docs(swagger): New barcode padding docs

docs/docs.go

@@ -70,6 +70,15 @@ const docTemplate = `{
                         "description": "Barcode height",
                         "name": "height",
                         "in": "query"
+                    },
+                    {
+                        "maximum": 100,
+                        "minimum": 0,
+                        "type": "integer",
+                        "default": 10,
+                        "description": "Padding around the barcode (included in image size)",
+                        "name": "padding",
+                        "in": "query"
                     }
                 ],
                 "responses": {}

docs/swagger.json

@@ -61,6 +61,15 @@
                         "description": "Barcode height",
                         "name": "height",
                         "in": "query"
+                    },
+                    {
+                        "maximum": 100,
+                        "minimum": 0,
+                        "type": "integer",
+                        "default": 10,
+                        "description": "Padding around the barcode (included in image size)",
+                        "name": "padding",
+                        "in": "query"
                     }
                 ],
                 "responses": {}

docs/swagger.yaml

@@ -190,6 +190,13 @@ paths:
         minimum: 1
         name: height
         type: integer
+      - default: 10
+        description: Padding around the barcode (included in image size)
+        in: query
+        maximum: 100
+        minimum: 0
+        name: padding
+        type: integer
       produces:
       - image/png
       responses: {}

handlers/barcode.go

@@ -15,6 +15,7 @@ import (
 //	@Param			content	path	string	true	"Barcode content"										MinLength(1)
 //	@Param			width	query	int		false	"Barcode width"											Minimum(1)	Maximum(10000)	default(1000)
 //	@Param			height	query	int		false	"Barcode height"										Minimum(1)	Maximum(10000)	default(1000)
+//	@Param			padding	query	int		false	"Padding around the barcode (included in image size)"	Minimum(0)	Maximum(100)	default(10)
 //	@Produce		image/png
 //	@Router			/v1/barcodes/{type}/{content} [get]
 func (h *DefaultHandler) GenerateBarcode(c *fiber.Ctx) error {
@@ -26,6 +27,7 @@ func (h *DefaultHandler) GenerateBarcode(c *fiber.Ctx) error {
 	// Get the width and height from the query parameters
 	widthStr := c.Query("width", "1000")
 	heightStr := c.Query("height", "1000")
+	paddingStr := c.Query("padding", "10")
 
 	// Convert width and height to integers
 	width, err := strconv.Atoi(widthStr)
@@ -42,8 +44,15 @@ func (h *DefaultHandler) GenerateBarcode(c *fiber.Ctx) error {
 		})
 	}
 
+	padding, err := strconv.Atoi(paddingStr)
+	if err != nil {
+		return c.Status(fiber.StatusBadRequest).JSON(fiber.Map{
+			"error": "Invalid padding parameter",
+		})
+	}
+
 	// Generate the barcode
-	barcode, err := h.BarcodeService.GenerateBarcode(barcodeType, barcodeContent, width, height)
+	barcode, err := h.BarcodeService.GenerateBarcode(barcodeType, barcodeContent, width, height, padding)
 	if err != nil {
 		return c.Status(fiber.StatusInternalServerError).JSON(fiber.Map{
 			"error": err.Error(),

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) {
@@ -33,7 +36,7 @@ func (b *DefaultBarcodeService) GenerateBarcode(format string, content string, w
 	}
 
 	if b.RedisClient != nil {
-		cachedBarcode, err := b.RedisClient.Get(ctx, fmt.Sprintf("barcode:%s:%s:%d:%d", format, content, width, height)).Result()
+		cachedBarcode, err := b.RedisClient.Get(ctx, fmt.Sprintf("barcode:%s:%s:%d:%d:%d", format, content, width, height, padding)).Result()
 		if err == nil {
 			log.Printf("Cache hit for barcode:%s:%s:%d:%d", format, content, width, height)
 			buf := bytes.Buffer{}
@@ -66,13 +69,26 @@ func (b *DefaultBarcodeService) GenerateBarcode(format string, content string, w
 		break
 	}
 
-	scaledCode, err := barcode.Scale(generatedCode, width, height)
+	// Create a white background image
+	bg := image.NewRGBA(image.Rect(0, 0, width, height))
+	white := color.RGBA{255, 255, 255, 255}
+	draw.Draw(bg, bg.Bounds(), &image.Uniform{white}, image.Point{}, draw.Src)
+
+	// Calculate the new size for the barcode to fit within the padding
+	newWidth := width - 2*padding
+	newHeight := height - 2*padding
+
+	// Scale the barcode to the new size
+	scaledCode, err := barcode.Scale(generatedCode, newWidth, newHeight)
 	if err != nil {
 		return bytes.Buffer{}, err
 	}
 
+	// Draw the barcode on top of the white background with padding
+	draw.Draw(bg, scaledCode.Bounds().Add(image.Point{padding, padding}), 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
 }