From 0929d02b26c2e915ee972162da766a10490342e4 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 26cddd53c..767989925 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_card.cpp
+++ b/libcockatrice_filters/libcockatrice/filters/filter_card.cpp
@@ -87,6 +87,8 @@ 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 dbeffd18f..e5ee9893d 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_card.h
+++ b/libcockatrice_filters/libcockatrice/filters/filter_card.h
@@ -45,6 +45,7 @@ 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 f12f87181..c4006b028 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_tree.cpp
+++ b/libcockatrice_filters/libcockatrice/filters/filter_tree.cpp
@@ -2,6 +2,7 @@
 
 #include "filter_card.h"
 #include "libcockatrice/card/card_localization.h"
+#include "libcockatrice/card/game_specific_terms.h"
 #include "libcockatrice/card/printing/printing_info.h"
 #include "libcockatrice/card/set/card_set.h"
 
@@ -461,6 +462,16 @@ bool FilterItem::acceptFormat(const CardInfoPtr &info) const
     return info->getLegalityProp(lowercaseTerm) == "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
 {
     const QString loyaltyString = info->getLoyalty();
@@ -558,6 +569,8 @@ 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 85a57304d..f97b8bc32 100644
--- a/libcockatrice_filters/libcockatrice/filters/filter_tree.h
+++ b/libcockatrice_filters/libcockatrice/filters/filter_tree.h
@@ -254,6 +254,7 @@ public:
     [[nodiscard]] bool
     acceptCardAttr(const CardInfoPtr &info, CardFilter::Attr attr, const CardSearchLanguage &searchLanguage) const;
     [[nodiscard]] bool acceptFormat(const CardInfoPtr &info) const;
+    [[nodiscard]] bool acceptTag(const 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 37f0a1605..595d56c5f 100644
--- a/tests/carddatabase/filter_string_test.cpp
+++ b/tests/carddatabase/filter_string_test.cpp
@@ -15,6 +15,7 @@
 #include <libcockatrice/card/database/card_database_manager.h>
 #include <libcockatrice/card/printing/printing_info.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>
 #include <string>
@@ -220,6 +221,23 @@ 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));