Have got adjusting processor arguments working

services/imgedit/processing.go

@@ -21,7 +21,7 @@ type imageProcessor struct {
 
 type shadowProcessorArgs struct {
 	Color   string `json:"color"`
-	OffsetY int    `json:"offset_y"`
+	OffsetY int    `json:"offset_y,string"`
 }
 
 var processors = map[string]imageProcessor{
@@ -35,7 +35,12 @@ var processors = map[string]imageProcessor{
 		processImage: func(ctx context.Context, srcImg image.Image, params any) (image.Image, error) {
 			p := params.(*shadowProcessorArgs)
 
-			shadow := makeBoxShadow(srcImg, color.Black, 4, 10, p.OffsetY)
+			shadowColor, err := parseHexColor(p.Color)
+			if err != nil {
+				return nil, fmt.Errorf("invalid shadow color: %w", err)
+			}
+
+			shadow := makeBoxShadow(srcImg, shadowColor, 4, 10, p.OffsetY)
 			composit := imaging.OverlayCenter(shadow, srcImg, 1.0)
 			return composit, nil
 		},
@@ -135,3 +140,39 @@ type imageImageSource struct {
 func (i imageImageSource) image() (image.Image, error) {
 	return i.img, nil
 }
+
+func parseHexColor(s string) (color.Color, error) {
+	// Remove leading hash if present
+	if len(s) > 0 && s[0] == '#' {
+		s = s[1:]
+	}
+
+	// Parse based on length
+	var r, g, b, a uint8
+	switch len(s) {
+	case 6:
+		// RGB format
+		var rgb uint32
+		if _, err := fmt.Sscanf(s, "%06x", &rgb); err != nil {
+			return nil, fmt.Errorf("invalid hex color format: %w", err)
+		}
+		r = uint8((rgb >> 16) & 0xFF)
+		g = uint8((rgb >> 8) & 0xFF)
+		b = uint8(rgb & 0xFF)
+		a = 0xFF
+	case 8:
+		// RGBA format
+		var rgba uint32
+		if _, err := fmt.Sscanf(s, "%08x", &rgba); err != nil {
+			return nil, fmt.Errorf("invalid hex color format: %w", err)
+		}
+		r = uint8((rgba >> 24) & 0xFF)
+		g = uint8((rgba >> 16) & 0xFF)
+		b = uint8((rgba >> 8) & 0xFF)
+		a = uint8(rgba & 0xFF)
+	default:
+		return nil, fmt.Errorf("invalid hex color length: expected 6 or 8 characters, got %d", len(s))
+	}
+
+	return color.RGBA{R: r, G: g, B: b, A: a}, nil
+}

services/imgedit/service.go

@@ -146,6 +146,35 @@ func (s *Service) DeleteProcessor(ctx context.Context, sessionID, processorID st
 	return session, nil
 }
 
+type UpdateProcessorReq struct {
+	ID    string          `json:"id"`
+	Props json.RawMessage `json:"props"`
+}
+
+func (s *Service) UpdateProcessor(ctx context.Context, sessionID string, req UpdateProcessorReq) (*models.ImageEditSession, error) {
+	session, err := s.loadAndVerifySession(ctx, sessionID)
+	if err != nil {
+		return nil, err
+	}
+
+	for i, p := range session.Processors {
+		if p.ID == req.ID {
+			session.Processors[i].Props = req.Props
+			break
+		}
+	}
+
+	session.RecalcVersionIDs()
+	if err := s.sessionStore.save(session); err != nil {
+		return nil, err
+	}
+	if _, err := s.reprocess(ctx, session); err != nil {
+		return nil, err
+	}
+
+	return session, nil
+}
+
 func (s *Service) loadAndVerifySession(ctx context.Context, sessionID string) (*models.ImageEditSession, error) {
 	site, user, err := s.fetchSiteAndUser(ctx)
 	if err != nil {