3 files changed, 67 insertions, 2 deletions
diff --git a/server/internal/api/api.go b/server/internal/api/api.go
index 367a1c6..2db0f91 100644
--- a/server/internal/api/api.go
+++ b/server/internal/api/api.go
@@ -117,6 +117,9 @@ type breakRange struct {
 	// when a break is tapped: it is the only evidence a listener can weigh before deciding
 	// whether the detector got this one right.
 	Partners int `json:"partners,omitempty"`
+	// Origin is which detector found it: "audio", "words", or both. Same reasoning as
+	// Partners -- a listener judging a skip wants to know what decided it.
+	Origin string `json:"origin,omitempty"`
 }
 
 // Handler returns the routed, authenticated handler.
@@ -215,6 +218,7 @@ func (s *Server) episode(w http.ResponseWriter, r *http.Request) {
 			EndMs:    br.EndMs,
 			Kind:     br.Kind,
 			Partners: br.Partners,
+			Origin:   br.Origin,
 		})
 	}
 	writeJSON(w, http.StatusOK, episodeResponse{
diff --git a/server/internal/store/store.go b/server/internal/store/store.go
index b86474d..931cdd3 100644
--- a/server/internal/store/store.go
+++ b/server/internal/store/store.go
@@ -174,8 +174,20 @@ type Break struct {
 	// Kind is "ad" for inserted advertising, or "intro", "cue" or "outro" for the show's own
 	// audio. The phone skips advertising always and furniture by preference.
 	Kind string `json:"kind,omitempty"`
+	// Origin is which detector found it: [FromAudio] or [FromWords]. The listener judging a
+	// skip wants to know why it happened, and the two are not equally sure of themselves --
+	// one compares waveforms across a batch, the other reads what was said.
+	Origin string `json:"origin,omitempty"`
 }
 
+// Where a break came from.
+const (
+	// FromAudio is the cross-correlation scan over several episodes' waveforms.
+	FromAudio = "audio"
+	// FromWords is subtraction or recurrence over the episodes' transcripts.
+	FromWords = "words"
+)
+
 // AllBreaks is every stretch to skip, from both detectors, as one ordered list.
 //
 // Overlapping and touching ranges are merged, because playback seeks to a break's end: two
@@ -187,8 +199,14 @@ type Break struct {
 // other way means sitting through an advertisement the server had already found.
 func (e *Episode) AllBreaks() []Break {
 	all := make([]Break, 0, len(e.Breaks)+len(e.WordBreaks))
-	all = append(all, e.Breaks...)
-	all = append(all, e.WordBreaks...)
+	for _, br := range e.Breaks {
+		br.Origin = FromAudio
+		all = append(all, br)
+	}
+	for _, br := range e.WordBreaks {
+		br.Origin = FromWords
+		all = append(all, br)
+	}
 	sort.Slice(all, func(i, j int) bool { return all[i].StartMs < all[j].StartMs })
 
 	var merged []Break
@@ -203,6 +221,11 @@ func (e *Episode) AllBreaks() []Break {
 			if br.Partners > merged[last].Partners {
 				merged[last].Partners = br.Partners
 			}
+			// Both detectors found it, which is worth saying: they agree by entirely
+			// different means.
+			if br.Origin != merged[last].Origin {
+				merged[last].Origin = FromAudio + "+" + FromWords
+			}
 			continue
 		}
 		merged = append(merged, br)
diff --git a/server/internal/store/store_test.go b/server/internal/store/store_test.go
index c4eafdd..f0c111b 100644
--- a/server/internal/store/store_test.go
+++ b/server/internal/store/store_test.go
@@ -602,3 +602,41 @@ func TestAnEpisodeOfUnknownAgeIsNotRefetched(t *testing.T) {
 		t.Error("would refetch an episode of unknown age")
 	}
 }
+
+/*
+A break says which detector found it.
+
+The listener judging a skip wants to know why it happened, and the two detectors are not equally
+sure of themselves: one compares waveforms across a batch of episodes, the other reads what was
+said. A break both found is worth marking as such -- they agree by entirely different means.
+*/
+
+func TestABreakSaysWhereItCameFrom(t *testing.T) {
+	e := Episode{
+		Breaks:     []Break{{StartMs: 60_000, EndMs: 90_000, Kind: "ad"}},
+		WordBreaks: []Break{{StartMs: 600_000, EndMs: 660_000, Kind: "ad"}},
+	}
+
+	got := e.AllBreaks()
+	if got[0].Origin != FromAudio {
+		t.Errorf("first break says %q, want %q", got[0].Origin, FromAudio)
+	}
+	if got[1].Origin != FromWords {
+		t.Errorf("second break says %q, want %q", got[1].Origin, FromWords)
+	}
+}
+
+func TestABreakBothDetectorsFoundSaysSo(t *testing.T) {
+	e := Episode{
+		Breaks:     []Break{{StartMs: 60_000, EndMs: 90_000, Kind: "ad"}},
+		WordBreaks: []Break{{StartMs: 80_000, EndMs: 120_000, Kind: "ad"}},
+	}
+
+	got := e.AllBreaks()
+	if len(got) != 1 {
+		t.Fatalf("got %+v, want one merged break", got)
+	}
+	if got[0].Origin != FromAudio+"+"+FromWords {
+		t.Errorf("origin = %q, want both named", got[0].Origin)
+	}
+}