From 710c53b4b4f0e3db553e239f771dc87d542aac41 Mon Sep 17 00:00:00 2001
From: emeric <emeric.poupon@laposte.net>
Date: Fri, 5 Jun 2026 13:53:30 +0200
Subject: [PATCH] Try not to suggest same audio tracks, added some unit tests

---
 .../NearDuplicateEmbeddingConstraint.hpp      |  2 +-
 .../recommendation/test/CMakeLists.txt        |  1 +
 .../recommendation/test/ConstraintsTest.cpp   | 74 +++++++++++++++++++
 3 files changed, 76 insertions(+), 1 deletion(-)

diff --git a/src/libs/services/recommendation/impl/audio-similarity/NearDuplicateEmbeddingConstraint.hpp b/src/libs/services/recommendation/impl/audio-similarity/NearDuplicateEmbeddingConstraint.hpp
index 4f1e6a56..8cf49725 100644
--- a/src/libs/services/recommendation/impl/audio-similarity/NearDuplicateEmbeddingConstraint.hpp
+++ b/src/libs/services/recommendation/impl/audio-similarity/NearDuplicateEmbeddingConstraint.hpp
@@ -25,8 +25,8 @@
 #include "math/NormalizedCosineDistance.hpp"
 #include "math/Vector.hpp"
 
-#include "track-selection-constraints/ITrackCandidateHardConstraint.hpp"
 #include "Types.hpp"
+#include "track-selection-constraints/ITrackCandidateHardConstraint.hpp"
 
 namespace lms::recommendation
 {
diff --git a/src/libs/services/recommendation/test/CMakeLists.txt b/src/libs/services/recommendation/test/CMakeLists.txt
index 1c748704..34812aed 100644
--- a/src/libs/services/recommendation/test/CMakeLists.txt
+++ b/src/libs/services/recommendation/test/CMakeLists.txt
@@ -4,6 +4,7 @@ add_executable(test-recommendation
 
 target_link_libraries(test-recommendation PRIVATE
 	lmsrecommendation
+	lmsmath
 	GTest::GTest
 	GTest::gtest_main
 	)
diff --git a/src/libs/services/recommendation/test/ConstraintsTest.cpp b/src/libs/services/recommendation/test/ConstraintsTest.cpp
index ebc4e25e..5fe8dd29 100644
--- a/src/libs/services/recommendation/test/ConstraintsTest.cpp
+++ b/src/libs/services/recommendation/test/ConstraintsTest.cpp
@@ -22,7 +22,9 @@
 #include "database/objects/ArtistId.hpp"
 #include "database/objects/ReleaseId.hpp"
 #include "database/objects/TrackId.hpp"
+#include "math/Vector.hpp"
 
+#include "audio-similarity/NearDuplicateEmbeddingConstraint.hpp"
 #include "track-selection-constraints/DuplicateTrackConstraint.hpp"
 #include "track-selection-constraints/SameArtistConstraint.hpp"
 #include "track-selection-constraints/SameReleaseConstraint.hpp"
@@ -238,3 +240,75 @@ TEST(TrackCandidateEvaluator, hardConstraintPassesEvenWithSoftConstraints)
     EXPECT_FALSE(evaluator.rejects(ctx));
     EXPECT_FLOAT_EQ(evaluator.score(ctx), 1.F);
 }
+
+namespace
+{
+    using TestVec = math::Vector<2, float>;
+    const TestVec v_x{ 1.F, 0.F };
+    const TestVec v_y{ 0.F, 1.F };
+
+    using TestConstraint = NearDuplicateEmbeddingConstraint<2>;
+    using TestVectorMap = TestConstraint::TrackVectorMap;
+} // namespace
+
+TEST(NearDuplicateEmbeddingConstraint, acceptsWhenCandidateNotInMap)
+{
+    const TestVectorMap trackVectors{ { T1, &v_x } };
+    const TestConstraint constraint{ trackVectors, 0.1F };
+    const std::vector<db::TrackId> selected{ T1 };
+    const TrackCandidateContext ctx{ .candidateTrackId = T2, .selectedTracks = selected };
+    EXPECT_FALSE(constraint.rejects(ctx));
+}
+
+TEST(NearDuplicateEmbeddingConstraint, acceptsWhenSelectionEmpty)
+{
+    const TestVectorMap trackVectors{ { T1, &v_x } };
+    const TestConstraint constraint{ trackVectors, 0.1F };
+    const TrackCandidateContext ctx{ .candidateTrackId = T1, .selectedTracks = {} };
+    EXPECT_FALSE(constraint.rejects(ctx));
+}
+
+TEST(NearDuplicateEmbeddingConstraint, acceptsWhenSelectedTrackNotInMap)
+{
+    const TestVectorMap trackVectors{ { T1, &v_x } };
+    const TestConstraint constraint{ trackVectors, 0.1F };
+    const std::vector<db::TrackId> selected{ T2 };
+    const TrackCandidateContext ctx{ .candidateTrackId = T1, .selectedTracks = selected };
+    EXPECT_FALSE(constraint.rejects(ctx));
+}
+
+TEST(NearDuplicateEmbeddingConstraint, rejectsWhenDistanceBelowThreshold)
+{
+    const TestVectorMap trackVectors{ { T1, &v_x }, { T2, &v_x } };
+    const TestConstraint constraint{ trackVectors, 0.1F };
+    const std::vector<db::TrackId> selected{ T2 };
+    const TrackCandidateContext ctx{ .candidateTrackId = T1, .selectedTracks = selected };
+    EXPECT_TRUE(constraint.rejects(ctx));
+}
+
+TEST(NearDuplicateEmbeddingConstraint, acceptsWhenDistanceAboveThreshold)
+{
+    const TestVectorMap trackVectors{ { T1, &v_x }, { T2, &v_y } };
+    const TestConstraint constraint{ trackVectors, 0.1F };
+    const std::vector<db::TrackId> selected{ T2 };
+    const TrackCandidateContext ctx{ .candidateTrackId = T1, .selectedTracks = selected };
+    EXPECT_FALSE(constraint.rejects(ctx));
+}
+
+TEST(NearDuplicateEmbeddingConstraint, rejectsWhenOneOfManySelectedIsNearDuplicate)
+{
+    const TestVectorMap trackVectors{ { T1, &v_x }, { T3, &v_y }, { T4, &v_x } };
+    const TestConstraint constraint{ trackVectors, 0.1F };
+    const std::vector<db::TrackId> selected{ T3, T4 };
+    const TrackCandidateContext ctx{ .candidateTrackId = T1, .selectedTracks = selected };
+    EXPECT_TRUE(constraint.rejects(ctx));
+}
+
+TEST(NearDuplicateEmbeddingConstraint, acceptsWhenAllSelectedAreFarEnough)
+{
+    const TestVectorMap trackVectors{ { T1, &v_x }, { T2, &v_y }, { T3, &v_y } };
+    const TestConstraint constraint{ trackVectors, 0.1F };
+    const std::vector<db::TrackId> selected{ T2, T3 };
+    const TrackCandidateContext ctx{ .candidateTrackId = T1, .selectedTracks = selected };
+    EXPECT_FALSE(constraint.rejects(ctx));
+}