feat: Add PUT and PATCH datasets endpoints

internal/service/dataset.go

@@ -35,6 +35,7 @@ var (
 type DatasetRepository interface {
 	Create(ctx context.Context, d domain.Dataset) (domain.Dataset, error)
 	GetByID(ctx context.Context, id uuid.UUID) (domain.Dataset, error)
+	UpdateFields(ctx context.Context, id, categoryID uuid.UUID, name string, description, unit *string) (domain.Dataset, error)
 	ListSummaries(ctx context.Context, filter domain.DatasetFilter, limit, offset int) ([]domain.DatasetSummary, error)
 	Count(ctx context.Context, filter domain.DatasetFilter) (int, error)
 	Delete(ctx context.Context, id uuid.UUID) error
@@ -183,10 +184,7 @@ func (s *DatasetService) Upload(ctx context.Context, in UploadInput) (domain.Dat
 	}
 	content := io.MultiReader(bytes.NewReader(head), in.Reader)
 
-	if _, err := s.categories.GetByID(ctx, in.CategoryID); err != nil {
-		if errors.Is(err, domain.ErrNotFound) {
-			return domain.Dataset{}, fmt.Errorf("%w: category does not exist", domain.ErrValidation)
-		}
+	if err := s.ensureCategoryExists(ctx, in.CategoryID); err != nil {
 		return domain.Dataset{}, err
 	}
 
@@ -946,6 +944,81 @@ func (s *DatasetService) Get(ctx context.Context, id uuid.UUID) (domain.Dataset,
 	return s.repo.GetByID(ctx, id)
 }
 
+// DatasetUpdateInput carries the full set of editable metadata fields for a
+// PUT replace. Description and Unit being nil clears those (nullable)
+// columns.
+type DatasetUpdateInput struct {
+	CategoryID  uuid.UUID
+	Name        string
+	Description *string
+	Unit        *string
+}
+
+// Update replaces a dataset's editable metadata (category, name, description,
+// unit). File-related and lifecycle fields are untouched.
+func (s *DatasetService) Update(ctx context.Context, id uuid.UUID, in DatasetUpdateInput) (domain.Dataset, error) {
+	if err := s.ensureCategoryExists(ctx, in.CategoryID); err != nil {
+		return domain.Dataset{}, err
+	}
+	return s.repo.UpdateFields(ctx, id, in.CategoryID, in.Name, in.Description, in.Unit)
+}
+
+// DatasetPatchInput carries a sparse set of metadata field changes. A nil
+// CategoryID/Name leaves that column unchanged. Description/Unit are only
+// applied when their paired Set flag is true; a nil value with Set true
+// clears the (nullable) column.
+type DatasetPatchInput struct {
+	CategoryID     *uuid.UUID
+	Name           *string
+	Description    *string
+	DescriptionSet bool
+	Unit           *string
+	UnitSet        bool
+}
+
+// Patch applies a sparse update to a dataset's editable metadata (category,
+// name, description, unit). Fields absent from the input are left unchanged.
+func (s *DatasetService) Patch(ctx context.Context, id uuid.UUID, in DatasetPatchInput) (domain.Dataset, error) {
+	current, err := s.repo.GetByID(ctx, id)
+	if err != nil {
+		return domain.Dataset{}, err
+	}
+
+	categoryID := current.CategoryID
+	if in.CategoryID != nil {
+		categoryID = *in.CategoryID
+		if err := s.ensureCategoryExists(ctx, categoryID); err != nil {
+			return domain.Dataset{}, err
+		}
+	}
+	name := current.Name
+	if in.Name != nil {
+		name = *in.Name
+	}
+	description := current.Description
+	if in.DescriptionSet {
+		description = in.Description
+	}
+	unit := current.Unit
+	if in.UnitSet {
+		unit = in.Unit
+	}
+
+	return s.repo.UpdateFields(ctx, id, categoryID, name, description, unit)
+}
+
+// ensureCategoryExists validates that categoryID references an existing
+// category, mirroring the check performed on upload.
+func (s *DatasetService) ensureCategoryExists(ctx context.Context, categoryID uuid.UUID) error {
+	if _, err := s.categories.GetByID(ctx, categoryID); err != nil {
+		if errors.Is(err, domain.ErrNotFound) {
+			return fmt.Errorf("%w: category does not exist", domain.ErrValidation)
+		}
+		return err
+	}
+	return nil
+}
+
 // Status-wait bounds and polling cadence for long polling.
 const (
 	DefaultStatusWait  = 25 * time.Second