From c423f77d535b33a07d5930ea73499d0e621069f9 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 27 Jun 2023 15:34:33 +0900
Subject: [PATCH] Add support for matching full terms using suffixed `!`

---
 osu.Game/Screens/Select/FilterCriteria.cs    | 53 +++++++++++++++++---
 osu.Game/Screens/Select/FilterQueryParser.cs |  2 +-
 2 files changed, 47 insertions(+), 8 deletions(-)

diff --git a/osu.Game/Screens/Select/FilterCriteria.cs b/osu.Game/Screens/Select/FilterCriteria.cs
index 22780acfc3..c8804528c7 100644
--- a/osu.Game/Screens/Select/FilterCriteria.cs
+++ b/osu.Game/Screens/Select/FilterCriteria.cs
@@ -3,6 +3,7 @@
 
 using System;
 using System.Collections.Generic;
+using System.Globalization;
 using System.Linq;
 using System.Text.RegularExpressions;
 using osu.Game.Beatmaps;
@@ -62,7 +63,7 @@ namespace osu.Game.Screens.Select
                 string remainingText = value;
 
                 // First handle quoted segments to ensure we keep inline spaces in exact matches.
-                foreach (Match quotedSegment in Regex.Matches(searchText, "(\"[^\"]+\")"))
+                foreach (Match quotedSegment in Regex.Matches(searchText, "(\"[^\"]+\"[!]?)"))
                 {
                     terms.Add(new OptionalTextFilter { SearchTerm = quotedSegment.Value });
                     remainingText = remainingText.Replace(quotedSegment.Value, string.Empty);
@@ -138,7 +139,7 @@ namespace osu.Game.Screens.Select
         {
             public bool HasFilter => !string.IsNullOrEmpty(SearchTerm);
 
-            public bool Exact { get; private set; }
+            public MatchMode MatchMode { get; private set; }
 
             public bool Matches(string value)
             {
@@ -149,10 +150,18 @@ namespace osu.Game.Screens.Select
                 if (string.IsNullOrEmpty(value))
                     return false;
 
-                if (Exact)
-                    return Regex.IsMatch(value, $@"(^|\s){Regex.Escape(searchTerm)}($|\s)", RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
+                switch (MatchMode)
+                {
+                    default:
+                    case MatchMode.None:
+                        return value.Contains(SearchTerm, StringComparison.InvariantCultureIgnoreCase);
 
-                return value.Contains(SearchTerm, StringComparison.InvariantCultureIgnoreCase);
+                    case MatchMode.IsolatedPhrase:
+                        return Regex.IsMatch(value, $@"(^|\s){Regex.Escape(searchTerm)}($|\s)", RegexOptions.IgnoreCase | RegexOptions.CultureInvariant);
+
+                    case MatchMode.FullPhrase:
+                        return CultureInfo.InvariantCulture.CompareInfo.Compare(value, searchTerm, CompareOptions.IgnoreCase) == 0;
+                }
             }
 
             private string searchTerm;
@@ -162,12 +171,42 @@ namespace osu.Game.Screens.Select
                 get => searchTerm;
                 set
                 {
-                    searchTerm = value.Trim('"');
-                    Exact = searchTerm != value;
+                    searchTerm = value;
+
+                    if (searchTerm.EndsWith("\"!", StringComparison.Ordinal))
+                    {
+                        searchTerm = searchTerm.Trim('!', '\"');
+                        MatchMode = MatchMode.FullPhrase;
+                    }
+                    else if (searchTerm.StartsWith('\"'))
+                    {
+                        searchTerm = searchTerm.Trim('\"');
+                        MatchMode = MatchMode.IsolatedPhrase;
+                    }
+                    else
+                        MatchMode = MatchMode.None;
                 }
             }
 
             public bool Equals(OptionalTextFilter other) => SearchTerm == other.SearchTerm;
         }
+
+        public enum MatchMode
+        {
+            /// <summary>
+            /// Match using a simple "contains" substring match.
+            /// </summary>
+            None,
+
+            /// <summary>
+            /// Match for the search phrase being isolated by spaces, or at the start or end of the text.
+            /// </summary>
+            IsolatedPhrase,
+
+            /// <summary>
+            /// Match for the search phrase matching the full text in completion.
+            /// </summary>
+            FullPhrase,
+        }
     }
 }
diff --git a/osu.Game/Screens/Select/FilterQueryParser.cs b/osu.Game/Screens/Select/FilterQueryParser.cs
index 474a9fdfea..4bc4448291 100644
--- a/osu.Game/Screens/Select/FilterQueryParser.cs
+++ b/osu.Game/Screens/Select/FilterQueryParser.cs
@@ -16,7 +16,7 @@ namespace osu.Game.Screens.Select
     public static class FilterQueryParser
     {
         private static readonly Regex query_syntax_regex = new Regex(
-            @"\b(?<key>\w+)(?<op>(:|=|(>|<)(:|=)?))(?<value>("".*"")|(\S*))",
+            @"\b(?<key>\w+)(?<op>(:|=|(>|<)(:|=)?))(?<value>("".*""[!]?)|(\S*))",
             RegexOptions.Compiled | RegexOptions.IgnoreCase);
 
         internal static void ApplyQueries(FilterCriteria criteria, string query)