From f6afe59eafb49866930c0479cab031af2efe897f Mon Sep 17 00:00:00 2001
From: Paul Hebble <pjhebble@gmail.com>
Date: Tue, 14 May 2019 19:33:51 +0000
Subject: [PATCH] Update GUI modlist if scan detects changes

---
 Core/KSP.cs                      | 35 ++++++++++++++------------
 Core/Registry/RegistryManager.cs | 42 +++++++++++++++++++++++++++++---
 GUI/MainRepo.cs                  |  9 +++++--
 3 files changed, 66 insertions(+), 20 deletions(-)

diff --git a/Core/KSP.cs b/Core/KSP.cs
index b10eedb2ea..14e3797096 100644
--- a/Core/KSP.cs
+++ b/Core/KSP.cs
@@ -404,13 +404,17 @@ public KspVersionCriteria VersionCriteria()
         /// Clears the registry of DLL data, and refreshes it by scanning GameData.
         /// This operates as a transaction.
         /// This *saves* the registry upon completion.
+        /// TODO: This would likely be better in the Registry class itself.
         /// </summary>
-        // TODO: This would likely be better in the Registry class itself.
-        public void ScanGameData()
+        /// <returns>
+        /// True if found anything different, false if same as before
+        /// </returns>
+        public bool ScanGameData()
         {
             var manager = RegistryManager.Instance(this);
             using (TransactionScope tx = CkanTransaction.CreateTransactionScope())
             {
+                var oldDlls = new HashSet<string>(manager.registry.InstalledDlls);
                 manager.registry.ClearDlls();
 
                 // TODO: It would be great to optimise this to skip .git directories and the like.
@@ -421,27 +425,28 @@ public void ScanGameData()
                 // GameData *twice*.
                 //
                 // The least evil is to walk it once, and filter it ourselves.
-                IEnumerable<string> files = Directory.EnumerateFiles(
-                                        GameData(),
-                                        "*",
-                                        SearchOption.AllDirectories
-                                    );
+                IEnumerable<string> files = Directory
+                    .EnumerateFiles(GameData(), "*", SearchOption.AllDirectories)
+                    .Where(file => dllRegex.IsMatch(file))
+                    .Select(KSPPathUtils.NormalizePath)
+                    .Where(absPath => !DllIgnoreList.Contains(ToRelativeGameDir(absPath)));
 
-                files = files.Where(file => Regex.IsMatch(file, @"\.dll$", RegexOptions.IgnoreCase));
-
-                foreach (string dll in files.Select(KSPPathUtils.NormalizePath))
+                foreach (string dll in files)
                 {
-                    var relativePath = ToRelativeGameDir(dll);
-
-                    if (!DllIgnoreList.Contains(relativePath))
-                        manager.registry.RegisterDll(this, dll);
+                    manager.registry.RegisterDll(this, dll);
                 }
+                var newDlls = new HashSet<string>(manager.registry.InstalledDlls);
+                bool dllChanged = !oldDlls.SetEquals(newDlls);                
 
-                manager.ScanDlc();
+                bool dlcChanged = manager.ScanDlc();
                 manager.Save(false);
                 tx.Complete();
+
+                return dllChanged || dlcChanged;
             }
         }
+        
+        private static readonly Regex dllRegex = new Regex(@"\.dll$", RegexOptions.IgnoreCase | RegexOptions.Compiled);
 
         #endregion
 
diff --git a/Core/Registry/RegistryManager.cs b/Core/Registry/RegistryManager.cs
index 32ddf6bbec..88ed7c26e5 100644
--- a/Core/Registry/RegistryManager.cs
+++ b/Core/Registry/RegistryManager.cs
@@ -469,22 +469,58 @@ public void ExportInstalled(string path, bool recommends, bool with_versions)
             file_transaction.WriteAllText(path, serialized);
         }
 
-        public void ScanDlc()
+        /// <summary>
+        /// Look for DLC installed in GameData
+        /// </summary>
+        /// <returns>
+        /// True if not the same list as last scan, false otherwise
+        /// </returns>
+        public bool ScanDlc()
         {
-            var testDlc = TestDlcScan();
-            var wellKnownDlc = WellKnownDlcScan();
+            var dlc = new Dictionary<string, UnmanagedModuleVersion>(registry.InstalledDlc);
+            UnmanagedModuleVersion foundVer;
+            bool changed = false;
 
             registry.ClearDlc();
 
+            var testDlc = TestDlcScan();
             foreach (var i in testDlc)
             {
+                if (!changed
+                    && (!dlc.TryGetValue(i.Key, out foundVer)
+                        || foundVer != i.Value))
+                {
+                    changed = true;
+                }
                 registry.RegisterDlc(i.Key, i.Value);
             }
 
+            var wellKnownDlc = WellKnownDlcScan();
             foreach (var i in wellKnownDlc)
             {
+                if (!changed
+                    && (!dlc.TryGetValue(i.Key, out foundVer)
+                        || foundVer != i.Value))
+                {
+                    changed = true;
+                }
                 registry.RegisterDlc(i.Key, i.Value);
             }
+            
+            // Check if anything got removed
+            if (!changed)
+            {
+                foreach (var i in dlc)
+                {
+                    if (!registry.InstalledDlc.TryGetValue(i.Key, out foundVer)
+                        || foundVer != i.Value)
+                    {
+                        changed = true;
+                        break;
+                    }
+                }
+            }
+            return changed;
         }
 
         private Dictionary<string, UnmanagedModuleVersion> TestDlcScan()
diff --git a/GUI/MainRepo.cs b/GUI/MainRepo.cs
index 2fc34454d7..36664750e8 100644
--- a/GUI/MainRepo.cs
+++ b/GUI/MainRepo.cs
@@ -30,8 +30,6 @@ public void UpdateRepo()
         {
             tabController.RenameTab("WaitTabPage", "Updating repositories");
 
-            CurrentInstance.ScanGameData();
-
             try
             {
                 m_UpdateRepoWorker.RunWorkerAsync();
@@ -65,6 +63,9 @@ private void UpdateRepo(object sender, DoWorkEventArgs e)
         {
             try
             {
+                AddStatusMessage("Scanning GameData for DLCs and manually installed modules...");
+                bool scanChanged = CurrentInstance.ScanGameData();
+    
                 AddStatusMessage("Updating repositories...");
 
                 // Note the current mods' compatibility for the NewlyCompatible filter
@@ -80,6 +81,10 @@ private void UpdateRepo(object sender, DoWorkEventArgs e)
                 RepoUpdateResult result = Repo.UpdateAllRepositories(
                     RegistryManager.Instance(CurrentInstance),
                     CurrentInstance, Manager.Cache, GUI.user);
+                if (result == RepoUpdateResult.NoChanges && scanChanged)
+                {
+                    result = RepoUpdateResult.Updated;
+                }
                 e.Result = new KeyValuePair<RepoUpdateResult, Dictionary<string, bool>>(
                     result, oldModules);
             }