Move test data cmd folder

Author: Levko Burburas

pqsignature/cmd/pqsignatures/fingerprint

@@ -1 +1,93 @@
 package pqsignature
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"image/png"
+	"os"
+	"path/filepath"
+
+	"github.com/fogleman/gg"
+	"github.com/makiuchi-d/gozxing"
+	"github.com/makiuchi-d/gozxing/qrcode"
+)
+
+// Encode splits input msg into chunks to fit max supported length of QR code message and generates an array of QR codes images.
+func Encode(msg string, alias string, outputDir string, outputFileTitle string, outputFileNamePattern string, outputFileNameSuffix string) ([]Image, error) {
+	if _, err := os.Stat(outputDir); os.IsNotExist(err) {
+		if err := os.MkdirAll(outputDir, 0770); err != nil {
+			return nil, errors.New(err)
+		}
+	}
+	pngs, err := toPngs(msg, MaxMsgLength, DataQRImageSize)
+	if err != nil {
+		return nil, err
+	}
+	var images []Image
+	for i, imageBytes := range pngs {
+		filePathPartNumber := ""
+		titlePartNumber := ""
+		if len(pngs) > 1 {
+			filePathPartNumber = fmt.Sprintf("__part_%v_of_%v", i+1, len(pngs))
+			titlePartNumber = fmt.Sprintf(" part %v of %v", i+1, len(pngs))
+		}
+		partTitle := fmt.Sprintf("%v%v", outputFileTitle, titlePartNumber)
+		filePath := filepath.Join(outputDir, fmt.Sprintf("%v%v%v.png", outputFileNamePattern, filePathPartNumber, outputFileNameSuffix))
+		err := os.WriteFile(filePath, imageBytes, 0644)
+		if err != nil {
+			return nil, errors.New(err)
+		}
+		img, err := gg.LoadImage(filePath)
+		if err != nil {
+			return nil, errors.New(err)
+		}
+		images = append(images, Image{
+			raw:   imageBytes,
+			title: partTitle,
+			image: img,
+			alias: alias,
+		})
+	}
+	return images, nil
+}
+
+func toPngs(s string, dataSize int, qrImageSize int) ([][]byte, error) {
+	chunks := breakStringIntoChunks(s, dataSize)
+	var qrs [][]byte
+	for _, chunk := range chunks {
+		enc := qrcode.NewQRCodeWriter()
+		image, err := enc.Encode(chunk, gozxing.BarcodeFormat_QR_CODE, qrImageSize, qrImageSize, nil)
+		if err != nil {
+			return nil, errors.New(err)
+		}
+		pngBuffer := new(bytes.Buffer)
+		err = png.Encode(pngBuffer, image)
+		if err != nil {
+			return nil, errors.New(err)
+		}
+		qrs = append(qrs, pngBuffer.Bytes())
+	}
+	return qrs, nil
+}
+
+func breakStringIntoChunks(str string, size int) []string {
+	if len(str) <= size {
+		return []string{str}
+	}
+	var result []string
+	chunk := make([]rune, size)
+	pos := 0
+	for _, rune := range str {
+		chunk[pos] = rune
+		pos++
+		if pos == size {
+			pos = 0
+			result = append(result, string(chunk))
+		}
+	}
+	if pos > 0 {
+		result = append(result, string(chunk[:pos]))
+	}
+	return result
+}