feat: image variants per image

internal/infrastructure/useCases/GenerateImageVariant.go

@@ -0,0 +1,44 @@
+package useCases
+
+import (
+	"RenewCMS/internal/domain/image"
+	"context"
+)
+
+type GenerateImageVariantUseCase struct {
+	images    image.Repository
+	variants  image.VariantRepository
+	files     image.VariantFileRepository
+	renderer  image.VariantRenderer
+	generator *ServeVariantUseCase
+}
+
+func NewGenerateImageVariantUseCase(images image.Repository, variants image.VariantRepository, files image.VariantFileRepository, renderer image.VariantRenderer, generator *ServeVariantUseCase) *GenerateImageVariantUseCase {
+	return &GenerateImageVariantUseCase{images, variants, files, renderer, generator}
+}
+
+func (u *GenerateImageVariantUseCase) Generate(ctx context.Context, id uint32, name string) (ImageVariantView, error) {
+	img, err := u.images.Get(id)
+	if err != nil {
+		return ImageVariantView{}, err
+	}
+	variant, err := u.variants.Get(name)
+	if err != nil {
+		return ImageVariantView{}, err
+	}
+	if !variant.Enabled || variant.Name != name {
+		return ImageVariantView{}, image.ErrVariantNotFound
+	}
+	if isVectorSource(img) {
+		return ImageVariantView{}, image.ErrVariantSourceUnsupported
+	}
+	storedName := image.StoredName(img.Path)
+	if _, err := u.generator.Generate(ctx, variant, storedName); err != nil {
+		return ImageVariantView{}, err
+	}
+	rows, err := currentFiles(u.files, storedName)
+	if err != nil {
+		return ImageVariantView{}, err
+	}
+	return viewOf(variant, img, rows, u.renderer.EncodableFormats()), nil
+}