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 +1,84 @@
+using LiteDB;
+using LehrerApp.Sync.Models;
+
+namespace LehrerApp.Api;
+
+/// <summary>
+/// Append-only Event-Log pro User. Server versteht Payload nicht.
+/// </summary>
+public class EventStore(string dataPath) : IDisposable
+{
+    private readonly Dictionary<string, LiteDatabase> _dbs = new();
+    private readonly Lock _lock = new();
+
+    public PushResponse Push(string userId, List<SyncEvent> events)
+    {
+        var col     = GetCol(userId);
+        var seq     = LastSeq(col);
+        var rejects = new List<Guid>();
+        foreach (var e in events.OrderBy(e => e.Timestamp))
+        {
+            var recent = col.FindOne(x =>
+                x.EntityType == e.EntityType && x.EntityId == e.EntityId &&
+                x.DeviceId != e.DeviceId && x.Timestamp > e.Timestamp.AddSeconds(-30));
+            if (recent is not null) { rejects.Add(e.EventId); continue; }
+            col.Insert(new ServerEvent { EventId = e.EventId, DeviceId = e.DeviceId,
+                DeviceType = e.DeviceType, Timestamp = e.Timestamp,
+                ClientSeq = e.SequenceNr, ServerSeq = ++seq,
+                EntityType = e.EntityType, EntityId = e.EntityId,
+                Operation = e.Operation, Payload = e.Payload });
+        }
+        return new() { Success = true, ServerSequenceNr = seq, ConflictingEventIds = rejects };
+    }
+
+    public PullResponse Pull(string userId, long since, string requestingDeviceId)
+    {
+        var col    = GetCol(userId);
+        var events = col.Find(e => e.ServerSeq > since && e.DeviceId != requestingDeviceId)
+            .OrderBy(e => e.ServerSeq).Take(500)
+            .Select(e => new SyncEvent { EventId = e.EventId, DeviceId = e.DeviceId,
+                DeviceType = e.DeviceType, Timestamp = e.Timestamp,
+                SequenceNr = e.ServerSeq, EntityType = e.EntityType,
+                EntityId = e.EntityId, Operation = e.Operation, Payload = e.Payload })
+            .ToList();
+        return new() { Events = events, ServerSequenceNr = LastSeq(col) };
+    }
+
+    private ILiteCollection<ServerEvent> GetCol(string userId)
+    {
+        lock (_lock)
+        {
+            if (!_dbs.TryGetValue(userId, out var db))
+            {
+                var safe = string.Concat(userId.Where(c => char.IsLetterOrDigit(c) || c == '-'));
+                db = new LiteDatabase(Path.Combine(dataPath, $"{safe}.db"));
+                _dbs[userId] = db;
+            }
+            var col = db.GetCollection<ServerEvent>("events");
+            col.EnsureIndex(x => x.ServerSeq);
+            return col;
+        }
+    }
+
+    private static long LastSeq(ILiteCollection<ServerEvent> col)
+    {
+        var last = col.FindOne(Query.All(nameof(ServerEvent.ServerSeq), Query.Descending));
+        return last?.ServerSeq ?? 0;
+    }
+
+    public void Dispose() { foreach (var db in _dbs.Values) db.Dispose(); }
+}
+
+internal class ServerEvent
+{
+    public Guid EventId { get; set; }
+    public string DeviceId { get; set; } = "";
+    public DeviceType DeviceType { get; set; }
+    public DateTime Timestamp { get; set; }
+    public long ClientSeq { get; set; }
+    public long ServerSeq { get; set; }
+    public string EntityType { get; set; } = "";
+    public string EntityId { get; set; } = "";
+    public string Operation { get; set; } = "";
+    public string Payload { get; set; } = "";
+}