copy files from kadai1/tanaka0325

Author: tanaka0325

kadai2/tanaka0325/imgconv/args.go

@@ -0,0 +1,18 @@
+package imgconv
+
+// Args is type for command line arguments.
+type Args []string
+
+func (args Args) uniq() []string {
+	m := map[string]bool{}
+	u := []string{}
+
+	for _, v := range args {
+		if !m[v] {
+			m[v] = true
+			u = append(u, v)
+		}
+	}
+
+	return u
+}

kadai2/tanaka0325/imgconv/cmd/imgconv/main.go

@@ -0,0 +1,30 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+
+	"github.com/gopherdojo/dojo8/kadai2/tanaka0325/imgconv"
+)
+
+var options imgconv.Options
+var args imgconv.Args
+
+func init() {
+	options.From = flag.String("f", "jpg", "file extention before convert")
+	options.To = flag.String("t", "png", "file extention after convert")
+	options.DryRun = flag.Bool("n", false, "dry run")
+	flag.Parse()
+
+	args = flag.Args()
+}
+
+func main() {
+	if err := imgconv.Run(options, args); err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		os.Exit(1)
+	}
+
+	os.Exit(0)
+}

kadai2/tanaka0325/imgconv/conv_image.go

@@ -0,0 +1,82 @@
+package imgconv
+
+import (
+	"fmt"
+	"image"
+	"image/gif"
+	"image/jpeg"
+	"image/png"
+	"io"
+	"os"
+
+	"golang.org/x/image/bmp"
+	"golang.org/x/image/tiff"
+)
+
+// convImage is type included infomation to convert file format.
+type convImage struct {
+	filename string
+	fromExt  string
+	toExt    string
+	image    image.Image
+}
+
+func (i *convImage) decode() error {
+	r, err := os.Open(i.filename + "." + i.fromExt)
+	if err != nil {
+		return err
+	}
+	defer r.Close()
+
+	img, err := decodeHelper(r, i.fromExt)
+	if err != nil {
+		return fmt.Errorf("decode error: %w", err)
+	}
+
+	i.image = img
+	return nil
+}
+
+func decodeHelper(r io.Reader, ext string) (image.Image, error) {
+	switch ext {
+	case "png":
+		return png.Decode(r)
+	case "jpg", "jpeg":
+		return jpeg.Decode(r)
+	case "gif":
+		return gif.Decode(r)
+	case "bmp":
+		return bmp.Decode(r)
+	case "tiff", "tif":
+		return tiff.Decode(r)
+	}
+	return nil, fmt.Errorf("%s is not allowed", ext)
+}
+
+func (i *convImage) encode() error {
+	w, err := os.Create(i.filename + "." + i.toExt)
+	if err != nil {
+		return err
+	}
+	defer func() error {
+		if err := w.Close(); err != nil {
+			return err
+		}
+		return nil
+	}()
+
+	switch i.toExt {
+	case "png":
+		return png.Encode(w, i.image)
+	case "jpg", "jpeg":
+		return jpeg.Encode(w, i.image, nil)
+	case "gif":
+		return gif.Encode(w, i.image, nil)
+	case "bmp":
+		return gif.Encode(w, i.image, nil)
+	case "tiff", "tif":
+		return gif.Encode(w, i.image, nil)
+	}
+
+	return fmt.Errorf("cannot encode image")
+}

kadai2/tanaka0325/imgconv/go.mod

@@ -0,0 +1,5 @@
+module github.com/gopherdojo/dojo8/kadai1/tanaka0325/imgconv
+
+go 1.14
+
+require golang.org/x/image v0.0.0-20200618115811-c13761719519

kadai2/tanaka0325/imgconv/go.mod.back

@@ -0,0 +1,5 @@
+module github.com/gopherdojo/dojo8/kadai1/tanaka0325/imgconv
+
+go 1.14
+
+require golang.org/x/image v0.0.0-20200618115811-c13761719519

kadai2/tanaka0325/imgconv/go.sum

@@ -0,0 +1,3 @@
+golang.org/x/image v0.0.0-20200618115811-c13761719519 h1:1e2ufUJNM3lCHEY5jIgac/7UTjd6cgJNdatjPdFWf34=
+golang.org/x/image v0.0.0-20200618115811-c13761719519/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

kadai2/tanaka0325/imgconv/imgconv.go

@@ -0,0 +1,78 @@
+// Imgconv package is to convert images file format.
+package imgconv
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+var allowedExts = []string{"png", "jpg", "jpeg", "gif", "bmp", "tiff", "tif"}
+
+// Run is to convert image file format
+func Run(options Options, args Args) error {
+	// validator
+	if err := options.validate(allowedExts); err != nil {
+		return err
+	}
+
+	// get target image flepaths from args
+	paths, err := getTargetFilePaths(args, *options.From)
+	if err != nil {
+		return err
+	}
+
+	// convert
+	imgs, err := createConvImages(paths, *options.From, *options.To)
+	if err != nil {
+		return err
+	}
+	for _, img := range imgs {
+		if err := img.decode(); err != nil {
+			return err
+		}
+
+		if *options.DryRun {
+			fmt.Println(img.filename+"."+img.fromExt, "=>", img.filename+"."+img.toExt)
+		} else {
+			if err := img.encode(); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func getTargetFilePaths(args Args, from string) ([]string, error) {
+	uns := args.uniq()
+	paths := []string{}
+
+	for _, n := range uns {
+		if err := filepath.Walk(n, func(path string, info os.FileInfo, err error) error {
+			if filepath.Ext(path) == "."+from {
+				paths = append(paths, path)
+			}
+			return nil
+		}); err != nil {
+			return nil, err
+		}
+	}
+
+	return paths, nil
+}
+
+func createConvImages(paths []string, from, to string) ([]convImage, error) {
+	images := []convImage{}
+	for _, p := range paths {
+		i := convImage{
+			filename: strings.Replace(p, "."+from, "", 1),
+			fromExt:  strings.ToLower(from),
+			toExt:    strings.ToLower(to),
+		}
+		images = append(images, i)
+	}
+
+	return images, nil
+}

kadai2/tanaka0325/imgconv/options.go

@@ -0,0 +1,36 @@
+package imgconv
+
+import (
+	"errors"
+	"fmt"
+	"strings"
+)
+
+// Args is type for command line options.
+type Options struct {
+	From   *string
+	To     *string
+	DryRun *bool
+}
+
+func (opt Options) validate(allow_list []string) error {
+	to := strings.ToLower(*opt.To)
+	from := strings.ToLower(*opt.From)
+	targetExts := []string{to, from}
+	for _, e := range targetExts {
+		if err := include(allow_list, e); err != nil {
+			return fmt.Errorf("%w. ext is only allowd in %s", err, allow_list)
+		}
+	}
+
+	return nil
+}
+
+func include(list []string, w string) error {
+	for _, e := range list {
+		if e == w {
+			return nil
+		}
+	}
+	return errors.New(w + " is not allowed")
+}