Initial

2026-03-29 23:47:31 +02:00
commit 216d5d2280
75 changed files with 5702 additions and 0 deletions
--- a/LehrerApp.Sync/SyncEngine.cs
+++ b/LehrerApp.Sync/SyncEngine.cs
@@ -0,0 +1,186 @@
+using System.Net.Http.Json;
+using LehrerApp.Sync.Models;
+
+namespace LehrerApp.Sync;
+
+/// <summary>
+/// Orchestriert Push, Pull, EventApply und Snapshot-Export.
+/// Automatisch alle N Minuten + manuell auslösbar.
+/// </summary>
+public class SyncEngine : IDisposable
+{
+    private readonly EventQueue _queue;
+    private readonly ConflictResolver _resolver;
+    private readonly EventApplier? _applier;
+    private readonly ReadableSnapshotService? _snapshotExport;
+    private readonly HttpClient _http;
+    private readonly SyncConfig _config;
+    private readonly Timer _timer;
+
+    public SyncStatus Status { get; private set; } = new();
+    public event Action<SyncStatus>? StatusChanged;
+
+    public SyncEngine(
+        EventQueue queue,
+        ConflictResolver resolver,
+        HttpClient http,
+        SyncConfig config,
+        EventApplier? applier = null,
+        ReadableSnapshotService? snapshotExport = null)
+    {
+        _queue          = queue;
+        _resolver       = resolver;
+        _http           = http;
+        _config         = config;
+        _applier        = applier;
+        _snapshotExport = snapshotExport;
+
+        _timer = new Timer(
+            async _ => await SyncNowAsync(isAutomatic: true),
+            null,
+            TimeSpan.FromMinutes(config.AutoSyncIntervalMinutes),
+            TimeSpan.FromMinutes(config.AutoSyncIntervalMinutes));
+
+        UpdateStatus();
+    }
+
+    // ── Öffentliche API ───────────────────────────────────────────────────────
+
+    public async Task<SyncResult> SyncNowAsync(bool isAutomatic = false)
+    {
+        if (Status.State == SyncState.Syncing)
+            return new SyncResult { Skipped = true, Reason = "Sync bereits aktiv" };
+
+        SetState(SyncState.Syncing);
+
+        try
+        {
+            // 1. Ausstehende Events pushen
+            var pushResult = await PushAsync();
+
+            // 2. Neue Events vom Server holen
+            var pullResult = await PullAsync();
+
+            // 3. Geholte Events auf LiteDB anwenden
+            if (_applier is not null && pullResult.Events.Count > 0)
+                _applier.ApplyAll(pullResult.Events);
+
+            // 4. Nach erfolgreichem Sync: lesbaren Snapshot exportieren
+            //    (nur bei automatischem Sync oder explizit – nicht bei jedem
+            //     manuellen Push um Traffic zu sparen)
+            if (_snapshotExport is not null && (isAutomatic || pushResult.Pushed > 0))
+                await _snapshotExport.ExportAndPushAsync();
+
+            _queue.SetLastSyncAt(DateTime.UtcNow);
+            SetState(SyncState.Idle);
+
+            return new SyncResult
+            {
+                Success       = true,
+                EventsPushed  = pushResult.Pushed,
+                EventsPulled  = pullResult.Events.Count,
+                Conflicts     = pullResult.Conflicts,
+            };
+        }
+        catch (HttpRequestException)
+        {
+            SetState(SyncState.Offline);
+            return new SyncResult { Success = false, Reason = "Server nicht erreichbar" };
+        }
+        catch (Exception ex)
+        {
+            SetState(SyncState.Error, ex.Message);
+            return new SyncResult { Success = false, Reason = ex.Message };
+        }
+    }
+
+    // ── Push ──────────────────────────────────────────────────────────────────
+
+    private async Task<(int Pushed, int Conflicts)> PushAsync()
+    {
+        var pending = _queue.GetPending(maxBatch: 200);
+        if (pending.Count == 0) return (0, 0);
+
+        var response = await _http.PostAsJsonAsync("/api/sync/push", pending);
+        response.EnsureSuccessStatusCode();
+
+        var result = await response.Content.ReadFromJsonAsync<PushResponse>();
+        if (result is null) return (0, 0);
+
+        var sentIds = pending
+            .Where(e => !result.ConflictingEventIds.Contains(e.EventId))
+            .Select(e => e.EventId);
+        _queue.Acknowledge(sentIds);
+        _queue.SetLastServerSequenceNr(result.ServerSequenceNr);
+
+        return (pending.Count - result.ConflictingEventIds.Count,
+                result.ConflictingEventIds.Count);
+    }
+
+    // ── Pull ──────────────────────────────────────────────────────────────────
+
+    private async Task<(List<SyncEvent> Events, int Conflicts)> PullAsync()
+    {
+        var since = _queue.GetLastServerSequenceNr();
+        var response = await _http.GetFromJsonAsync<PullResponse>(
+            $"/api/sync/pull?since={since}&deviceId={_config.DeviceId}");
+
+        if (response is null || response.Events.Count == 0)
+            return ([], 0);
+
+        var conflicts = 0;
+        foreach (var remoteEvent in response.Events)
+        {
+            var conflict = _resolver.TryResolve(remoteEvent, _config.DeviceId);
+            if (conflict is not null)
+            {
+                _queue.AddConflict(conflict);
+                conflicts++;
+            }
+        }
+
+        _queue.SetLastServerSequenceNr(response.ServerSequenceNr);
+        return (response.Events, conflicts);
+    }
+
+    // ── Hilfsmethoden ─────────────────────────────────────────────────────────
+
+    private void SetState(SyncState state, string? error = null)
+    {
+        Status = new SyncStatus
+        {
+            State         = state,
+            LastSyncAt    = _queue.GetLastSyncAt(),
+            PendingEvents = _queue.PendingCount(),
+            ConflictCount = _queue.ConflictCount(),
+            ErrorMessage  = error,
+        };
+        StatusChanged?.Invoke(Status);
+    }
+
+    private void UpdateStatus() => SetState(Status.State);
+
+    public void Dispose()
+    {
+        _timer.Dispose();
+        _queue.Dispose();
+    }
+}
+
+public class SyncConfig
+{
+    public string ServerUrl { get; set; } = "";
+    public string DeviceId { get; set; } = "";
+    public DeviceType DeviceType { get; set; } = DeviceType.Desktop;
+    public int AutoSyncIntervalMinutes { get; set; } = 5;
+}
+
+public class SyncResult
+{
+    public bool Success { get; set; }
+    public bool Skipped { get; set; }
+    public string? Reason { get; set; }
+    public int EventsPushed { get; set; }
+    public int EventsPulled { get; set; }
+    public int Conflicts { get; set; }
+}