Allow storing settings using the context

scripts/Windows/Scripts/Context.ps1

@@ -4,11 +4,17 @@ class Context {
     [string]$BackupName;
     [string]$UserName;
     [string]$AdminName = "Admin";
+    [string]$ConfigRoot = "HKLM:\Software\PortValhalla";
     [string]$RunOnceName = "PortValhalla";
+
+    [string] ProjectRoot() {
+        return Resolve-Path (Join-Path $PSScriptRoot ".." ".." "..");
+    }
+
     [string] BackupRoot() {
         if (-not $this.RootDir)
         {
-            return Join-Path $PSScriptRoot ".." ".." ".." "backup" $this.BackupName;
+            return Join-Path $this.ProjectRoot() $this.BackupName;
         }
         else
         {
@@ -16,6 +22,28 @@ class Context {
         }
     }
 
+    [Microsoft.Win32.RegistryKey] EnsureConfigKey() {
+        if (-not (Test-Path $this.ConfigRoot)) {
+            New-Item $this.ConfigRoot;
+        }
+
+        return Get-Item $this.ConfigRoot;
+    }
+
+    [void] Set([string] $key, $value, [Microsoft.Win32.RegistryValueKind] $type) {
+        $configKey = $this.EnsureConfigKey();
+        $configKey.SetValue($key, $value, $type);
+    }
+
+    [object] Get([string] $key) {
+        $configKey = $this.EnsureConfigKey();
+        if ($configKey.GetValueNames().Contains($key)) {
+            return $configKey.GetValue($key);
+        } else {
+            return $null;
+        }
+    }
+
     [string] ArchivePath($name) {
         return Join-Path $this.BackupRoot() "$name.7z";
     }