feat: add app settings manager to do the reading and writing

src/AltGen.Console/Config/RemoveConfigCommand.cs

@@ -1,39 +1,30 @@
 namespace AltGen.Console.Config;
 
 sealed class RemoveConfigCommand(
-  IFileSystem fileSystem,
-  IAnsiConsole console
+  IAnsiConsole console,
+  IAppSettingsManager settingsManager
 ) : AsyncCommand<RemoveConfigCommand.Settings>
 {
-  readonly IFileSystem _fileSystem = fileSystem;
   readonly IAnsiConsole _console = console;
+  readonly IAppSettingsManager _settingsManager = settingsManager;
 
-  public class Settings(IFileSystem fileSystem) : CommandSettings
+  public class Settings : CommandSettings
   {
-    readonly IFileSystem _fileSystem = fileSystem;
-
     [CommandArgument(1, "<provider>")]
     [Description("The provider to remove.")]
     public string Provider { get; init; } = string.Empty;
-
-    public string SettingsPath => _fileSystem.Path.Combine(AppContext.BaseDirectory, AppSettings.SettingsFileName);
   }
 
   public override async Task<int> ExecuteAsync(CommandContext context, Settings settings)
   {
-    var exists = _fileSystem.Path.Exists(settings.SettingsPath);
-
-    if (exists is false)
+    if (_settingsManager.AppSettingsExist() is false)
     {
       throw new ConfigException("No existing settings found.");
     }
 
-    var settingsJson = await _fileSystem.File.ReadAllTextAsync(settings.SettingsPath);
-    var appSettings = JsonSerializer.Deserialize<AppSettings>(settingsJson, JsonOptions.Default)
-      ?? throw new ConfigException("Failed to deserialize app settings.");
+    var appSettings = await _settingsManager.GetAppSettingsAsync();
     var updatedAppSettings = appSettings.RemoveProvider(settings);
-    var updatedJson = JsonSerializer.Serialize(updatedAppSettings, JsonOptions.Default);
-    await _fileSystem.File.WriteAllTextAsync(settings.SettingsPath, updatedJson);
+    await _settingsManager.SaveAppSettingsAsync(updatedAppSettings);
     _console.MarkupLine($"[bold]{settings.Provider}[/] has been removed.");
     return 0;
   }