preserve orientation

1 files changed, 54 insertions, 15 deletions

diff --git a/cmd/server/main.go b/cmd/server/main.go
index f0f7637..41dbce0 100644
--- a/cmd/server/main.go
+++ b/cmd/server/main.go
@@ -8,6 +8,7 @@ import (
 	"crypto/sha256"
 	"encoding/base64"
 	"encoding/hex"
+	"encoding/json"
 	"errors"
 	"flag"
 	"fmt"
@@ -113,6 +114,11 @@ const (
 
 const maxUpload = 100 * MiB
 
+type exifTag struct {
+	SourceFile  string
+	Orientation string
+}
+
 func upload(b *storage.BucketHandle) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if r.Method != http.MethodPost {
@@ -168,25 +174,18 @@ func upload(b *storage.BucketHandle) http.Handler {
 		tmp.Close()
 		file.Close()
 		r.MultipartForm.RemoveAll()
-		cmd := exec.Command("exiftool", "-all=", "--icc_profile:all", "-overwrite_original_in_place", tmp.Name())
-		var stdOutErr bytes.Buffer
-		cmd.Stdout = &stdOutErr
-		cmd.Stderr = &stdOutErr
-		if err := cmd.Start(); err != nil {
-			log.Printf("cmd.Start() = %v", err)
-			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-			return
+		or, err := orientation(r.Context(), tmp.Name())
+		if err != nil {
+			log.Printf("orientation(%q) = %v, %v", tmp.Name(), or, err)
 		}
-		if err := WaitOrStop(r.Context(), cmd, os.Kill, 100*time.Millisecond); err != nil {
-			log.Printf("WaitOrStop(_, %v, %s) = %v", cmd, 100*time.Millisecond, err)
-			log.Printf("Output: %s", stdOutErr.String())
+		out, err := commandContext(r.Context(), "exiftool", "-all=", "--icc_profile:all", "-overwrite_original_in_place", tmp.Name())
+		if err != nil {
+			log.Printf("commandContext(): %v, %q", err, string(out))
 			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
 			return
 		}
-		if code := cmd.ProcessState.ExitCode(); code != 0 {
-			log.Printf("cmd.ProcessState.ExitCode() = %d", code)
-			http.Error(w, http.StatusText(http.StatusInternalServerError), http.StatusInternalServerError)
-			return
+		if err := setOrientation(r.Context(), tmp.Name(), or); err != nil {
+			log.Printf("setOrientation(%q) = %v", tmp.Name(), err)
 		}
 
 		ct := head.Header.Get("content-type")
@@ -220,6 +219,46 @@ func upload(b *storage.BucketHandle) http.Handler {
 	})
 }
 
+func commandContext(ctx context.Context, name string, arg ...string) ([]byte, error) {
+	cmd := exec.Command(name, arg...)
+	var stdOutErr bytes.Buffer
+	cmd.Stdout = &stdOutErr
+	cmd.Stderr = &stdOutErr
+	if err := cmd.Start(); err != nil {
+		return stdOutErr.Bytes(), fmt.Errorf("cmd.Start() = %w", err)
+	}
+	if err := WaitOrStop(ctx, cmd, os.Kill, 100*time.Millisecond); err != nil {
+		return stdOutErr.Bytes(), fmt.Errorf("WaitOrStop(_, %v, %s) = %w", cmd, 100*time.Millisecond, err)
+	}
+	if code := cmd.ProcessState.ExitCode(); code != 0 {
+		return stdOutErr.Bytes(), fmt.Errorf("cmd.ProcessState.ExitCode() = %d", code)
+	}
+	return stdOutErr.Bytes(), nil
+}
+
+func orientation(ctx context.Context, filename string) (string, error) {
+	o, err := commandContext(ctx, "exiftool", "-j", "-Orientation", filename)
+	if err != nil {
+		return "", err
+	}
+	var tags []exifTag
+	if err := json.Unmarshal(o, &tags); err != nil || len(tags) == 0 {
+		return "", err
+	}
+	log.Println(tags)
+	return tags[0].Orientation, nil
+}
+
+func setOrientation(ctx context.Context, filename string, or string) error {
+	args := []string{fmt.Sprintf("-Orientation=%s", or), "-overwrite_original_in_place", filename}
+	out, err := commandContext(ctx, "exiftool", args...)
+	if err != nil {
+		log.Printf("setOrientation: %v, %+v, %q", err, args, out)
+		return err
+	}
+	return nil
+}
+
 func filename() string {
 	b := make([]byte, 8)
 	n, err := rand.Read(b)