feat(barcode): Padding

services/barcode.go

@@ -4,6 +4,9 @@ import (
 	"bytes"
 	"context"
 	"fmt"
+	"image"
+	"image/color"
+	"image/draw"
 	"image/png"
 	"log"
 	"slices"
@@ -17,7 +20,7 @@ import (
 )
 
 type BarcodeService interface {
-	GenerateBarcode(format string, content string, width int, height int) (bytes.Buffer, error)
+	GenerateBarcode(format string, content string, width int, height int, padding int) (bytes.Buffer, error)
 	IsTypeSupported(format string) bool
 }
 
@@ -25,7 +28,7 @@ type DefaultBarcodeService struct {
 	RedisClient *redis.Client
 }
 
-func (b *DefaultBarcodeService) GenerateBarcode(format string, content string, width int, height int) (bytes.Buffer, error) {
+func (b *DefaultBarcodeService) GenerateBarcode(format string, content string, width int, height int, padding int) (bytes.Buffer, error) {
 	ctx := context.Background()
 
 	if !b.IsTypeSupported(format) {
@@ -71,8 +74,16 @@ func (b *DefaultBarcodeService) GenerateBarcode(format string, content string, w
 		return bytes.Buffer{}, err
 	}
 
+	// Create a white background image
+	bg := image.NewRGBA(image.Rect(0, 0, width+2*padding, height+2*padding))
+	white := color.RGBA{255, 255, 255, 255}
+	draw.Draw(bg, bg.Bounds(), &image.Uniform{white}, image.Point{}, draw.Src)
+
+	// Draw the barcode on top of the white background with padding
+	draw.Draw(bg, scaledCode.Bounds().Add(image.Point{padding + (width-scaledCode.Bounds().Dx())/2, padding + (height-scaledCode.Bounds().Dy())/2}), scaledCode, image.Point{}, draw.Over)
+
 	var buf bytes.Buffer
-	err = png.Encode(&buf, scaledCode)
+	err = png.Encode(&buf, bg)
 	if err != nil {
 		return bytes.Buffer{}, err
 	}

services/templater.go

@@ -42,7 +42,7 @@ func (t *DefaultTemplater) GenerateBarcode(code string, format string, prefix st
 		}
 	}
 
-	buf, err := t.BarcodeService.GenerateBarcode(format, code, 1000, 500)
+	buf, err := t.BarcodeService.GenerateBarcode(format, code, 1000, 500, 0)
 
 	return base64.StdEncoding.EncodeToString(buf.Bytes()), err
 }