Cleanup chat highlighting code (#38235)

* Cache regexes

* Convert static LocManager to resolved

* Use Any instead of Count > 0

* Use var instead of explicit types

* Make _highlights readonly

Content.Client/UserInterface/Systems/Chat/ChatUIController.Highlighting.cs

@@ -14,12 +14,17 @@ namespace Content.Client.UserInterface.Systems.Chat;
 /// </summary>
 public sealed partial class ChatUIController : IOnSystemChanged<CharacterInfoSystem>
 {
+    [Dependency] private readonly ILocalizationManager _loc = default!;
     [UISystemDependency] private readonly CharacterInfoSystem _characterInfo = default!;
 
+    private static readonly Regex StartDoubleQuote = new("\"$");
+    private static readonly Regex EndDoubleQuote = new("^\"|(?<=^@)\"");
+    private static readonly Regex StartAtSign = new("^@");
+
     /// <summary>
     ///     The list of words to be highlighted in the chatbox.
     /// </summary>
-    private List<string> _highlights = new();
+    private readonly List<string> _highlights = new();
 
     /// <summary>
     ///     The string holding the hex color used to highlight words.
@@ -42,7 +47,7 @@ public sealed partial class ChatUIController : IOnSystemChanged<CharacterInfoSys
         _config.OnValueChanged(CCVars.ChatHighlightsColor, (value) => { _highlightsColor = value; }, true);
 
         // Load highlights if any were saved.
-        string highlights = _config.GetCVar(CCVars.ChatHighlights);
+        var highlights = _config.GetCVar(CCVars.ChatHighlights);
 
         if (!string.IsNullOrEmpty(highlights))
         {
@@ -84,12 +89,12 @@ public sealed partial class ChatUIController : IOnSystemChanged<CharacterInfoSys
 
         // We first subdivide the highlights based on newlines to prevent replacing
         // a valid "\n" tag and adding it to the final regex.
-        string[] splittedHighlights = newHighlights.Split('\n', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
+        var splittedHighlights = newHighlights.Split('\n', StringSplitOptions.RemoveEmptyEntries | StringSplitOptions.TrimEntries);
 
-        for (int i = 0; i < splittedHighlights.Length; i++)
+        for (var i = 0; i < splittedHighlights.Length; i++)
         {
             // Replace every "\" character with a "\\" to prevent "\n", "\0", etc...
-            string keyword = splittedHighlights[i].Replace(@"\", @"\\");
+            var keyword = splittedHighlights[i].Replace(@"\", @"\\");
 
             // Escape the keyword to prevent special characters like "(" and ")" to be considered valid regex.
             keyword = Regex.Escape(keyword);
@@ -102,17 +107,17 @@ public sealed partial class ChatUIController : IOnSystemChanged<CharacterInfoSys
             // that make sure the words to match are separated by spaces or punctuation.
             // NOTE: The reason why we don't use \b tags is that \b doesn't match reverse slash characters "\" so
             // a pre-sanitized (see 1.) string like "\[test]" wouldn't get picked up by the \b.
-            if (keyword.Count(c => (c == '"')) > 0)
+            if (keyword.Any(c => c == '"'))
             {
                 // Matches the last double quote character.
-                keyword = Regex.Replace(keyword, "\"$", "(?!\\w)");
+                keyword = StartDoubleQuote.Replace(keyword, "(?!\\w)");
                 // When matching for the first double quote character we also consider the possibility
                 // of the double quote being preceded by a @ character.
-                keyword = Regex.Replace(keyword, "^\"|(?<=^@)\"", "(?<!\\w)");
+                keyword = EndDoubleQuote.Replace(keyword, "(?<!\\w)");
             }
 
             // Make sure any name tagged as ours gets highlighted only when others say it.
-            keyword = Regex.Replace(keyword, "^@", "(?<=(?<=/name.*)|(?<=,.*\"\".*))");
+            keyword = StartAtSign.Replace(keyword, "(?<=(?<=/name.*)|(?<=,.*\"\".*))");
 
             _highlights.Add(keyword);
         }
@@ -132,7 +137,7 @@ public sealed partial class ChatUIController : IOnSystemChanged<CharacterInfoSys
         var (_, job, _, _, entityName) = data;
 
         // Mark this entity's name as our character name for the "UpdateHighlights" function.
-        string newHighlights = "@" + entityName;
+        var newHighlights = "@" + entityName;
 
         // Subdivide the character's name based on spaces or hyphens so that every word gets highlighted.
         if (newHighlights.Count(c => (c == ' ' || c == '-')) == 1)
@@ -144,9 +149,9 @@ public sealed partial class ChatUIController : IOnSystemChanged<CharacterInfoSys
             newHighlights = newHighlights.Split('-')[0] + "\n@" + newHighlights.Split('-')[^1];
 
         // Convert the job title to kebab-case and use it as a key for the loc file.
-        string jobKey = job.Replace(' ', '-').ToLower();
+        var jobKey = job.Replace(' ', '-').ToLower();
 
-        if (Loc.TryGetString($"highlights-{jobKey}", out var jobMatches))
+        if (_loc.TryGetString($"highlights-{jobKey}", out var jobMatches))
             newHighlights += '\n' + jobMatches.Replace(", ", "\n");
 
         UpdateHighlights(newHighlights);