Added new, focused forecast discussion endpoints for key messages, short term, and long term discussions

internal/adapters/inbound/httpapi/presenter/payload_test.go

@@ -209,6 +209,90 @@ func TestDiscussionPayloadTimezoneConversionAndCopySemantics(t *testing.T) {
 	assertOffsetSeconds(t, run.IssuedAt, 0)
 }
 
+func TestDiscussionFocusedPayloads(t *testing.T) {
+	loc := time.FixedZone("UTC-05:00", -5*60*60)
+	issuedAt := time.Date(2026, 7, 10, 12, 0, 0, 0, time.UTC)
+	updatedAt := issuedAt.Add(30 * time.Minute)
+	shortIssuedAt := issuedAt.Add(-15 * time.Minute)
+	longIssuedAt := issuedAt.Add(15 * time.Minute)
+	run := &model.WeatherForecastDiscussion{
+		OfficeID:    "LSX",
+		OfficeName:  "National Weather Service Saint Louis MO",
+		Product:     model.ForecastDiscussionProductAFD,
+		IssuedAt:    issuedAt,
+		UpdatedAt:   &updatedAt,
+		KeyMessages: nil,
+		ShortTerm:   &model.WeatherForecastDiscussionSection{Qualifier: "(Tonight)", IssuedAt: &shortIssuedAt, Text: "Short term text"},
+		LongTerm:    &model.WeatherForecastDiscussionSection{Qualifier: "(Tomorrow)", IssuedAt: &longIssuedAt, Text: "Long term text"},
+	}
+
+	keyMessagesPayload := DiscussionKeyMessagesOnlyPayload(run, UnitsMetric, loc)
+	keyMessages, ok := keyMessagesPayload.(DiscussionKeyMessagesPayload)
+	if !ok {
+		t.Fatalf("expected DiscussionKeyMessagesPayload, got %T", keyMessagesPayload)
+	}
+	if keyMessages.KeyMessages == nil {
+		t.Fatalf("expected keyMessages slice to be non-nil")
+	}
+	if len(keyMessages.KeyMessages) != 0 {
+		t.Fatalf("expected empty keyMessages slice, got %#v", keyMessages.KeyMessages)
+	}
+	assertOffsetSeconds(t, keyMessages.IssuedAt, -5*60*60)
+	assertOffsetSeconds(t, *keyMessages.UpdatedAt, -5*60*60)
+
+	shortPayload := DiscussionShortTermOnlyPayload(run, UnitsMetric, loc)
+	shortTerm, ok := shortPayload.(DiscussionShortTermPayload)
+	if !ok {
+		t.Fatalf("expected DiscussionShortTermPayload, got %T", shortPayload)
+	}
+	if shortTerm.ShortTerm == nil {
+		t.Fatalf("expected shortTerm section")
+	}
+	if shortTerm.ShortTerm == run.ShortTerm {
+		t.Fatalf("expected shortTerm section copy")
+	}
+	assertOffsetSeconds(t, *shortTerm.ShortTerm.IssuedAt, -5*60*60)
+
+	longPayload := DiscussionLongTermOnlyPayload(run, UnitsMetric, loc)
+	longTerm, ok := longPayload.(DiscussionLongTermPayload)
+	if !ok {
+		t.Fatalf("expected DiscussionLongTermPayload, got %T", longPayload)
+	}
+	if longTerm.LongTerm == nil {
+		t.Fatalf("expected longTerm section")
+	}
+	if longTerm.LongTerm == run.LongTerm {
+		t.Fatalf("expected longTerm section copy")
+	}
+	assertOffsetSeconds(t, *longTerm.LongTerm.IssuedAt, -5*60*60)
+}
+
+func TestDiscussionFocusedPayloadsPreserveNilSections(t *testing.T) {
+	run := &model.WeatherForecastDiscussion{
+		OfficeID: "LSX",
+		Product:  model.ForecastDiscussionProductAFD,
+		IssuedAt: time.Date(2026, 7, 10, 12, 0, 0, 0, time.UTC),
+	}
+
+	shortPayload := DiscussionShortTermOnlyPayload(run, UnitsMetric, nil)
+	shortTerm, ok := shortPayload.(DiscussionShortTermPayload)
+	if !ok {
+		t.Fatalf("expected DiscussionShortTermPayload, got %T", shortPayload)
+	}
+	if shortTerm.ShortTerm != nil {
+		t.Fatalf("expected nil shortTerm, got %+v", shortTerm.ShortTerm)
+	}
+
+	longPayload := DiscussionLongTermOnlyPayload(run, UnitsMetric, nil)
+	longTerm, ok := longPayload.(DiscussionLongTermPayload)
+	if !ok {
+		t.Fatalf("expected DiscussionLongTermPayload, got %T", longPayload)
+	}
+	if longTerm.LongTerm != nil {
+		t.Fatalf("expected nil longTerm, got %+v", longTerm.LongTerm)
+	}
+}
+
 func TestMetricCopyAndNilHandling(t *testing.T) {
 	obs := &model.WeatherObservation{
 		TemperatureC: float64Ptr(20.6),
@@ -239,6 +323,15 @@ func TestMetricCopyAndNilHandling(t *testing.T) {
 	if DiscussionPayload(nil, UnitsUS, nil) != nil {
 		t.Fatalf("expected nil discussion input to return nil payload")
 	}
+	if DiscussionKeyMessagesOnlyPayload(nil, UnitsUS, nil) != nil {
+		t.Fatalf("expected nil key messages discussion input to return nil payload")
+	}
+	if DiscussionShortTermOnlyPayload(nil, UnitsUS, nil) != nil {
+		t.Fatalf("expected nil short term discussion input to return nil payload")
+	}
+	if DiscussionLongTermOnlyPayload(nil, UnitsUS, nil) != nil {
+		t.Fatalf("expected nil long term discussion input to return nil payload")
+	}
 	if CurrentConditionsPayload(nil, UnitsUS, 0) != nil {
 		t.Fatalf("expected nil current conditions input to return nil payload")
 	}