modified settings services

CursorLang/Services/SettingsService.cs

@@ -4,7 +4,9 @@ using System.Text.Json;
 using System.Text.Json.Serialization;
 using System.Windows.Media;
 using System.Windows.Threading;
+using CursorLang.Interop;
 using CursorLang.Models;
+using Windows.Storage;
 
 namespace CursorLang.Services;
 
@@ -31,20 +33,36 @@ public sealed class SettingsService : IDisposable
         Converters = { new ColorJsonConverter(), new JsonStringEnumConverter() },
     };
 
+    private const string FileName = "settings.json";
+
     private readonly string _filePath;
+    private readonly string _inheritedFilePath;
     private readonly DispatcherTimer _saveTimer;
     private AppSettings? _settings;
 
-    public SettingsService()
-    {
-        string folder = Path.Combine(
-            Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
-            "CursorLang");
-        _filePath = Path.Combine(folder, "settings.json");
+    // Sliders change their values continuously, so writing to disk
+    // is postponed until there is a pause in the changes
+    private static readonly TimeSpan SaveDelay = TimeSpan.FromMilliseconds(500);
 
-        // Ползунки меняют значения непрерывно, поэтому запись на диск
-        // откладывается до паузы в изменениях
-        _saveTimer = new DispatcherTimer { Interval = TimeSpan.FromMilliseconds(500) };
+    public SettingsService()
+        : this(
+            Path.Combine(GetSettingsFolder(), FileName),
+            Path.Combine(GetSeparateInstallFolder(), FileName),
+            SaveDelay)
+    {
+    }
+
+    /// <summary>
+    /// Sets the storage locations and the save delay explicitly — thereby making it
+    /// possible to check the work with the file without touching the settings of the
+    /// user themselves.
+    /// </summary>
+    internal SettingsService(string filePath, string inheritedFilePath, TimeSpan saveDelay)
+    {
+        _filePath = filePath;
+        _inheritedFilePath = inheritedFilePath;
+
+        _saveTimer = new DispatcherTimer { Interval = saveDelay };
         _saveTimer.Tick += OnSaveTimerTick;
     }
 
@@ -54,8 +72,29 @@ public sealed class SettingsService : IDisposable
     /// </summary>
     public AppSettings Load()
     {
-        _settings = ReadFile() ?? CreateDefault();
+        AppSettings? stored = ReadFile(_filePath);
+
+        // There is no file of our own — the application may well have been configured
+        // before the move to a package. Taking the settings from there beats starting
+        // from a blank slate
+        bool inherited = stored is null && _filePath != _inheritedFilePath;
+        if (inherited)
+        {
+            stored = ReadFile(_inheritedFilePath);
+            inherited = stored is not null;
+        }
+
+        _settings = stored ?? CreateDefault();
         _settings.PropertyChanged += OnSettingsChanged;
+
+        // Moved settings are fixed in the new place right away rather than on the
+        // first edit: otherwise the application would read someone else's file every
+        // time until then
+        if (inherited)
+        {
+            Save();
+        }
+
         return _settings;
     }
 
@@ -89,16 +128,39 @@ public sealed class SettingsService : IDisposable
         }
     }
 
-    private AppSettings? ReadFile()
+    /// <summary>
+    /// The folder the application writes its settings to.
+    /// </summary>
+    private static string GetSettingsFolder()
+    {
+        if (!PackageIdentityNative.IsPackaged)
+        {
+            return GetSeparateInstallFolder();
+        }
+
+        // A package has a data folder of its own, which Windows creates and removes
+        // itself. The application name is not appended to it: the folder belongs to it alone anyway
+        return ApplicationData.Current.LocalFolder.Path;
+    }
+
+    /// <summary>
+    /// The settings folder of a separately installed application — the same source
+    /// the package inherits the settings from on the first launch.
+    /// </summary>
+    private static string GetSeparateInstallFolder() => Path.Combine(
+        Environment.GetFolderPath(Environment.SpecialFolder.ApplicationData),
+        "CursorLang");
+
+    private static AppSettings? ReadFile(string path)
     {
         try
         {
-            if (!File.Exists(_filePath))
+            if (!File.Exists(path))
             {
                 return null;
             }
 
-            return JsonSerializer.Deserialize<AppSettings>(File.ReadAllText(_filePath), SerializerOptions);
+            return JsonSerializer.Deserialize<AppSettings>(File.ReadAllText(path), SerializerOptions);
         }
         catch (Exception e) when (e is IOException or UnauthorizedAccessException or JsonException)
         {