1 files changed, 27 insertions, 7 deletions

diff --git a/LibMatrix/Helpers/SyncHelper.cs b/LibMatrix/Helpers/SyncHelper.cs
index 1833bd0..07c3bb0 100644
--- a/LibMatrix/Helpers/SyncHelper.cs
+++ b/LibMatrix/Helpers/SyncHelper.cs
@@ -3,12 +3,13 @@ using System.Net.Http.Json;
 using ArcaneLibs.Extensions;
 using LibMatrix.Filters;
 using LibMatrix.Homeservers;
+using LibMatrix.Interfaces.Services;
 using LibMatrix.Responses;
 using Microsoft.Extensions.Logging;
 
 namespace LibMatrix.Helpers;
 
-public class SyncHelper(AuthenticatedHomeserverGeneric homeserver, ILogger? logger = null) {
+public class SyncHelper(AuthenticatedHomeserverGeneric homeserver, ILogger? logger = null, IStorageProvider? storageProvider = null) {
     private SyncFilter? _filter;
     private string? _namedFilterName;
     private bool _filterIsDirty = false;
@@ -51,7 +52,7 @@ public class SyncHelper(AuthenticatedHomeserverGeneric homeserver, ILogger? logg
 
     public TimeSpan MinimumDelay { get; set; } = new(0);
 
-    private async Task updateFilterAsync() {
+    private async Task UpdateFilterAsync() {
         if (!string.IsNullOrWhiteSpace(NamedFilterName)) {
             _filterId = await homeserver.NamedCaches.FilterCache.GetOrSetValueAsync(NamedFilterName);
             if (_filterId is null)
@@ -74,8 +75,27 @@ public class SyncHelper(AuthenticatedHomeserverGeneric homeserver, ILogger? logg
             throw new ArgumentNullException(nameof(homeserver.ClientHttpClient), "Null passed as homeserver for SyncHelper!");
         }
 
+        if (storageProvider is null) return await SyncAsyncInternal(cancellationToken);
+
+        var key = Since ?? "init";
+        if (await storageProvider.ObjectExistsAsync(key)) {
+            var cached = await storageProvider.LoadObjectAsync<SyncResponse>(key);
+            // We explicitly check that NextBatch doesn't match since to prevent infinite loops...
+            if (cached is not null && cached.NextBatch != Since) {
+                logger?.LogInformation("SyncHelper: Using cached sync response for {}", key);
+                return cached;
+            }
+        }
+
+        var sync = await SyncAsyncInternal(cancellationToken);
+        // Ditto here.
+        if (sync is not null && sync.NextBatch != Since) await storageProvider.SaveObjectAsync(key, sync);
+        return sync;
+    }
+
+    private async Task<SyncResponse?> SyncAsyncInternal(CancellationToken? cancellationToken = null) {
         var sw = Stopwatch.StartNew();
-        if (_filterIsDirty) await updateFilterAsync();
+        if (_filterIsDirty) await UpdateFilterAsync();
 
         var url = $"/_matrix/client/v3/sync?timeout={Timeout}&set_presence={SetPresence}&full_state={(FullState ? "true" : "false")}";
         if (!string.IsNullOrWhiteSpace(Since)) url += $"&since={Since}";
@@ -86,11 +106,11 @@ public class SyncHelper(AuthenticatedHomeserverGeneric homeserver, ILogger? logg
         try {
             var httpResp = await homeserver.ClientHttpClient.GetAsync(url, cancellationToken ?? CancellationToken.None);
             if (httpResp is null) throw new NullReferenceException("Failed to send HTTP request");
-            logger?.LogInformation("Got sync response: {} bytes, {} elapsed", httpResp.Content.Headers.ContentLength ?? -1, sw.Elapsed);
+            logger?.LogInformation("Got sync response: {} bytes, {} elapsed", httpResp.GetContentLength(), sw.Elapsed);
             var deserializeSw = Stopwatch.StartNew();
-            var resp = await httpResp.Content.ReadFromJsonAsync<SyncResponse>(cancellationToken: cancellationToken ?? CancellationToken.None,
+            var resp = await httpResp.Content.ReadFromJsonAsync(cancellationToken: cancellationToken ?? CancellationToken.None,
                 jsonTypeInfo: SyncResponseSerializerContext.Default.SyncResponse);
-            logger?.LogInformation("Deserialized sync response: {} bytes, {} elapsed, {} total", httpResp.Content.Headers.ContentLength ?? -1, deserializeSw.Elapsed, sw.Elapsed);
+            logger?.LogInformation("Deserialized sync response: {} bytes, {} elapsed, {} total", httpResp.GetContentLength(), deserializeSw.Elapsed, sw.Elapsed);
             var timeToWait = MinimumDelay.Subtract(sw.Elapsed);
             if (timeToWait.TotalMilliseconds > 0)
                 await Task.Delay(timeToWait);
@@ -210,7 +230,7 @@ public class SyncHelper(AuthenticatedHomeserverGeneric homeserver, ILogger? logg
     /// Event fired when an account data event is received
     /// </summary>
     public List<Func<StateEventResponse, Task>> AccountDataReceivedHandlers { get; } = new();
-    
+
     private void Log(string message) {
         if (logger is null) Console.WriteLine(message);
         else logger.LogInformation(message);