AzureAuth Windows uninstall script

install/uninstall.ps1

@@ -0,0 +1,125 @@
+# Enable a default -Verbose flag for debug output.
+[CmdletBinding()]
+
+# Halt script execution at the first failed command.
+$script:ErrorActionPreference='Stop'
+
+$azureauthDefaultLocation = ([System.IO.Path]::Combine($Env:LOCALAPPDATA, "Programs", "AzureAuth"))
+
+if (![string]::IsNullOrEmpty($Env:AZUREAUTH_INSTALL_DIRECTORY) `
+        -And $Env:AZUREAUTH_INSTALL_DIRECTORY -ne $azureauthDefaultLocation) {
+    Write-Warning "Ignoring AZUREAUTH_INSTALL_DIRECTORY environment variable. Custom uninstallation locations are not supported."
+}
+
+function Uninstall {
+    Close-AzureauthInstances
+
+    $locations = Get-AzureauthsInPath
+    Remove-AzureauthDirectories $locations
+    Remove-FromPath $locations
+
+    Write-Output "Uninstalled AzureAuth!"
+}
+
+function Get-AzureauthsInPath {
+    $allLocations = [System.Collections.ArrayList]@()
+    $azureauthsInPath = (Get-Command -Name azureauth -ErrorAction SilentlyContinue -CommandType Application -All).Source
+
+    # Uninstallation is only supported from the default AzureAuth location.
+    # We warn the user of any custom locations that are listed in the PATH.
+    # Installations in custom locations that are not listed in PATH cannot
+    # be found and uninstalled.
+    # We still...
+    ForEach($az in $azureauthsInPath) {
+        $tempDirectory = (Get-Item $az).Directory.FullName
+        if (!$az.Contains($azureauthDefaultLocation)) {
+            Write-Warning "Additional installation found in ${tempDirectory}"
+        } else {
+            # We add the PATH location to the list and not the default location to later
+            # remove it from the PATH (default location is the whole parent folder).
+            $_ = $allLocations.Add($tempDirectory)
+        }
+    }
+
+    return $allLocations
+}
+
+function Remove-AzureauthDirectories {
+    param([System.Collections.ArrayList]$locationsToDelete)
+
+    ForEach ($location in $locationsToDelete) {
+        Remove-InstallationFolder $location
+    }
+
+    # We also delte AzureAuth parent folder
+    Remove-InstallationFolder $azureauthDefaultLocation
+}
+
+function Remove-InstallationFolder {
+    param ([string]$directory)
+
+    if (Test-Path -Path $directory) {
+        Write-Verbose "Removing installations at '${directory}'"
+        Remove-Item -Force -Recurse $directory
+    } else {
+        Write-Verbose "There were no installations found at '${directory}'"
+    }
+}
+
+function Remove-FromPath {
+    param ([System.Collections.ArrayList]$locationsToDelete)
+
+    $registryPath = 'Registry::HKEY_CURRENT_USER\Environment'
+    $currentPath = (Get-ItemProperty -Path $registryPath -Name PATH -ErrorAction SilentlyContinue).Path
+
+    # Reconstruct the $PATH without any azureauth directories.
+    $updatedPath = "";
+    if (($null) -ne $currentPath) {
+        $paths = $currentPath.Split(";")
+        $pathArr = @()
+        ForEach($path in $paths){
+            if(!$path.Equals("") -And ($locationsToDelete.Count -eq 0 -Or !$locationsToDelete.Contains($path))) {
+                $pathArr += "${path}"
+            }
+            elseif (!$path.Equals("")) {
+                Write-Verbose "Removing '${path}' from `$env:PATH"
+            }
+        }
+        $updatedPath = ($pathArr -join ";") + ";"
+    }
+
+    Set-ItemProperty -Path $registryPath -Name PATH -Value $updatedPath
+    Send-SettingChange
+}
+
+function Close-AzureauthInstances {
+    # Uninstall will fail if there are instances of AzureAuth running. 
+    # We suppress taskkill output here because this is a best effort attempt and we don't want the user to see its output.
+    # Here, Get-Process is used to first determine whether there is an existing azureauth process. If there is, kill the existing process first.
+    $ProcessCheck = Get-Process -Name azureauth -ErrorAction SilentlyContinue -ErrorVariable ProcessError
+    if ($null -ne $ProcessCheck) {
+        Write-Verbose "Stopping any currently running azureauth instances"
+        taskkill /f /im azureauth.exe 2>&1 | Out-Null
+
+        # After killing the process it is still possible for there there to be locks on the files it was using (including
+        # its own DLLs). The OS may take an indeterminate amount of time to clean those up, but so far we've observed 1
+        # second to be enough.
+        Start-Sleep -Seconds 1
+    }
+}
+
+# Send WM_SETTINGCHANGE after changing Environment variables.
+# Refer to https://gist.github.com/alphp/78fffb6d69e5bb863c76bbfc767effda
+function Send-SettingChange {
+    Add-Type -Namespace Win32 -Name NativeMethods -MemberDefinition @"
+    [DllImport("user32.dll", SetLastError = true, CharSet = CharSet.Auto)]
+    public static extern IntPtr SendMessageTimeout(IntPtr hWnd, uint Msg, UIntPtr wParam, string lParam, uint fuFlags, uint uTimeout, out UIntPtr lpdwResult);
+"@
+    $HWND_BROADCAST = [IntPtr] 0xffff;
+    $WM_SETTINGCHANGE = 0x1a;
+    $result = [UIntPtr]::Zero
+
+    [void] ([Win32.Nativemethods]::SendMessageTimeout($HWND_BROADCAST, $WM_SETTINGCHANGE, [UIntPtr]::Zero, "Environment", 2, 5000, [ref] $result))
+}
+
+Uninstall