initial commit

api/internal/service/helpers.go

@@ -0,0 +1,29 @@
+package service
+
+import (
+	"encoding/json"
+	"fmt"
+	"sort"
+
+	"go-places-api/internal/domain"
+)
+
+// marshalPayload encodes an event payload as JSON.
+func marshalPayload(payload map[string]any) (json.RawMessage, error) {
+	body, err := json.Marshal(payload)
+	if err != nil {
+		return nil, fmt.Errorf("service: marshal event payload: %w", err)
+	}
+	return json.RawMessage(body), nil
+}
+
+// sortRelated orders related places by distance, then by identifier so the
+// result is stable for equal distances.
+func sortRelated(in []domain.RelatedPlace) {
+	sort.SliceStable(in, func(i, j int) bool {
+		if in[i].DistanceMeters != in[j].DistanceMeters {
+			return in[i].DistanceMeters < in[j].DistanceMeters
+		}
+		return in[i].Place.ID < in[j].Place.ID
+	})
+}