feat: image variants engine

internal/infrastructure/useCases/ListVariants.go

@@ -0,0 +1,28 @@
+package useCases
+
+import "RenewCMS/internal/domain/image"
+
+type ListVariantsUseCase struct {
+	variants image.VariantRepository
+	files    image.VariantFileRepository
+}
+
+func NewListVariantsUseCase(variants image.VariantRepository, files image.VariantFileRepository) *ListVariantsUseCase {
+	return &ListVariantsUseCase{variants, files}
+}
+
+func (u *ListVariantsUseCase) List() ([]VariantSummary, error) {
+	variants, err := u.variants.List()
+	if err != nil {
+		return nil, err
+	}
+	totals, err := u.files.Totals()
+	if err != nil {
+		return nil, err
+	}
+	summaries := make([]VariantSummary, 0, len(variants))
+	for _, variant := range variants {
+		summaries = append(summaries, summarize(variant, totals))
+	}
+	return summaries, nil
+}