From ad0bca5192d72979bfa4afa0988e832d9ae3d292 Mon Sep 17 00:00:00 2001
From: Salvador Cipolla <shivanuo@hotmail.com>
Date: Sun, 22 Mar 2026 12:09:54 -0300
Subject: [PATCH] Implement download anti-stuck check

---
 Knossos.NET/Models/GlobalSettings.cs          |  3 ++
 .../ViewModels/GlobalSettingsViewModel.cs     |  9 +++++
 .../Templates/Tasks/DownloadFile.cs           | 33 +++++++++++++++++++
 Knossos.NET/Views/GlobalSettingsView.axaml    |  5 +++
 4 files changed, 50 insertions(+)

diff --git a/Knossos.NET/Models/GlobalSettings.cs b/Knossos.NET/Models/GlobalSettings.cs
index 574e3815..6bd7712d 100644
--- a/Knossos.NET/Models/GlobalSettings.cs
+++ b/Knossos.NET/Models/GlobalSettings.cs
@@ -127,6 +127,8 @@ public StandaloneServerSettings(MultiCfg multiCfg, string id, string version, in
         public int logLevel { get; set; } = 1;
         [JsonPropertyName("global_cmdline")]
         public string? globalCmdLine { get; set; } = null;
+        [JsonPropertyName("anti-stuck")]
+        public bool antiStuck { get; set; } = true;
         [JsonPropertyName("force_sse2")]
         public bool forceSSE2 { get; set; } = false;
         [JsonPropertyName("max_concurrent_subtasks")]
@@ -724,6 +726,7 @@ public void Load()
                         closeToTray = tempSettings.closeToTray;
                         ignoredLauncherUpdates = tempSettings.ignoredLauncherUpdates;
                         hiddenModIds = tempSettings.hiddenModIds;
+                        antiStuck = tempSettings.antiStuck;
                         if (hiddenModIds.Any())
                         {
                             foreach (var hiddenMod in hiddenModIds)
diff --git a/Knossos.NET/ViewModels/GlobalSettingsViewModel.cs b/Knossos.NET/ViewModels/GlobalSettingsViewModel.cs
index 59a3200f..8e9188eb 100644
--- a/Knossos.NET/ViewModels/GlobalSettingsViewModel.cs
+++ b/Knossos.NET/ViewModels/GlobalSettingsViewModel.cs
@@ -71,6 +71,13 @@ public partial class GlobalSettingsViewModel : ViewModelBase
         [ObservableProperty]
         internal string basePath = string.Empty; //When this is changed settings are saved immediately.
 
+        private bool antiStuck = true;
+        internal bool AntiStuck
+        {
+            get { return antiStuck; }
+            set { if (antiStuck != value) { this.SetProperty(ref antiStuck, value); UnCommitedChanges = true; } }
+        }
+
         private bool blCfNebula = false;
         internal bool BlCfNebula
         {
@@ -669,6 +676,7 @@ public void LoadData()
             EnvVars = Knossos.globalSettings.envVars;
             ShowDevOptions = Knossos.globalSettings.showDevOptions || NoSystemCMD;
             CloseToTray = Knossos.globalSettings.closeToTray;
+            AntiStuck = Knossos.globalSettings.antiStuck;
 
             /* VIDEO SETTINGS */
             //RESOLUTION
@@ -1249,6 +1257,7 @@ internal void SaveCommand()
             Knossos.globalSettings.envVars = EnvVars;
             Knossos.globalSettings.showDevOptions = ShowDevOptions;
             Knossos.globalSettings.closeToTray = CloseToTray;
+            Knossos.globalSettings.antiStuck = AntiStuck;
 
             /* VIDEO */
             //Resolution
diff --git a/Knossos.NET/ViewModels/Templates/Tasks/DownloadFile.cs b/Knossos.NET/ViewModels/Templates/Tasks/DownloadFile.cs
index 8570ec91..5e7b341b 100644
--- a/Knossos.NET/ViewModels/Templates/Tasks/DownloadFile.cs
+++ b/Knossos.NET/ViewModels/Templates/Tasks/DownloadFile.cs
@@ -171,6 +171,15 @@ private async Task<bool> Download(Uri downloadUrl, string destinationFilePath, F
                 Log.Add(Log.LogSeverity.Information, "TaskItemViewModel.Download()", "Downloading file: " + downloadUrl);
                 System.Diagnostics.Stopwatch stopwatch = new System.Diagnostics.Stopwatch();
 
+                // ANTI-STUCK CONFIG
+                // If less ANTI_STUCK_MIN_BYTES are downloaded in ANTI_STUCK_CHECK_SECONDS
+                // The download is restarted with a mirror swap
+                const int ANTI_STUCK_CHECK_SECONDS = 30;
+                const long ANTI_STUCK_MIN_BYTES = 102400; // 100 KB (3.33 KB/s)
+                DateTime lastStallCheck = DateTime.UtcNow;
+                long bytesAtLastCheck = 0;
+                // =================================
+
                 var httpClient = KnUtils.GetHttpClient();
                 if (downloadUrl.ToString().ToLower().Contains(".json"))
                 {
@@ -219,6 +228,9 @@ private async Task<bool> Download(Uri downloadUrl, string destinationFilePath, F
                         {
                             throw new TaskCanceledException();
                         }
+                        // Reset anti-stuck counter on paused downloads
+                        lastStallCheck = DateTime.UtcNow;
+                        bytesAtLastCheck = totalBytesRead;
                     }
 
                     if (cancellationTokenSource!.IsCancellationRequested)
@@ -253,6 +265,27 @@ private async Task<bool> Download(Uri downloadUrl, string destinationFilePath, F
                         stopwatch.Restart();
                     }
 
+                    // Anti-Stuck check
+                    if (Knossos.globalSettings.antiStuck && (DateTime.UtcNow - lastStallCheck).TotalSeconds >= ANTI_STUCK_CHECK_SECONDS)
+                    {
+                        long bytesInWindow = totalBytesRead - bytesAtLastCheck;
+
+                        if (bytesInWindow < ANTI_STUCK_MIN_BYTES)
+                        {
+                            string speedStr = KnUtils.FormatBytes(bytesInWindow / ANTI_STUCK_CHECK_SECONDS) + "/s";
+                            Log.Add(Log.LogSeverity.Warning, "TaskItemViewModel.Download",
+                                $"[ANTI-STUCK] Mirror {CurrentMirror ?? downloadUrl.Host} is stuck (too slow). " +
+                                $"Only {KnUtils.FormatBytes(bytesInWindow)} in {ANTI_STUCK_CHECK_SECONDS}s ({speedStr}). " +
+                                "Changing to a diferent mirror...");
+
+                            return false;
+                        }
+
+                        // reset counter
+                        lastStallCheck = DateTime.UtcNow;
+                        bytesAtLastCheck = totalBytesRead;
+                    }
+                    // =================================
 
                     if (readCount % 100 == 0)
                     {
diff --git a/Knossos.NET/Views/GlobalSettingsView.axaml b/Knossos.NET/Views/GlobalSettingsView.axaml
index 6359e469..55fa3fa8 100644
--- a/Knossos.NET/Views/GlobalSettingsView.axaml
+++ b/Knossos.NET/Views/GlobalSettingsView.axaml
@@ -128,6 +128,11 @@
 								<CheckBox Margin="25,0,0,0" IsChecked="{Binding !BlHestia}">hestia.feralhosting.com</CheckBox>
 							</WrapPanel>
 						</Grid>
+						<!-- Anti Stuck -->
+						<WrapPanel Margin="5,10,0,0" ToolTip.Tip="During file downloads, if less than 100KB are downloaded every 30 seconds, the download will be restarted on a different mirror.">
+							<Label Margin="0,5,0,0" Width="210">Download anti-stuck</Label>
+							<ToggleSwitch Margin="1,0,0,0" IsChecked="{Binding AntiStuck}"></ToggleSwitch>
+						</WrapPanel>
 						<!-- Log File -->
 						<WrapPanel Margin="5,10,0,0">
 							<Label Margin="0,5,0,0" Width="210">Enable Logging</Label>