get-WmiObject -Class "Win32_OperatingSystem" | Select-Object -ExpandProperty BuildNumber

        # Handle cmdlet limitations for older OS builds
        if ($OSBuildNumber -le "16299") {
            $OnDemandFeatures = Get-WindowsCapability -Online -ErrorAction Stop | Where-Object { $_.Name -notmatch $WhiteListOnDemand -and $_.State -like "Installed"} | Select-Object -ExpandProperty Name
        }
        else {
            $OnDemandFeatures = Get-WindowsCapability -Online -LimitAccess -ErrorAction Stop | Where-Object { $_.Name -notmatch $WhiteListOnDemand -and $_.State -like "Installed"} | Select-Object -ExpandProperty Name
        }

        foreach ($Feature in $OnDemandFeatures) {
            try {
                Write-LogEntry -Value "Removing Feature on Demand V2 package: $($Feature)"

                # Handle cmdlet limitations for older OS builds
                if ($OSBuildNumber -le "16299") {
                    Get-WindowsCapability -Online -ErrorAction Stop | Where-Object { $_.Name -like $Feature } | Remove-WindowsCapability -Online -ErrorAction Stop | Out-Null
                }
                else {
                    Get-WindowsCapability -Online -LimitAccess -ErrorAction Stop | Where-Object { $_.Name -like $Feature } | Remove-WindowsCapability -Online -ErrorAction Stop | Out-Null
                }
            }
            catch [System.Exception] {
                Write-LogEntry -Value "Removing Feature on Demand V2 package failed: $($_.Exception.Message)"
            }
        }    
    }
    catch [System.Exception] {
        Write-LogEntry -Value "Attempting to list Feature on Demand V2 packages failed: $($_.Exception.Message)"
    }

    # Complete
    Write-LogEntry -Value "Completed built-in AppxPackage, AppxProvisioningPackage and Feature on Demand V2 removal process"
}