refactor(go): make daily metric totals opt in

go/vehicle-gateway/internal/stats/query.go

@@ -17,12 +17,13 @@ type Queryer interface {
 }
 
 type MetricQuery struct {
-	VIN      string
-	Protocol string
-	DateFrom string
-	DateTo   string
-	Limit    int
-	Offset   int
+	VIN          string
+	Protocol     string
+	IncludeTotal bool
+	DateFrom     string
+	DateTo       string
+	Limit        int
+	Offset       int
 }
 
 type MetricRow struct {
@@ -184,16 +185,22 @@ func (h *MetricHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		writeMetricError(w, http.StatusBadRequest, err.Error())
 		return
 	}
-	total, err := h.repository.Count(r.Context(), query)
-	if err != nil {
-		writeMetricError(w, http.StatusInternalServerError, err.Error())
-		return
+	var total int64
+	if query.IncludeTotal {
+		total, err = h.repository.Count(r.Context(), query)
+		if err != nil {
+			writeMetricError(w, http.StatusInternalServerError, err.Error())
+			return
+		}
 	}
 	rows, err := h.repository.Query(r.Context(), query)
 	if err != nil {
 		writeMetricError(w, http.StatusInternalServerError, err.Error())
 		return
 	}
+	if !query.IncludeTotal {
+		total = int64(len(rows))
+	}
 	w.Header().Set("Content-Type", "application/json")
 	_ = json.NewEncoder(w).Encode(map[string]any{
 		"items":  rows,
@@ -214,12 +221,13 @@ func parseMetricQuery(r *http.Request) (MetricQuery, error) {
 		return MetricQuery{}, err
 	}
 	query := MetricQuery{
-		VIN:      values.Get("vin"),
-		Protocol: values.Get("protocol"),
-		DateFrom: values.Get("dateFrom"),
-		DateTo:   values.Get("dateTo"),
-		Limit:    limit,
-		Offset:   offset,
+		VIN:          values.Get("vin"),
+		Protocol:     values.Get("protocol"),
+		IncludeTotal: strings.EqualFold(strings.TrimSpace(values.Get("includeTotal")), "true"),
+		DateFrom:     values.Get("dateFrom"),
+		DateTo:       values.Get("dateTo"),
+		Limit:        limit,
+		Offset:       offset,
 	}
 	if !validDate(query.DateFrom) || !validDate(query.DateTo) {
 		return MetricQuery{}, errors.New("dateFrom/dateTo must use YYYY-MM-DD")