From d65d23ffceb77a5deaa895619be9b74230c03e92 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20Br=C3=BCbach?= <Bruebach.Lukas@bdosecurity.de>
Date: Mon, 21 Sep 2026 13:20:52 +0200
Subject: [PATCH] [Card] Search cards by Scryfall Tagger tag

---
 cockatrice/resources/help/search.md           |  5 +++
 .../libcockatrice/filters/filter_string.cpp   | 18 +++++++-
 tests/carddatabase/filter_string_test.cpp     | 41 +++++++++++++++++++
 3 files changed, 63 insertions(+), 1 deletion(-)

diff --git a/cockatrice/resources/help/search.md b/cockatrice/resources/help/search.md
index fd0a12507..2d35b7b25 100644
--- a/cockatrice/resources/help/search.md
+++ b/cockatrice/resources/help/search.md
@@ -22,6 +22,11 @@ In this list of examples below, each entry has an explanation and can be clicked
 <dd>[t:basic](#t:basic) <small>(Any card with the type basic)</small></dd>
 <dd>[t:arcane t:instant](#t:arcane t:instant) <small>(Any card with the types arcane and instant)</small></dd>
 
+<dt>Tags:</dt>
+<dd>[tags:ramp](#tags:ramp) <small>(Any card tagged "ramp" by the Scryfall Tagger community)</small></dd>
+<dd>[tags:draw tags:ramp](#tags:draw tags:ramp) <small>(Any card tagged both "draw" and "ramp")</small></dd>
+<dd>[tags:draw OR tags:ramp](#tags:draw OR tags:ramp) <small>(Any card tagged "draw" or "ramp")</small></dd>
+
 <dt><u>C</u>olors:</dt>
 <dd>[c:w](#c:w) <small>(Any card that is white)</small></dd>
 <dd>[c:wu](#c:wu) <small>(Any card that is white or blue)</small></dd>
diff --git a/libcockatrice_filters/libcockatrice/filters/filter_string.cpp b/libcockatrice_filters/libcockatrice/filters/filter_string.cpp
index 1b63ca122..f9febbbbe 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_string.cpp
+++ b/libcockatrice_filters/libcockatrice/filters/filter_string.cpp
@@ -6,6 +6,7 @@
 #include <QString>
 #include <functional>
 #include <libcockatrice/card/database/card_database_manager.h>
+#include <libcockatrice/card/game_specific_terms.h>
 #include <libcockatrice/utility/peglib.h>
 
 static peg::parser search(R"(
@@ -17,7 +18,7 @@ ComplexQueryPart <- SomewhatComplexQueryPart ws "OR" ws ComplexQueryPart / Somew
 
 SomewhatComplexQueryPart <- [(] QueryPartList [)] / QueryPart
 
-QueryPart <- NotQuery / SetQuery / RarityQuery / CMCQuery / FormatQuery / PowerQuery / ToughnessQuery / ColorQuery / TypeQuery / OracleQuery / FieldQuery / GenericQuery
+QueryPart <- NotQuery / SetQuery / RarityQuery / CMCQuery / FormatQuery / PowerQuery / ToughnessQuery / ColorQuery / TagQuery / TypeQuery / OracleQuery / FieldQuery / GenericQuery
 
 NotQuery <- ('NOT' ws/'-') SomewhatComplexQueryPart
 SetQuery <- ('e'/'set') SetExpression / ([:] FlexStringValue)
@@ -38,6 +39,8 @@ Legality <- [Ll] 'egal'? / [Bb] 'anned'? / [Rr] 'estricted'
 
 TypeQuery <- [tT] 'ype'? [:] StringValue
 
+TagQuery <- [tT]('ags'/'ag') [:] String
+
 Color <- < [Ww] 'hite'? / [Uu] / [Bb] 'lack'? / [Rr] 'ed'? / [Gg] 'reen'?  / [Bb] 'lue'? >
 ColorEx <- Color / [mc]
 
@@ -133,6 +136,19 @@ static void setupParserRules()
         const auto matcher = std::any_cast<StringMatcher>(sv[0]);
         return [=](const CardData &x) -> bool { return matcher(x->getCardType()); };
     };
+    search["TagQuery"] = [](const peg::SemanticValues &sv) -> Filter {
+        // Tags are stored space-separated, so matching whole tokens keeps
+        // `tags:ram` from matching `ramp`. Combine tags with AND:
+        // `tags:draw tags:ramp`.
+        const auto tag = std::any_cast<QString>(sv[0]).trimmed();
+        return [=](const CardData &x) -> bool {
+            const QString stored = x->getProperty(Mtg::Tags);
+            if (stored.isEmpty() || tag.isEmpty()) {
+                return false;
+            }
+            return stored.split(" ", Qt::SkipEmptyParts).contains(tag, Qt::CaseInsensitive);
+        };
+    };
     search["SetQuery"] = [](const peg::SemanticValues &sv) -> Filter {
         if (sv.choice() == 1) {
             auto matcher = std::any_cast<StringMatcher>(sv[0]);
diff --git a/tests/carddatabase/filter_string_test.cpp b/tests/carddatabase/filter_string_test.cpp
index 2b92c65df..400b67caa 100644
--- a/tests/carddatabase/filter_string_test.cpp
+++ b/tests/carddatabase/filter_string_test.cpp
@@ -124,6 +124,47 @@ TEST_F(CardQuery, SearchLanguageIsBoundPerInstance)
     ASSERT_TRUE(germanQuery.check(localized));
 }
 
+CardInfoPtr taggedCard()
+{
+    return CardInfo::newInstance("Tagged Card", "text", false, {{"tags", "ramp removal"}}, {}, {}, {}, {});
+}
+
+TEST_F(CardQuery, TagsMatchWholeSlugs)
+{
+    const CardData tagged = taggedCard();
+    ASSERT_TRUE(FilterString("tags:ramp").check(tagged));
+    ASSERT_TRUE(FilterString("tags:removal").check(tagged));
+    ASSERT_TRUE(FilterString("tags:RAMP").check(tagged));
+    ASSERT_TRUE(FilterString("tag:ramp").check(tagged));
+    ASSERT_FALSE(FilterString("tags:squirrel").check(tagged));
+}
+
+TEST_F(CardQuery, TagQueryDoesNotMatchPartialSlugs)
+{
+    const CardData tagged = taggedCard();
+    ASSERT_FALSE(FilterString("tags:ram").check(tagged));
+    ASSERT_FALSE(FilterString("tags:mov").check(tagged));
+}
+
+TEST_F(CardQuery, TagQueryCombinesWithAnd)
+{
+    const CardData tagged = taggedCard();
+    ASSERT_TRUE(FilterString("tags:ramp tags:removal").check(tagged));
+    ASSERT_FALSE(FilterString("tags:ramp tags:squirrel").check(tagged));
+}
+
+TEST_F(CardQuery, TagQueryTreatsCommasAsPartOfTheSlug)
+{
+    // Tag lists are not a thing: `tags:draw` and `tags:ramp` are separate terms.
+    const CardData tagged = taggedCard();
+    ASSERT_FALSE(FilterString("tags:ramp,removal").check(tagged));
+}
+
+TEST_F(CardQuery, TagQueryFalseWhenCardHasNoTags)
+{
+    ASSERT_FALSE(FilterString("tags:ramp").check(cat));
+}
+
 } // namespace
 
 int main(int argc, char **argv)