Implement data backup for Store app reinstall

Author: MCMrARM

MCLauncher/MainWindow.xaml.cs

@@ -12,6 +12,7 @@ namespace MCLauncher {
     using System.IO.Compression;
     using System.Threading;
     using Windows.Foundation;
+    using Windows.Management.Core;
     using Windows.Management.Deployment;
     using Windows.System;
     using WPFDataTypes;
@@ -99,6 +100,56 @@ private async Task DeploymentProgressWrapper(IAsyncOperationWithProgress<Deploym
             await src.Task;
         }
 
+        private string GetBackupMinecraftDataDir() {
+            string localAppData = Environment.GetFolderPath(Environment.SpecialFolder.LocalApplicationData);
+            string tmpDir = Path.Combine(localAppData, "TmpMinecraftLocalState");
+            return tmpDir;
+        }
+
+        private void BackupMinecraftDataForRemoval() {
+            var data = ApplicationDataManager.CreateForPackageFamily(MINECRAFT_PACKAGE_FAMILY);
+            string tmpDir = GetBackupMinecraftDataDir();
+            if (Directory.Exists(tmpDir)) {
+                Debug.WriteLine("BackupMinecraftDataForRemoval error: " + tmpDir + " already exists");
+                Process.Start("explorer.exe", tmpDir);
+                MessageBox.Show("The temporary directory for backing up MC data already exists. This probably means that we failed last time backing up the data. Please back the directory up manually.");
+                throw new Exception("Temporary dir exists");
+            }
+            Debug.WriteLine("Moving Minecraft data to: " + tmpDir);
+            Directory.Move(data.LocalFolder.Path, tmpDir);
+        }
+
+        private void RestoreMove(string from, string to) {
+            foreach (var f in Directory.EnumerateFiles(from)) {
+                string ft = Path.Combine(to, Path.GetFileName(f));
+                if (File.Exists(ft)) {
+                    if (MessageBox.Show("The file " + ft + " already exists in the destination.\nDo you want to replace it? The old file will be lost otherwise.", "Restoring data directory from previous installation", MessageBoxButton.YesNo) != MessageBoxResult.Yes)
+                        continue;
+                    File.Delete(ft);
+                }
+                File.Move(f, ft);
+            }
+            foreach (var f in Directory.EnumerateDirectories(from)) {
+                string tp = Path.Combine(to, Path.GetFileName(f));
+                if (!Directory.Exists(tp)) {
+                    if (File.Exists(tp) && MessageBox.Show("The file " + tp + " is not a directory. Do you want to remove it? The data from the old directory will be lost otherwise.", "Restoring data directory from previous installation", MessageBoxButton.YesNo) != MessageBoxResult.Yes)
+                        continue;
+                    Directory.CreateDirectory(tp);
+                }
+                RestoreMove(f, tp);
+            }
+        }
+
+        private void RestoreMinecraftDataFromReinstall() {
+            string tmpDir = GetBackupMinecraftDataDir();
+            if (!Directory.Exists(tmpDir))
+                return;
+            var data = ApplicationDataManager.CreateForPackageFamily(MINECRAFT_PACKAGE_FAMILY);
+            Debug.WriteLine("Moving backup Minecraft data to: " + data.LocalFolder.Path);
+            RestoreMove(tmpDir, data.LocalFolder.Path);
+            Directory.Delete(tmpDir, true);
+        }
+
         private async Task ReRegisterPackage(string gameDir) {
             foreach (var pkg in new PackageManager().FindPackages(MINECRAFT_PACKAGE_FAMILY)) {
                 if (pkg.InstalledLocation.Path == gameDir) {
@@ -107,8 +158,7 @@ private async Task ReRegisterPackage(string gameDir) {
                 }
                 Debug.WriteLine("Removing package: " + pkg.Id.FullName + " " + pkg.InstalledLocation.Path);
                 if (!pkg.IsDevelopmentMode) {
-                    if (MessageBox.Show("A non-Development Mode version is installed on this system. It will need to be removed in a way which does not preserve the data (including your saved worlds). Are you sure you want to continue?", "Warning", MessageBoxButton.YesNoCancel) != MessageBoxResult.Yes)
-                        return;
+                    BackupMinecraftDataForRemoval();
                     await DeploymentProgressWrapper(new PackageManager().RemovePackageAsync(pkg.Id.FullName, 0));
                 } else {
                     Debug.WriteLine("Package is in development mode");
@@ -121,6 +171,7 @@ private async Task ReRegisterPackage(string gameDir) {
             string manifestPath = Path.Combine(gameDir, "AppxManifest.xml");
             await DeploymentProgressWrapper(new PackageManager().RegisterPackageAsync(new Uri(manifestPath), null, DeploymentOptions.DevelopmentMode));
             Debug.WriteLine("App re-register done!");
+            RestoreMinecraftDataFromReinstall();
         }
 
         private void InvokeDownload(Version v) {