first commit

.gitignore

@@ -0,0 +1,3 @@
+image-resize
+results.csv
+out

go.mod

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+module bitbucket.org/tekion/image-resize
+
+go 1.18
+
+require github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 // indirect

go.sum

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+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646 h1:zYyBkD/k9seD2A7fsi6Oo2LfFZAehjjQMERAvZLEDnQ=
+github.com/nfnt/resize v0.0.0-20180221191011-83c6a9932646/go.mod h1:jpp1/29i3P1S/RLdc7JQKbRpFeM1dOBd8T9ki5s+AY8=

main.go

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+package main
+
+import (
+	"encoding/csv"
+	"fmt"
+	"github.com/nfnt/resize"
+	"image"
+	"image/jpeg"
+	"image/png"
+	"io"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"path/filepath"
+	"strconv"
+)
+
+var finalWidth uint = 1920
+var outPath = filepath.Join(".", "out")
+var inputPath = filepath.Join(".", "assets")
+
+func readArgs() {
+	fmt.Println(len(os.Args), os.Args)
+	if len(os.Args) == 4 {
+		inputPath = os.Args[1]
+		outPath = os.Args[2]
+		i, _ := strconv.Atoi(os.Args[3])
+		if i <= 0 {
+			fmt.Println("Wrong input for resolution, arguments: <source_dir> <dest_dir> <width_resolution_px>")
+			os.Exit(1)
+		}
+	}
+}
+
+func main() {
+	fmt.Println("arguments: <source_dir> <dest_dir> <width_resolution_px>")
+	readArgs()
+
+	err := os.MkdirAll(outPath, os.ModePerm)
+	if err != nil {
+		fmt.Println("unable to create path", err)
+		return
+	}
+	results := [][]string{
+		{"File name", "success", "resized", "old resolution", "new resolution"},
+	}
+
+	allFilePath := listFiles(inputPath)
+
+	for _, filePath := range allFilePath {
+		handleFile(filePath, &results)
+	}
+	fmt.Println("results:", results)
+
+	writeResult(results)
+}
+func handleFile(filePath string, results *[][]string) {
+	var individualResult = map[string]string{"fileName": filepath.Base(filePath), "success": "no", "resized": "no", "old": ""}
+	file, err := os.Open(filePath)
+	if err != nil {
+		individualResult["success"] = "no"
+		individualResult["resized"] = "no"
+		fmt.Println("unable to open file", err)
+		updateResult(results, individualResult)
+		return
+	}
+	var img image.Image
+	isImage := false
+	fileType := readFileType(filePath)
+	switch fileType {
+	case "image/jpeg":
+		img, err = jpeg.Decode(file)
+		if err != nil {
+			individualResult["success"] = "no"
+			individualResult["resized"] = "no"
+			fmt.Println("unable to decode jpeg", err)
+			updateResult(results, individualResult)
+			return
+		}
+		isImage = true
+
+	case "image/png":
+		img, err = png.Decode(file)
+		if err != nil {
+			individualResult["success"] = "no"
+			individualResult["resized"] = "no"
+			fmt.Println("unable to decode png", err)
+			updateResult(results, individualResult)
+			return
+		}
+		isImage = true
+	}
+
+	if isImage {
+		resizeImage(filePath, file, img, individualResult)
+	} else {
+		individualResult["success"] = "no"
+		individualResult["resized"] = "no"
+	}
+	defer func() {
+		updateResult(results, individualResult)
+		file.Close()
+	}()
+}
+func updateResult(results *[][]string, individualResult map[string]string) {
+	*results = append(*results, []string{individualResult["fileName"], individualResult["success"], individualResult["resized"], individualResult["old"], individualResult["new"]})
+}
+
+func resizeImage(filePath string, file *os.File, img image.Image, individualResult map[string]string) {
+	fileName := filepath.Base(file.Name())
+	outFileName := outPath + "/" + fileName
+	individualResult["old"] = strconv.Itoa(img.Bounds().Dx()) + " x " + strconv.Itoa(img.Bounds().Dy())
+
+	if uint(img.Bounds().Dx()) <= finalWidth {
+		fmt.Println("ignoring as the resolution is less, file:", filepath.Base(filePath))
+		individualResult["resized"] = "no"
+		individualResult["success"] = "yes"
+		_, err := copy(filePath, outFileName)
+		if err != nil {
+			individualResult["success"] = "no"
+			individualResult["resized"] = "no"
+			fmt.Println("Error while copying file", err)
+			return
+		}
+		return
+	}
+
+	m := resize.Resize(finalWidth, 0, img, resize.Lanczos3)
+	individualResult["new"] = strconv.Itoa(m.Bounds().Dx()) + " x " + strconv.Itoa(m.Bounds().Dy())
+	out, err := os.Create(outFileName)
+	if err != nil {
+		individualResult["success"] = "no"
+		individualResult["resized"] = "no"
+		fmt.Println("unable to create image", err)
+		return
+	}
+	// write new image to file
+	err = jpeg.Encode(out, m, nil)
+	if err != nil {
+		individualResult["success"] = "no"
+		individualResult["resized"] = "no"
+		fmt.Println("unable to write image", err)
+		return
+	}
+	individualResult["success"] = "yes"
+	individualResult["resized"] = "yes"
+
+	defer out.Close()
+}
+
+func listFiles(path string) []string {
+	var allFilePath []string
+
+	entries, err := os.ReadDir(path)
+	if err != nil {
+		fmt.Println("unable to read dir", err)
+	}
+
+	for _, e := range entries {
+		allFilePath = append(allFilePath, filepath.Join(".", path, e.Name()))
+	}
+	return allFilePath
+
+}
+
+func readFileType(path string) string {
+	contents, _ := ioutil.ReadFile(path)
+	return http.DetectContentType(contents)
+}
+
+func copy(src, dst string) (int64, error) {
+	sourceFileStat, err := os.Stat(src)
+	if err != nil {
+		return 0, err
+	}
+
+	if !sourceFileStat.Mode().IsRegular() {
+		return 0, fmt.Errorf("%s is not a regular file", src)
+	}
+
+	source, err := os.Open(src)
+	if err != nil {
+		return 0, err
+	}
+	defer source.Close()
+
+	destination, err := os.Create(dst)
+	if err != nil {
+		return 0, err
+	}
+	defer destination.Close()
+	nBytes, err := io.Copy(destination, source)
+	return nBytes, err
+}
+
+func writeResult(results [][]string) {
+	f, err := os.Create("results.csv")
+	defer f.Close()
+	if err != nil {
+		fmt.Println("writeResult: failed to open file", err)
+		return
+	}
+
+	w := csv.NewWriter(f)
+	w.WriteAll(results)
+}