From 0ea0e231bf71a113d51fa9ba1147b245536ba3bf Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Lukas=20Br=C3=BCbach?= <Bruebach.Lukas@bdosecurity.de>
Date: Mon, 21 Sep 2026 13:21:00 +0200
Subject: [PATCH] [Card] Add a Tag attribute to the card filter tree

---
 .../libcockatrice/filters/filter_card.cpp      |  2 ++
 .../libcockatrice/filters/filter_card.h        |  1 +
 .../libcockatrice/filters/filter_tree.cpp      | 13 +++++++++++++
 .../libcockatrice/filters/filter_tree.h        |  1 +
 tests/carddatabase/filter_string_test.cpp      | 18 ++++++++++++++++++
 5 files changed, 35 insertions(+)

diff --git a/libcockatrice_filters/libcockatrice/filters/filter_card.cpp b/libcockatrice_filters/libcockatrice/filters/filter_card.cpp
index 5fdce7ae0..409182b5f 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_card.cpp
+++ b/libcockatrice_filters/libcockatrice/filters/filter_card.cpp
@@ -84,6 +84,8 @@ const QString CardFilter::attrName(Attr a)
             return tr("Loyalty");
         case AttrFormat:
             return tr("Format");
+        case AttrTag:
+            return tr("Tag");
         case AttrMainType:
             return tr("Main Type");
         case AttrSubType:
diff --git a/libcockatrice_filters/libcockatrice/filters/filter_card.h b/libcockatrice_filters/libcockatrice/filters/filter_card.h
index bb1e0ef53..2eab5508c 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_card.h
+++ b/libcockatrice_filters/libcockatrice/filters/filter_card.h
@@ -43,6 +43,7 @@ public:
         AttrMainType,
         AttrSubType,
         AttrFormat,
+        AttrTag,
         AttrEnd,
     };
 
diff --git a/libcockatrice_filters/libcockatrice/filters/filter_tree.cpp b/libcockatrice_filters/libcockatrice/filters/filter_tree.cpp
index a5d91d9d3..1c0d488e1 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_tree.cpp
+++ b/libcockatrice_filters/libcockatrice/filters/filter_tree.cpp
@@ -3,6 +3,7 @@
 #include "filter_card.h"
 
 #include <QList>
+#include <libcockatrice/card/game_specific_terms.h>
 
 template <class T> FilterTreeNode *FilterTreeBranch<T>::nodeAt(int i) const
 {
@@ -341,6 +342,16 @@ bool FilterItem::acceptFormat(const CardInfoPtr info) const
     return info->getLegalityProp(term.toLower()) == "legal";
 }
 
+bool FilterItem::acceptTag(const CardInfoPtr info) const
+{
+    const QString stored = info->getProperty(Mtg::Tags);
+    if (stored.isEmpty()) {
+        return false;
+    }
+    // Tags are stored space-separated; match whole slugs, not substrings.
+    return stored.split(" ", Qt::SkipEmptyParts).contains(term.trimmed(), Qt::CaseInsensitive);
+}
+
 bool FilterItem::acceptLoyalty(const CardInfoPtr info) const
 {
     if (info->getLoyalty().isEmpty()) {
@@ -495,6 +506,8 @@ bool FilterItem::acceptCardAttr(const CardInfoPtr info,
             return acceptLoyalty(info);
         case CardFilter::AttrFormat:
             return acceptFormat(info);
+        case CardFilter::AttrTag:
+            return acceptTag(info);
         case CardFilter::AttrMainType:
             return acceptMainType(info);
         case CardFilter::AttrSubType:
diff --git a/libcockatrice_filters/libcockatrice/filters/filter_tree.h b/libcockatrice_filters/libcockatrice/filters/filter_tree.h
index dd47a1ebc..3f9f0f8a4 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_tree.h
+++ b/libcockatrice_filters/libcockatrice/filters/filter_tree.h
@@ -228,6 +228,7 @@ public:
     [[nodiscard]] bool
     acceptCardAttr(CardInfoPtr info, CardFilter::Attr attr, const CardSearchLanguage &searchLanguage) const;
     [[nodiscard]] bool acceptFormat(CardInfoPtr info) const;
+    [[nodiscard]] bool acceptTag(CardInfoPtr info) const;
     [[nodiscard]] bool relationCheck(int cardInfo) const;
 };
 
diff --git a/tests/carddatabase/filter_string_test.cpp b/tests/carddatabase/filter_string_test.cpp
index 400b67caa..5a3e6156d 100644
--- a/tests/carddatabase/filter_string_test.cpp
+++ b/tests/carddatabase/filter_string_test.cpp
@@ -3,6 +3,7 @@
 
 #include "gtest/gtest.h"
 #include <libcockatrice/filters/filter_string.h>
+#include <libcockatrice/filters/filter_tree.h>
 #include <libcockatrice/interfaces/noop_card_preference_provider.h>
 #include <libcockatrice/interfaces/noop_card_set_priority_controller.h>
 
@@ -160,6 +161,23 @@ TEST_F(CardQuery, TagQueryTreatsCommasAsPartOfTheSlug)
     ASSERT_FALSE(FilterString("tags:ramp,removal").check(tagged));
 }
 
+TEST_F(CardQuery, FilterTreeTagAttribute)
+{
+    const CardData tagged = taggedCard();
+
+    FilterTree matching;
+    matching.termNode(CardFilter::AttrTag, CardFilter::TypeAnd, "ramp");
+    ASSERT_TRUE(matching.acceptsCard(tagged, CardSearchLanguage{}));
+
+    FilterTree partial;
+    partial.termNode(CardFilter::AttrTag, CardFilter::TypeAnd, "ram");
+    ASSERT_FALSE(partial.acceptsCard(tagged, CardSearchLanguage{}));
+
+    FilterTree missing;
+    missing.termNode(CardFilter::AttrTag, CardFilter::TypeAnd, "squirrel");
+    ASSERT_FALSE(missing.acceptsCard(tagged, CardSearchLanguage{}));
+}
+
 TEST_F(CardQuery, TagQueryFalseWhenCardHasNoTags)
 {
     ASSERT_FALSE(FilterString("tags:ramp").check(cat));