105 lines
2.7 KiB
Go
105 lines
2.7 KiB
Go
package services
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import (
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"bytes"
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"context"
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"fmt"
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"image"
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"image/color"
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"image/draw"
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"image/png"
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"log"
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"slices"
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"time"
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"github.com/boombuler/barcode"
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"github.com/boombuler/barcode/code128"
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"github.com/boombuler/barcode/ean"
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"github.com/boombuler/barcode/qr"
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"github.com/redis/go-redis/v9"
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)
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type BarcodeService interface {
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GenerateBarcode(format string, content string, width int, height int, padding int) (bytes.Buffer, error)
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IsTypeSupported(format string) bool
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}
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type DefaultBarcodeService struct {
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RedisClient *redis.Client
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}
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func (b *DefaultBarcodeService) GenerateBarcode(format string, content string, width int, height int, padding int) (bytes.Buffer, error) {
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ctx := context.Background()
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if !b.IsTypeSupported(format) {
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return bytes.Buffer{}, fmt.Errorf("unsupported barcode type: %s", format)
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}
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if b.RedisClient != nil {
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cachedBarcode, err := b.RedisClient.Get(ctx, fmt.Sprintf("barcode:%s:%s:%d:%d", format, content, width, height)).Result()
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if err == nil {
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log.Printf("Cache hit for barcode:%s:%s:%d:%d", format, content, width, height)
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buf := bytes.Buffer{}
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buf.Write([]byte(cachedBarcode))
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return buf, nil
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}
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}
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var generatedCode barcode.Barcode
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var err error
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switch format {
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case "ean13":
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generatedCode, err = ean.Encode(content)
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if err != nil {
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return bytes.Buffer{}, err
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}
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break
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case "code128":
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generatedCode, err = code128.Encode(content)
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if err != nil {
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return bytes.Buffer{}, err
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}
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break
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case "qr":
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generatedCode, err = qr.Encode(content, qr.M, qr.AlphaNumeric)
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if err != nil {
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return bytes.Buffer{}, err
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}
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break
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}
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scaledCode, err := barcode.Scale(generatedCode, width, height)
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if err != nil {
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return bytes.Buffer{}, err
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}
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// Create a white background image
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bg := image.NewRGBA(image.Rect(0, 0, width+2*padding, height+2*padding))
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white := color.RGBA{255, 255, 255, 255}
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draw.Draw(bg, bg.Bounds(), &image.Uniform{white}, image.Point{}, draw.Src)
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// Draw the barcode on top of the white background with padding
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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)
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var buf bytes.Buffer
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err = png.Encode(&buf, bg)
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if err != nil {
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return bytes.Buffer{}, err
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}
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if b.RedisClient != nil {
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err = b.RedisClient.Set(ctx, fmt.Sprintf("barcode:%s:%s:%d:%d", format, content, width, height), buf.String(), 10*time.Minute).Err()
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if err != nil {
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return bytes.Buffer{}, err
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}
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}
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return buf, nil
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}
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func (b *DefaultBarcodeService) IsTypeSupported(format string) bool {
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supportedTypes := []string{"ean13", "code128", "qr"}
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return slices.Contains(supportedTypes, format)
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}
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