From 71fd96126b6d85704a21c434a7906b539e832ceb Mon Sep 17 00:00:00 2001
From: JungleDruid <3953982+JungleDruid@users.noreply.github.com>
Date: Tue, 27 Feb 2024 11:59:58 +0800
Subject: [PATCH] Add detailed error logging

---
 BG3LocalizationMerger.csproj           |   2 +-
 Dialog.cs                              |   4 +-
 HandleExtractor.cs                     | 205 +++++++++++++++++--------
 MainWindow.xaml                        |   2 +-
 MainWindow.xaml.cs                     |  49 +++++-
 PackageManager.cs                      | 178 +++++++++++++--------
 Resources/Strings/Strings.Designer.cs  |   9 ++
 Resources/Strings/Strings.resx         |   3 +
 Resources/Strings/Strings.zh-Hant.resx |   3 +
 9 files changed, 318 insertions(+), 137 deletions(-)

diff --git a/BG3LocalizationMerger.csproj b/BG3LocalizationMerger.csproj
index 6de1476..e1f7f28 100644
--- a/BG3LocalizationMerger.csproj
+++ b/BG3LocalizationMerger.csproj
@@ -8,7 +8,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <PlatformTarget>x64</PlatformTarget>
     <NeutralLanguage>en</NeutralLanguage>
-    <Version>$(VersionPrefix)1.0.4</Version>
+    <Version>$(VersionPrefix)1.1.0</Version>
     <SignAssembly>False</SignAssembly>
   </PropertyGroup>
 
diff --git a/Dialog.cs b/Dialog.cs
index e7a231a..4494d10 100644
--- a/Dialog.cs
+++ b/Dialog.cs
@@ -113,8 +113,8 @@ ref childrenCount
                 }
             }
 
-            Children = childrenCount == 0 ? Array.Empty<string>() : children[..childrenCount];
-            Texts = textsCount == 0 ? Array.Empty<string>() : texts[..textsCount];
+            Children = childrenCount == 0 ? [] : children[..childrenCount];
+            Texts = textsCount == 0 ? [] : texts[..textsCount];
             Debug.Assert(!string.IsNullOrWhiteSpace(Id));
             shared.Return(children);
             shared.Return(texts);
diff --git a/HandleExtractor.cs b/HandleExtractor.cs
index 63a83a2..e381f5f 100644
--- a/HandleExtractor.cs
+++ b/HandleExtractor.cs
@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text.RegularExpressions;
@@ -48,95 +49,175 @@ internal static partial class HandleExtractor
         )]
         private static partial Regex TooltipFilter();
 
-        public static IEnumerable<string> ExtractCharacterHandles(string path)
+        public static IEnumerable<string>? ExtractCharacterHandles(string path)
         {
-            var text = ReadText(path);
-            if (!TemplateCharacterFilter().IsMatch(text))
-                return Enumerable.Empty<string>();
-            return ExtractHandles(text, CharacterHandles());
+            try
+            {
+                var text = ReadText(path);
+                if (!TemplateCharacterFilter().IsMatch(text))
+                    return Enumerable.Empty<string>();
+                return ExtractHandles(text, CharacterHandles());
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static IEnumerable<string> ExtractWaypointHandles(string path)
+        public static IEnumerable<string>? ExtractWaypointHandles(string path)
         {
-            return ExtractGenericHandles(path);
+            try
+            {
+                return ExtractGenericHandles(path);
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static IEnumerable<string> ExtractQuestMarkerHandles(string path)
+        public static IEnumerable<string>? ExtractQuestMarkerHandles(string path)
         {
-            return ExtractGenericHandles(path);
+            try
+            {
+                return ExtractGenericHandles(path);
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static IEnumerable<string> ExtractBookHandles(string path)
+        public static IEnumerable<string>? ExtractBookHandles(string path)
         {
-            return ExtractGenericHandles(path);
+            try
+            {
+                return ExtractGenericHandles(path);
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static (IEnumerable<string>, IEnumerable<string>) ExtractQuestHandles(string path)
+        public static (IEnumerable<string>, IEnumerable<string>)? ExtractQuestHandles(string path)
         {
-            string text = ReadText(path);
-            MatchCollection matches = QuestHandle().Matches(text);
-            var group = matches.GroupBy(x => x.Groups["Type"].Value);
-            return (
-                group
-                    .FirstOrDefault(x => x.Key == "QuestTitle")
-                    ?.SelectMany(x => x.Groups.Values.Skip(1))
-                    .Select(x => x.Value) ?? Enumerable.Empty<string>(),
-                group
-                    .Where(x => x.Key.EndsWith("Description"))
-                    .SelectMany(x => x)
-                    ?.SelectMany(x => x.Groups.Values.Skip(1))
-                    .Select(x => x.Value) ?? Enumerable.Empty<string>()
-            );
+            try
+            {
+                string text = ReadText(path);
+                MatchCollection matches = QuestHandle().Matches(text);
+                var group = matches.GroupBy(x => x.Groups["Type"].Value);
+                return (
+                    group
+                        .FirstOrDefault(x => x.Key == "QuestTitle")
+                        ?.SelectMany(x => x.Groups.Values.Skip(1))
+                        .Select(x => x.Value) ?? Enumerable.Empty<string>(),
+                    group
+                        .Where(x => x.Key.EndsWith("Description"))
+                        .SelectMany(x => x)
+                        ?.SelectMany(x => x.Groups.Values.Skip(1))
+                        .Select(x => x.Value) ?? Enumerable.Empty<string>()
+                );
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static (IEnumerable<string>, IEnumerable<string>) ExtractStatusHandles(string path)
+        public static (IEnumerable<string>, IEnumerable<string>)? ExtractStatusHandles(string path)
         {
-            string text = ReadText(path);
-            MatchCollection matches = StatusHandle().Matches(text);
-            var group = matches.GroupBy(x => x.Groups["Type"].Value);
-            return (
-                group
-                    .FirstOrDefault(x => x.Key == "DisplayName")
-                    ?.SelectMany(x => x.Groups.Values.Skip(1))
-                    .Select(x => x.Value) ?? Enumerable.Empty<string>(),
-                group
-                    .Where(x => x.Key.EndsWith("Description"))
-                    .SelectMany(x => x)
-                    ?.SelectMany(x => x.Groups.Values.Skip(1))
-                    .Select(x => x.Value) ?? Enumerable.Empty<string>()
-            );
+            try
+            {
+                string text = ReadText(path);
+                MatchCollection matches = StatusHandle().Matches(text);
+                var group = matches.GroupBy(x => x.Groups["Type"].Value);
+                return (
+                    group
+                        .FirstOrDefault(x => x.Key == "DisplayName")
+                        ?.SelectMany(x => x.Groups.Values.Skip(1))
+                        .Select(x => x.Value) ?? Enumerable.Empty<string>(),
+                    group
+                        .Where(x => x.Key.EndsWith("Description"))
+                        .SelectMany(x => x)
+                        ?.SelectMany(x => x.Groups.Values.Skip(1))
+                        .Select(x => x.Value) ?? Enumerable.Empty<string>()
+                );
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static IEnumerable<Group> ExtractItemGroup(string path)
+        public static IEnumerable<Group>? ExtractItemGroup(string path)
         {
-            string text = ReadText(path);
-            if (!TemplateItemFilter().IsMatch(text))
-                return Enumerable.Empty<Group>();
-            MatchCollection matches = TemplateHandles().Matches(text);
-            return matches
-                .SelectMany(x => x.Groups.Values.Skip(1))
-                .Where(x => !string.IsNullOrEmpty(x.Value));
+            try
+            {
+                string text = ReadText(path);
+                if (!TemplateItemFilter().IsMatch(text))
+                    return Enumerable.Empty<Group>();
+                MatchCollection matches = TemplateHandles().Matches(text);
+                return matches
+                    .SelectMany(x => x.Groups.Values.Skip(1))
+                    .Where(x => !string.IsNullOrEmpty(x.Value));
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static IEnumerable<string> ExtractTooltipHandles(string path)
+        public static IEnumerable<string>? ExtractTooltipHandles(string path)
         {
-            string text = ReadText(path);
-            MatchCollection matches = GenericHandle().Matches(text);
-            return matches
-                .Where(x => TooltipFilter().IsMatch(x.Groups[0].Value))
-                .SelectMany(x => x.Groups.Values.Skip(1))
-                .Select(x => x.Value)
-                .Where(x => !string.IsNullOrEmpty(x));
+            try
+            {
+                string text = ReadText(path);
+                MatchCollection matches = GenericHandle().Matches(text);
+                return matches
+                    .Where(x => TooltipFilter().IsMatch(x.Groups[0].Value))
+                    .SelectMany(x => x.Groups.Values.Skip(1))
+                    .Select(x => x.Value)
+                    .Where(x => !string.IsNullOrEmpty(x));
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static IEnumerable<string> ExtractHintHandles(string path)
+        public static IEnumerable<string>? ExtractHintHandles(string path)
         {
-            return ExtractGenericHandles(path);
+            try
+            {
+                return ExtractGenericHandles(path);
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
-        public static IEnumerable<string> ExtractGenericHandles(string path)
+        public static IEnumerable<string>? ExtractGenericHandles(string path)
         {
-            return ExtractHandles(ReadText(path), GenericHandle());
+            try
+            {
+                return ExtractHandles(ReadText(path), GenericHandle());
+            }
+            catch (Exception e)
+            {
+                MainWindow.LogFileError(path, e);
+                return null;
+            }
         }
 
         private static string ReadText(string path)
diff --git a/MainWindow.xaml b/MainWindow.xaml
index 67209a0..ed929de 100644
--- a/MainWindow.xaml
+++ b/MainWindow.xaml
@@ -43,7 +43,7 @@
                 <RowDefinition Height="70"/>
                 <RowDefinition/>
             </Grid.RowDefinitions>
-            <TextBox x:Name="LogTextBox" Grid.Row="6" TextWrapping="Wrap" Text="" Grid.ColumnSpan="3" IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
+            <RichTextBox x:Name="LogTextBox" Grid.Row="6" Grid.ColumnSpan="3" IsReadOnly="True" VerticalScrollBarVisibility="Visible"/>
             <Label Content="{ns:Loc UnpackedData}" VerticalContentAlignment="Center" Margin="10,10,10,10"/>
             <Label Content="{ns:Loc LanguagePack}" VerticalContentAlignment="Center" Grid.Row="1" Margin="10,10,10,10"/>
             <Label Content="{ns:Loc ReferencePack}" VerticalContentAlignment="Center" Grid.Row="2" Margin="10,10,10,10"/>
diff --git a/MainWindow.xaml.cs b/MainWindow.xaml.cs
index 1c86041..6da50fd 100644
--- a/MainWindow.xaml.cs
+++ b/MainWindow.xaml.cs
@@ -4,6 +4,7 @@
 using Ookii.Dialogs.Wpf;
 using System;
 using System.Collections.Generic;
+using System.Collections.Immutable;
 using System.Diagnostics;
 using System.Globalization;
 using System.IO;
@@ -13,6 +14,7 @@
 using System.Threading.Tasks;
 using System.Windows;
 using System.Windows.Controls;
+using System.Windows.Documents;
 using System.Windows.Media;
 
 namespace BG3LocalizationMerger
@@ -26,6 +28,9 @@ public partial class MainWindow
 
         public static MainWindow Instance => s_instance!;
 
+        public static int ErrorCount { get; private set; }
+        public static bool CacheValid { get; private set; }
+
         public MainWindow()
         {
             s_instance = this;
@@ -100,26 +105,60 @@ private void InitCulture()
             LanguageComboBox.SelectedIndex = 0;
         }
 
-        public static void Log(string text)
+        public static void Log(string text, Brush? foreground = null)
         {
             s_instance!.Dispatcher.Invoke(() =>
             {
                 var textbox = s_instance.LogTextBox;
-                text = $"[{DateTime.Now.ToLongTimeString()}] {text}";
-                if (!string.IsNullOrEmpty(textbox.Text))
-                    text = '\n' + text;
-                textbox.Text += text;
+                Paragraph paragraph = new();
+                Run run = new($"[{DateTime.Now.ToLongTimeString()}] {text}");
+                paragraph.Inlines.Add(run);
+                paragraph.Margin = new(0);
+                if (foreground != null)
+                {
+                    paragraph.Foreground = foreground;
+                }
+                textbox.Document.Blocks.Add(paragraph);
                 textbox.ScrollToEnd();
             });
         }
 
+        public static void LogError(string text)
+        {
+            ErrorCount += 1;
+            Log(text, Brushes.Red);
+        }
+
+        public static void LogFileError(string path, Exception e)
+        {
+            LogError($"ERROR: {e.Message} ({path[Settings.Default.UnpackedDataPath.Length..]})");
+        }
+
         private async void Merge_Click(object sender, RoutedEventArgs e)
         {
             if (!await VerifyTextBoxes(true))
                 return;
             SaveSettings();
 
+            ErrorCount = 0;
+            LogTextBox.Document.Blocks.Clear();
+
             await RunMerge(PackageManager.Instance.Merge);
+
+            if (ErrorCount > 0)
+            {
+                CacheValid = false;
+                MessageBox.Show(
+                    $"{ErrorCount} error{(ErrorCount > 1 ? "s" : "")} occurred. Check the logs for details.",
+                    "Error",
+                    MessageBoxButton.OK,
+                    MessageBoxImage.Error
+                );
+            }
+            else
+            {
+                CacheValid = true;
+            }
         }
 
         private Task<bool> VerifyTextBoxes(bool showWarning, bool checkUnpackedData = true)
diff --git a/PackageManager.cs b/PackageManager.cs
index 625efbc..c214e81 100644
--- a/PackageManager.cs
+++ b/PackageManager.cs
@@ -17,19 +17,19 @@ namespace BG3LocalizationMerger
 {
     internal sealed partial class PackageManager : SingletonBase<PackageManager>
     {
-        internal static readonly ImmutableList<string> s_modNames = new List<string>()
-        {
+        internal static readonly ImmutableList<string> s_modNames =
+        [
             "Shared",
             "SharedDev",
             "Gustav",
             "GustavDev"
-        }.ToImmutableList();
+        ];
 
-        private static readonly string[] s_questPrototypeFiles = new string[]
-        {
+        private static readonly string[] s_questPrototypeFiles =
+        [
             "quest_prototypes.lsx",
             "objective_prototypes.lsx"
-        };
+        ];
 
         public IReadOnlyDictionary<string, Dialog>? Dialogs { get; private set; }
         public ISet<string>? ItemNameHandles { get; private set; }
@@ -51,6 +51,11 @@ internal sealed partial class PackageManager : SingletonBase<PackageManager>
 
         public void Load(CancellationToken cancellationToken)
         {
+            if (MainWindow.CacheValid)
+            {
+                MainWindow.Log(Strings.UsingCache);
+            }
+
             LoadItems(cancellationToken);
             LoadCharacters(cancellationToken);
             LoadDialogues(cancellationToken);
@@ -71,15 +76,21 @@ private static void LogLoading(string text)
 
         private static void LogLoaded(int amount, string text, TimeSpan elapsed)
         {
-            MainWindow.Log(
-                string.Format(Strings.LoadedMessage, amount, text, elapsed.TotalSeconds)
-            );
+            string message = string.Format(Strings.LoadedMessage, amount, text, elapsed.TotalSeconds);
+            if (amount > 0)
+            {
+                MainWindow.Log(message);
+            }
+            else
+            {
+                MainWindow.LogError(message);
+            }
         }
 
         private void LoadCharacters(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeCharacters || CharacterHandles != null)
+            if (MainWindow.CacheValid && !props.MergeCharacters || CharacterHandles != null)
                 return;
 
             LogLoading(Strings.Characters);
@@ -130,7 +141,9 @@ private void LoadCharacters(CancellationToken cancellationToken)
                 .Concat(levelMergedFiles)
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .SelectMany(HandleExtractor.ExtractCharacterHandles)
+                .Select(HandleExtractor.ExtractCharacterHandles)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .ToHashSet();
 
             sw.Stop();
@@ -140,7 +153,7 @@ private void LoadCharacters(CancellationToken cancellationToken)
         private void LoadMiscs(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeMiscs || MiscHandles != null)
+            if (MainWindow.CacheValid && !props.MergeMiscs || MiscHandles != null)
                 return;
 
             LogLoading(Strings.Miscs);
@@ -161,7 +174,9 @@ private void LoadMiscs(CancellationToken cancellationToken)
             MiscHandles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .SelectMany(HandleExtractor.ExtractGenericHandles)
+                .Select(HandleExtractor.ExtractGenericHandles)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .ToHashSet();
 
             sw.Stop();
@@ -171,7 +186,7 @@ private void LoadMiscs(CancellationToken cancellationToken)
         private void LoadWaypoints(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeWaypoints || WaypointHandles != null)
+            if (MainWindow.CacheValid && !props.MergeWaypoints || WaypointHandles != null)
                 return;
 
             LogLoading(Strings.Waypoints);
@@ -195,7 +210,9 @@ private void LoadWaypoints(CancellationToken cancellationToken)
             WaypointHandles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .SelectMany(HandleExtractor.ExtractWaypointHandles)
+                .Select(HandleExtractor.ExtractWaypointHandles)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .ToHashSet();
 
             sw.Stop();
@@ -205,7 +222,7 @@ private void LoadWaypoints(CancellationToken cancellationToken)
         private void LoadQuestMarkers(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeQuestMarkers || QuestMarkerHandles != null)
+            if (MainWindow.CacheValid && !props.MergeQuestMarkers || QuestMarkerHandles != null)
                 return;
 
             LogLoading(Strings.QuestMarkers);
@@ -227,7 +244,9 @@ private void LoadQuestMarkers(CancellationToken cancellationToken)
             QuestMarkerHandles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .SelectMany(HandleExtractor.ExtractQuestMarkerHandles)
+                .Select(HandleExtractor.ExtractQuestMarkerHandles)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .ToHashSet();
 
             sw.Stop();
@@ -237,8 +256,8 @@ private void LoadQuestMarkers(CancellationToken cancellationToken)
         private void LoadQuests(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (
-                (!props.MergeQuestNames || QuestNameHandles != null)
+            if (MainWindow.CacheValid
+                && (!props.MergeQuestNames || QuestNameHandles != null)
                 && (!props.MergeQuestDescriptions || QuestDescriptionHandles != null)
             )
                 return;
@@ -264,7 +283,9 @@ private void LoadQuests(CancellationToken cancellationToken)
             var handles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .Select(HandleExtractor.ExtractQuestHandles);
+                .Select(HandleExtractor.ExtractQuestHandles)
+                .Where(x => x != null)
+                .Select(x => ((IEnumerable<string>, IEnumerable<string>))x!);
 
             QuestNameHandles = handles.SelectMany(x => x.Item1).ToHashSet();
             QuestDescriptionHandles = handles.SelectMany(x => x.Item2).ToHashSet();
@@ -280,8 +301,8 @@ private void LoadQuests(CancellationToken cancellationToken)
         private void LoadStatus(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (
-                (!props.MergeStatusNames || StatusNameHandles != null)
+            if (MainWindow.CacheValid
+                && (!props.MergeStatusNames || StatusNameHandles != null)
                 && (!props.MergeStatusDescriptions || StatusDescriptionHandles != null)
             )
                 return;
@@ -305,7 +326,9 @@ private void LoadStatus(CancellationToken cancellationToken)
             var handles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .Select(HandleExtractor.ExtractStatusHandles);
+                .Select(HandleExtractor.ExtractStatusHandles)
+                .Where(x => x != null)
+                .Select(x => ((IEnumerable<string>, IEnumerable<string>))x!);
 
             StatusNameHandles = handles.SelectMany(x => x.Item1).ToHashSet();
             StatusDescriptionHandles = handles.SelectMany(x => x.Item2).ToHashSet();
@@ -321,7 +344,7 @@ private void LoadStatus(CancellationToken cancellationToken)
         private void LoadHints(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeHints || HintsHandles != null)
+            if (MainWindow.CacheValid && !props.MergeHints || HintsHandles != null)
                 return;
 
             LogLoading(Strings.Hints);
@@ -336,7 +359,9 @@ private void LoadHints(CancellationToken cancellationToken)
             HintsHandles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .SelectMany(HandleExtractor.ExtractHintHandles)
+                .Select(HandleExtractor.ExtractHintHandles)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .ToHashSet();
 
             sw.Stop();
@@ -346,7 +371,7 @@ private void LoadHints(CancellationToken cancellationToken)
         private void LoadTooltips(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeTooltips || TooltipHandles != null)
+            if (MainWindow.CacheValid && !props.MergeTooltips || TooltipHandles != null)
                 return;
 
             LogLoading(Strings.Tooltips);
@@ -361,7 +386,9 @@ private void LoadTooltips(CancellationToken cancellationToken)
             TooltipHandles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .SelectMany(HandleExtractor.ExtractTooltipHandles)
+                .Select(HandleExtractor.ExtractTooltipHandles)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .ToHashSet();
 
             sw.Stop();
@@ -371,7 +398,7 @@ private void LoadTooltips(CancellationToken cancellationToken)
         private void LoadBooks(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeBooks || BookHandles != null)
+            if (MainWindow.CacheValid && !props.MergeBooks || BookHandles != null)
                 return;
 
             LogLoading(Strings.Books);
@@ -392,7 +419,9 @@ private void LoadBooks(CancellationToken cancellationToken)
             BookHandles = files
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .SelectMany(HandleExtractor.ExtractBookHandles)
+                .Select(HandleExtractor.ExtractBookHandles)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .ToHashSet();
 
             sw.Stop();
@@ -402,8 +431,8 @@ private void LoadBooks(CancellationToken cancellationToken)
         private void LoadItems(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (
-                (!props.MergeItemNames || ItemNameHandles != null)
+            if (MainWindow.CacheValid
+                && (!props.MergeItemNames || ItemNameHandles != null)
                 && (!props.MergeItemDescriptions || ItemDescriptionHandles != null)
             )
                 return;
@@ -456,7 +485,9 @@ private void LoadItems(CancellationToken cancellationToken)
                 .Concat(levelMergedFiles)
                 .AsParallel()
                 .WithCancellation(cancellationToken)
-                .Select(HandleExtractor.ExtractItemGroup);
+                .Select(HandleExtractor.ExtractItemGroup)
+                .Where(x => x != null)
+                .Select(x => x!);
 
             ItemNameHandles = groups
                 .SelectMany(x => x.Where(x => x.Name == "Name").Select(x => x.Value))
@@ -466,6 +497,7 @@ private void LoadItems(CancellationToken cancellationToken)
                 .ToHashSet();
 
             sw.Stop();
+
             LogLoaded(
                 ItemNameHandles?.Count ?? ItemDescriptionHandles!.Count,
                 Strings.Items,
@@ -476,7 +508,7 @@ private void LoadItems(CancellationToken cancellationToken)
         private void LoadDialogues(CancellationToken cancellationToken)
         {
             var props = Properties.Settings.Default;
-            if (!props.MergeDialogues || Dialogs != null)
+            if (MainWindow.CacheValid && !props.MergeDialogues || Dialogs != null)
                 return;
 
             LogLoading(Strings.Dialogues);
@@ -500,41 +532,55 @@ private void LoadDialogues(CancellationToken cancellationToken)
                 .WithCancellation(cancellationToken)
                 .Select(lsx =>
                 {
-                    XmlReader reader = XmlReader.Create(
-                        lsx,
-                        new XmlReaderSettings { IgnoreWhitespace = true }
-                    );
-                    if (!reader.ReadToFollowing("save") || !reader.ReadToDescendant("region"))
-                        throw new InvalidOperationException();
-                    while (reader.GetAttribute("id") != "dialog")
-                        reader.Skip();
-                    if (!reader.ReadToDescendant("children"))
-                        throw new InvalidOperationException();
-                    reader = reader.ReadSubtree();
-                    if (!reader.ReadToDescendant("node"))
-                        throw new InvalidOperationException();
-                    do
+                    XmlReader? reader = null;
+                    try
                     {
-                        if (reader.NodeType != XmlNodeType.Element || reader.IsEmptyElement)
+                        reader = XmlReader.Create(
+                            lsx,
+                            new XmlReaderSettings { IgnoreWhitespace = true }
+                        );
+                        if (!reader.ReadToFollowing("save") || !reader.ReadToDescendant("region"))
+                            throw new InvalidOperationException();
+                        while (reader.GetAttribute("id") != "dialog")
+                            reader.Skip();
+                        if (!reader.ReadToDescendant("children"))
+                            throw new InvalidOperationException();
+                        reader = reader.ReadSubtree();
+                        if (!reader.ReadToDescendant("node"))
+                            throw new InvalidOperationException();
+                        do
                         {
-                            reader.Read();
-                            continue;
-                        }
-                        Debug.Assert(reader.Name == "node");
-                        string? id = reader.GetAttribute("id");
-                        switch (id)
-                        {
-                            case "nodes":
-                                var dialogs = ParseDialogs(reader.ReadSubtree());
-                                return dialogs;
-                            default:
-                                reader.Skip();
-                                break;
-                        }
-                    } while (reader.NodeType == XmlNodeType.Element || reader.Read());
-                    throw new InvalidOperationException();
+                            if (reader.NodeType != XmlNodeType.Element || reader.IsEmptyElement)
+                            {
+                                reader.Read();
+                                continue;
+                            }
+                            Debug.Assert(reader.Name == "node");
+                            string? id = reader.GetAttribute("id");
+                            switch (id)
+                            {
+                                case "nodes":
+                                    var dialogs = ParseDialogs(reader.ReadSubtree()).ToArray();
+                                    return dialogs;
+                                default:
+                                    reader.Skip();
+                                    break;
+                            }
+                        } while (reader.NodeType == XmlNodeType.Element || reader.Read());
+                        throw new InvalidOperationException();
+                    }
+                    catch (Exception e)
+                    {
+                        MainWindow.LogFileError(lsx, e);
+                        return null;
+                    }
+                    finally
+                    {
+                        reader?.Close();
+                    }
                 })
-                .SelectMany(x => x)
+                .Where(x => x != null)
+                .SelectMany(x => x!)
                 .GroupBy(x => x.Id)
                 .Select(x => x.Last())
                 .ToDictionary(x => x.Id);
@@ -656,7 +702,7 @@ public async Task Save(CancellationToken cancellationToken)
                     try
                     {
                         cancellationToken.ThrowIfCancellationRequested();
-                        packager.CreatePackage(exportPath, _dir, options);
+                        await packager.CreatePackage(exportPath, _dir, options);
                         break;
                     }
                     catch (IOException)
diff --git a/Resources/Strings/Strings.Designer.cs b/Resources/Strings/Strings.Designer.cs
index 88bbc81..8949434 100644
--- a/Resources/Strings/Strings.Designer.cs
+++ b/Resources/Strings/Strings.Designer.cs
@@ -507,6 +507,15 @@ public static string UnpackedData {
             }
         }
         
+        /// <summary>
+        ///   Looks up a localized string similar to Using cached data from the previous merge. (To discard the cache, please relaunch the program.).
+        /// </summary>
+        public static string UsingCache {
+            get {
+                return ResourceManager.GetString("UsingCache", resourceCulture);
+            }
+        }
+        
         /// <summary>
         ///   Looks up a localized string similar to Waypoints.
         /// </summary>
diff --git a/Resources/Strings/Strings.resx b/Resources/Strings/Strings.resx
index b454a56..0e498bc 100644
--- a/Resources/Strings/Strings.resx
+++ b/Resources/Strings/Strings.resx
@@ -256,4 +256,7 @@ Retry?</value>
   <data name="TotalElapsedMessage" xml:space="preserve">
     <value>Total elapsed: {0:0.##}s</value>
   </data>
+  <data name="UsingCache" xml:space="preserve">
+    <value>Using cached data from the previous merge. (To discard the cache, please relaunch the program.)</value>
+  </data>
 </root>
\ No newline at end of file
diff --git a/Resources/Strings/Strings.zh-Hant.resx b/Resources/Strings/Strings.zh-Hant.resx
index 69ce265..f8d9de2 100644
--- a/Resources/Strings/Strings.zh-Hant.resx
+++ b/Resources/Strings/Strings.zh-Hant.resx
@@ -256,4 +256,7 @@
   <data name="TotalElapsedMessage" xml:space="preserve">
     <value>總共耗時：{0:0.##}秒</value>
   </data>
+  <data name="UsingCache" xml:space="preserve">
+    <value>正在使用上次合併的暫存資料。（若要捨棄暫存資料，請重啟本程式）</value>
+  </data>
 </root>
\ No newline at end of file