1 files changed, 174 insertions, 0 deletions
diff --git a/LibMatrix/Helpers/SyncStateResolver.cs b/LibMatrix/Helpers/SyncStateResolver.cs
new file mode 100644
index 0000000..0070d60
--- /dev/null
+++ b/LibMatrix/Helpers/SyncStateResolver.cs
@@ -0,0 +1,174 @@
+using LibMatrix.Extensions;
+using LibMatrix.Filters;
+using LibMatrix.Homeservers;
+using LibMatrix.Responses;
+using Microsoft.Extensions.Logging;
+
+namespace LibMatrix.Helpers;
+
+public class SyncStateResolver(AuthenticatedHomeserverGeneric homeserver, ILogger? logger = null) {
+    public string? Since { get; set; }
+    public int Timeout { get; set; } = 30000;
+    public string? SetPresence { get; set; } = "online";
+    public SyncFilter? Filter { get; set; }
+    public bool FullState { get; set; } = false;
+
+    public SyncResponse? MergedState { get; set; } = null!;
+
+    private SyncHelper _syncHelper = new SyncHelper(homeserver, logger);
+
+    public async Task<(SyncResponse next, SyncResponse merged)> ContinueAsync(CancellationToken? cancellationToken = null) {
+        // copy properties
+        _syncHelper.Since = Since;
+        _syncHelper.Timeout = Timeout;
+        _syncHelper.SetPresence = SetPresence;
+        _syncHelper.Filter = Filter;
+        _syncHelper.FullState = FullState;
+        // run sync
+        var sync = await _syncHelper.SyncAsync(cancellationToken);
+        if (sync is null) return await ContinueAsync(cancellationToken);
+        if (MergedState is null) MergedState = sync;
+        else MergedState = MergeSyncs(MergedState, sync);
+        Since = sync.NextBatch;
+        return (sync, MergedState);
+    }
+
+    private SyncResponse MergeSyncs(SyncResponse oldState, SyncResponse newState) {
+        oldState.NextBatch = newState.NextBatch ?? oldState.NextBatch;
+
+        oldState.AccountData ??= new();
+        oldState.AccountData.Events ??= new();
+        if (newState.AccountData?.Events is not null)
+            oldState.AccountData.Events.MergeStateEventLists(newState.AccountData?.Events ?? new());
+
+        oldState.Presence ??= new();
+        if (newState.Presence?.Events is not null)
+            oldState.Presence.Events.MergeStateEventLists(newState.Presence?.Events ?? new());
+
+        oldState.DeviceOneTimeKeysCount ??= new();
+        if (newState.DeviceOneTimeKeysCount is not null)
+            foreach (var (key, value) in newState.DeviceOneTimeKeysCount) {
+                oldState.DeviceOneTimeKeysCount[key] = value;
+            }
+
+        oldState.Rooms ??= new();
+        if (newState.Rooms is not null)
+            oldState.Rooms = MergeRoomsDataStructure(oldState.Rooms, newState.Rooms);
+
+        oldState.ToDevice ??= new();
+        oldState.ToDevice.Events ??= new();
+        if (newState.ToDevice?.Events is not null)
+            oldState.ToDevice.Events.MergeStateEventLists(newState.ToDevice?.Events ?? new());
+
+        oldState.DeviceLists ??= new();
+        if (newState.DeviceLists?.Changed is not null)
+            foreach (var s in oldState.DeviceLists.Changed!) {
+                oldState.DeviceLists.Changed.Add(s);
+            }
+        if (newState.DeviceLists?.Left is not null)
+            foreach (var s in oldState.DeviceLists.Left!) {
+                oldState.DeviceLists.Left.Add(s);
+            }
+
+
+        return oldState;
+    }
+
+#region Merge rooms
+
+    private SyncResponse.RoomsDataStructure MergeRoomsDataStructure(SyncResponse.RoomsDataStructure oldState, SyncResponse.RoomsDataStructure newState) {
+        oldState.Join ??= new();
+        foreach (var (key, value) in newState.Join ?? new()) {
+            if (!oldState.Join.ContainsKey(key)) oldState.Join[key] = value;
+            else oldState.Join[key] = MergeJoinedRoomDataStructure(oldState.Join[key], value);
+        }
+
+        oldState.Invite ??= new();
+        foreach (var (key, value) in newState.Invite ?? new()) {
+            if (!oldState.Invite.ContainsKey(key)) oldState.Invite[key] = value;
+            else oldState.Invite[key] = MergeInvitedRoomDataStructure(oldState.Invite[key], value);
+        }
+
+        oldState.Leave ??= new();
+        foreach (var (key, value) in newState.Leave ?? new()) {
+            if (!oldState.Leave.ContainsKey(key)) oldState.Leave[key] = value;
+            else oldState.Leave[key] = MergeLeftRoomDataStructure(oldState.Leave[key], value);
+            if (oldState.Invite.ContainsKey(key)) oldState.Invite.Remove(key);
+            if (oldState.Join.ContainsKey(key)) oldState.Join.Remove(key);
+        }
+
+        return oldState;
+    }
+
+    private SyncResponse.RoomsDataStructure.LeftRoomDataStructure MergeLeftRoomDataStructure(SyncResponse.RoomsDataStructure.LeftRoomDataStructure oldData,
+        SyncResponse.RoomsDataStructure.LeftRoomDataStructure newData) {
+        oldData.AccountData ??= new();
+        oldData.AccountData.Events ??= new();
+        oldData.Timeline ??= new();
+        oldData.Timeline.Events ??= new();
+        oldData.State ??= new();
+        oldData.State.Events ??= new();
+
+        if (newData.AccountData?.Events is not null)
+            oldData.AccountData.Events.MergeStateEventLists(newData.AccountData?.Events ?? new());
+
+        if (newData.Timeline?.Events is not null)
+            oldData.Timeline.Events.MergeStateEventLists(newData.Timeline?.Events ?? new());
+        oldData.Timeline.Limited = newData.Timeline?.Limited ?? oldData.Timeline.Limited;
+        oldData.Timeline.PrevBatch = newData.Timeline?.PrevBatch ?? oldData.Timeline.PrevBatch;
+
+        if (newData.State?.Events is not null)
+            oldData.State.Events.MergeStateEventLists(newData.State?.Events ?? new());
+
+        return oldData;
+    }
+
+    private SyncResponse.RoomsDataStructure.InvitedRoomDataStructure MergeInvitedRoomDataStructure(SyncResponse.RoomsDataStructure.InvitedRoomDataStructure oldData,
+        SyncResponse.RoomsDataStructure.InvitedRoomDataStructure newData) {
+        oldData.InviteState ??= new();
+        oldData.InviteState.Events ??= new();
+        if (newData.InviteState?.Events is not null)
+            oldData.InviteState.Events.MergeStateEventLists(newData.InviteState?.Events ?? new());
+
+        return oldData;
+    }
+
+    private SyncResponse.RoomsDataStructure.JoinedRoomDataStructure MergeJoinedRoomDataStructure(SyncResponse.RoomsDataStructure.JoinedRoomDataStructure oldData,
+        SyncResponse.RoomsDataStructure.JoinedRoomDataStructure newData) {
+        oldData.AccountData ??= new();
+        oldData.AccountData.Events ??= new();
+        oldData.Timeline ??= new();
+        oldData.Timeline.Events ??= new();
+        oldData.State ??= new();
+        oldData.State.Events ??= new();
+        oldData.Ephemeral ??= new();
+        oldData.Ephemeral.Events ??= new();
+
+        if (newData.AccountData?.Events is not null)
+            oldData.AccountData.Events.MergeStateEventLists(newData.AccountData?.Events ?? new());
+
+        if (newData.Timeline?.Events is not null)
+            oldData.Timeline.Events.MergeStateEventLists(newData.Timeline?.Events ?? new());
+        oldData.Timeline.Limited = newData.Timeline?.Limited ?? oldData.Timeline.Limited;
+        oldData.Timeline.PrevBatch = newData.Timeline?.PrevBatch ?? oldData.Timeline.PrevBatch;
+
+        if (newData.State?.Events is not null)
+            oldData.State.Events.MergeStateEventLists(newData.State?.Events ?? new());
+
+        if (newData.Ephemeral?.Events is not null)
+            oldData.Ephemeral.Events.MergeStateEventLists(newData.Ephemeral?.Events ?? new());
+
+        oldData.UnreadNotifications ??= new();
+        oldData.UnreadNotifications.HighlightCount = newData.UnreadNotifications?.HighlightCount ?? oldData.UnreadNotifications.HighlightCount;
+        oldData.UnreadNotifications.NotificationCount = newData.UnreadNotifications?.NotificationCount ?? oldData.UnreadNotifications.NotificationCount;
+
+        oldData.Summary ??= new();
+        oldData.Summary.Heroes = newData.Summary?.Heroes ?? oldData.Summary.Heroes;
+        oldData.Summary.JoinedMemberCount = newData.Summary?.JoinedMemberCount ?? oldData.Summary.JoinedMemberCount;
+        oldData.Summary.InvitedMemberCount = newData.Summary?.InvitedMemberCount ?? oldData.Summary.InvitedMemberCount;
+
+        return oldData;
+    }
+
+#endregion
+}