first commit

Config/ConfigService.cs

@@ -0,0 +1,40 @@
+using System.Text.Json;
+
+namespace HanaToolbox.Config;
+
+public sealed class ConfigService
+{
+    private const string ConfigDir = "/etc/hanatoolbox";
+    private const string ConfigFile = "/etc/hanatoolbox/hanatoolbox.json";
+
+    public static AppConfig Load()
+    {
+        if (!File.Exists(ConfigFile))
+            return new AppConfig();
+
+        try
+        {
+            var json = File.ReadAllText(ConfigFile);
+            return JsonSerializer.Deserialize(json, AppConfigJsonContext.Default.AppConfig)
+                   ?? new AppConfig();
+        }
+        catch (Exception ex)
+        {
+            throw new InvalidOperationException(
+                $"Failed to load config from {ConfigFile}: {ex.Message}", ex);
+        }
+    }
+
+    public static void Save(AppConfig config)
+    {
+        Directory.CreateDirectory(ConfigDir);
+        Directory.CreateDirectory(StateDirectory);
+
+        var json = JsonSerializer.Serialize(config, AppConfigJsonContext.Default.AppConfig);
+        File.WriteAllText(ConfigFile, json);
+    }
+
+    public static bool Exists() => File.Exists(ConfigFile);
+
+    public static string StateDirectory => "/etc/hanatoolbox/state";
+}