init 1.0.0

2026-06-19 00:42:00 +02:00
commit 5ca960746b
67 changed files with 3261 additions and 0 deletions
@@ -0,0 +1,64 @@
+using LiteDB;
+using LehrerApp.Sync.Models;
+
+namespace LehrerApp.Api;
+
+public class SnapshotStore(string dataPath) : IDisposable
+{
+    private readonly LiteDatabase _db =
+        new(Path.Combine(dataPath, "snapshots.db"));
+    private readonly Timer _cleanup;
+
+    public SnapshotStore(string dataPath, bool unused = false) : this(dataPath)
+    {
+        Directory.CreateDirectory(dataPath);
+        _cleanup = new(_ => Clean(), null, TimeSpan.FromHours(1), TimeSpan.FromHours(1));
+    }
+
+    private ILiteCollection<SnapshotEntry> Col => _db.GetCollection<SnapshotEntry>("snap");
+
+    public SnapshotUploadResponse Store(string userId, SnapshotUploadRequest req)
+    {
+        Col.DeleteMany(e => e.UserId == userId);
+        var code  = NewCode();
+        var entry = new SnapshotEntry { Code = code, UserId = userId,
+            EncryptedPayload = req.EncryptedPayload,
+            EncryptedSyncKey = req.EncryptedSyncKey,
+            SourceDeviceType = req.DeviceType,
+            CreatedAt = DateTime.UtcNow, ExpiresAt = DateTime.UtcNow.AddHours(24) };
+        Col.Insert(entry);
+        return new() { Code = code, ExpiresAt = entry.ExpiresAt };
+    }
+
+    public SnapshotDownloadResponse? Retrieve(string userId, string code)
+    {
+        var e = Col.FindOne(x => x.UserId == userId && x.Code == code.ToUpperInvariant());
+        if (e is null || e.ExpiresAt < DateTime.UtcNow) { if (e is not null) Col.Delete(e.Id); return null; }
+        Col.Delete(e.Id);
+        return new() { EncryptedPayload = e.EncryptedPayload, EncryptedSyncKey = e.EncryptedSyncKey,
+                       CreatedAt = e.CreatedAt, SourceDeviceType = e.SourceDeviceType };
+    }
+
+    private void Clean() => Col.DeleteMany(e => e.ExpiresAt < DateTime.UtcNow);
+
+    private static string NewCode()
+    {
+        string[] animals = ["TIGER","ADLER","DACHS","LUCHS","FALKE","IGEL","ELCH","FUCHS","RABE","WOLF","BISON","LAMM","EULE","BIBER","STORCH"];
+        string[] colors  = ["BLAU","GRUEN","ROT","GOLD","GRAU","CYAN","ROSA","LILA","SAND","MINT"];
+        return $"{animals[Random.Shared.Next(animals.Length)]}-{Random.Shared.Next(10,99)}-{colors[Random.Shared.Next(colors.Length)]}";
+    }
+
+    public void Dispose() { _cleanup?.Dispose(); _db.Dispose(); }
+}
+
+internal class SnapshotEntry
+{
+    public ObjectId Id { get; set; } = ObjectId.NewObjectId();
+    public string Code { get; set; } = "";
+    public string UserId { get; set; } = "";
+    public string EncryptedPayload { get; set; } = "";
+    public string EncryptedSyncKey { get; set; } = "";
+    public DeviceType SourceDeviceType { get; set; }
+    public DateTime CreatedAt { get; set; }
+    public DateTime ExpiresAt { get; set; }
+}