⚡ Optimized last active flush handler

DysonNetwork.Pass/Handlers/LastActiveFlushHandler.cs

@@ -12,11 +12,14 @@ public class LastActiveInfo
     public Instant SeenAt { get; set; }
 }
 
-public class LastActiveFlushHandler(IServiceProvider serviceProvider) : IFlushHandler<LastActiveInfo>
+public class LastActiveFlushHandler(IServiceProvider srp, ILogger<LastActiveFlushHandler> logger)
+    : IFlushHandler<LastActiveInfo>
 {
     public async Task FlushAsync(IReadOnlyList<LastActiveInfo> items)
     {
-        using var scope = serviceProvider.CreateScope();
+        logger.LogInformation("Flushing {Count} LastActiveInfo items...", items.Count);
+        
+        using var scope = srp.CreateScope();
         var db = scope.ServiceProvider.GetRequiredService<AppDatabase>();
 
         // Remove duplicates by grouping on (sessionId, accountId), taking the most recent SeenAt
@@ -26,29 +29,27 @@ public class LastActiveFlushHandler(IServiceProvider serviceProvider) : IFlushHa
             .ToList();
 
         // Build dictionaries so we can match session/account IDs to their new "last seen" timestamps
-        var sessionIdMap = distinctItems
+        var sessionMap = distinctItems
             .GroupBy(x => x.Session.Id)
             .ToDictionary(g => g.Key, g => g.Last().SeenAt);
 
-        var accountIdMap = distinctItems
+        var accountMap = distinctItems
             .GroupBy(x => x.Account.Id)
             .ToDictionary(g => g.Key, g => g.Last().SeenAt);
 
-        // Update sessions using native EF Core ExecuteUpdateAsync
-        foreach (var kvp in sessionIdMap)
-        {
-            await db.AuthSessions
-                .Where(s => s.Id == kvp.Key)
-                .ExecuteUpdateAsync(s => s.SetProperty(x => x.LastGrantedAt, kvp.Value));
-        }
-
-        // Update account profiles using native EF Core ExecuteUpdateAsync
-        foreach (var kvp in accountIdMap)
-        {
-            await db.AccountProfiles
-                .Where(a => a.AccountId == kvp.Key)
-                .ExecuteUpdateAsync(a => a.SetProperty(x => x.LastSeenAt, kvp.Value));
-        }
+        var now = SystemClock.Instance.GetCurrentInstant();
+        
+        var updatingSessions = sessionMap.Select(x => x.Key).ToList();
+        var sessionUpdates = await db.AuthSessions
+            .Where(s => updatingSessions.Contains(s.Id))
+            .ExecuteUpdateAsync(s => s.SetProperty(x => x.LastGrantedAt, now));
+        logger.LogInformation("Updated {Count} auth sessions according to LastActiveInfo", sessionUpdates);
+        
+        var updatingAccounts = accountMap.Select(x => x.Key).ToList();
+        var profileUpdates = await db.AccountProfiles
+            .Where(a => updatingAccounts.Contains(a.AccountId))
+            .ExecuteUpdateAsync(a => a.SetProperty(x => x.LastSeenAt, now));
+        logger.LogInformation("Updated {Count} account profiles according to LastActiveInfo", profileUpdates);
     }
 }