init 1.0.0

LehrerApp.Api/ReadableSnapshotStore.cs

@@ -0,0 +1,23 @@
+using System.Text.Json;
+using LehrerApp.Core.Models;
+
+namespace LehrerApp.Api;
+
+public class ReadableSnapshotStore(string dataPath)
+{
+    private readonly string _path = Path.Combine(dataPath, "readable");
+    private static readonly JsonSerializerOptions _opts = new() { WriteIndented = false, PropertyNamingPolicy = JsonNamingPolicy.CamelCase };
+
+    public void Store(string userId, ReadableSnapshot snap)
+    {
+        Directory.CreateDirectory(_path);
+        File.WriteAllText(FilePath(userId), JsonSerializer.Serialize(snap, _opts));
+    }
+    public ReadableSnapshot? Load(string userId)
+    {
+        var p = FilePath(userId);
+        return File.Exists(p) ? JsonSerializer.Deserialize<ReadableSnapshot>(File.ReadAllText(p), _opts) : null;
+    }
+    private string FilePath(string userId) =>
+        Path.Combine(_path, $"{string.Concat(userId.Where(c => char.IsLetterOrDigit(c) || c == '-'))}.json");
+}