From ba95e927fed6de327b70fd136a73721a778267e3 Mon Sep 17 00:00:00 2001
From: Gregory Eremin <g@erem.in>
Date: Sat, 8 Jun 2019 14:15:12 +0200
Subject: [PATCH] Initial commit

---
 main.go      | 158 +++++++++++++++++++++++++++++++++++++++++++++++++++
 main_test.go |  17 ++++++
 2 files changed, 175 insertions(+)
 create mode 100644 main.go
 create mode 100644 main_test.go

diff --git a/main.go b/main.go
new file mode 100644
index 0000000..23c87e7
--- /dev/null
+++ b/main.go
@@ -0,0 +1,158 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/rwcarlsen/goexif/exif"
+)
+
+type processFn func(path, format string) error
+
+var counters = make(map[string]int)
+
+func main() {
+	srcDir := flag.String("in", ".", "Source directory")
+	format := flag.String("out", "dist/%Y/%m/%d-%H%M%S",
+		"Output format (use strftime symbols %Y, %y, %m, %d, %H, %M, %S)",
+	)
+	dryRun := flag.Bool("dryrun", false, "Dry run")
+	flag.Parse()
+
+	formatNorm := toTimeFormat(*format)
+	var fn processFn
+	n := -1
+	if *dryRun {
+		fmt.Println("Dry run. Examples of moved files:")
+		fn = previewFile
+		n = 10
+	} else {
+		fn = processFile
+	}
+	if err := processDir(*srcDir, formatNorm, n, fn); err != nil {
+		log.Println(err)
+	}
+}
+
+func processDir(dir, format string, max int, fn processFn) error {
+	var i int
+	return filepath.Walk(dir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+		if i < 0 || i > max {
+			return filepath.SkipDir
+		}
+		if !info.IsDir() {
+			i++
+			return fn(path, format)
+		}
+		return nil
+	})
+}
+
+func processFile(path, format string) error {
+	if ext := strings.ToLower(filepath.Ext(path)); !isSupportedExt(ext) {
+		return nil
+	}
+
+	src, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer src.Close()
+
+	ts, err := getDate(src)
+	if err != nil {
+		return err
+	}
+
+	newPath := ts.Format(format) + "-" + strconv.Itoa(nextIndex(ts)) + ".jpg"
+	dir := filepath.Dir(newPath)
+	if err := os.MkdirAll(dir, 0755); err != nil {
+		return err
+	}
+
+	dest, err := os.Create(newPath)
+	if err != nil {
+		return err
+	}
+	defer dest.Close()
+
+	if _, err := io.Copy(dest, src); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func previewFile(path, format string) error {
+	if ext := strings.ToLower(filepath.Ext(path)); !isSupportedExt(ext) {
+		return nil
+	}
+
+	src, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer src.Close()
+
+	ts, err := getDate(src)
+	if err != nil {
+		return err
+	}
+
+	newPath := ts.Format(format) + "-" + strconv.Itoa(nextIndex(ts)) + ".jpg"
+	fmt.Printf("%s -> %s\n", path, newPath)
+
+	return nil
+}
+
+func isSupportedExt(ext string) bool {
+	switch ext {
+	case ".jpg":
+		return true
+	default:
+		return false
+	}
+}
+
+func getDate(fd io.ReadSeeker) (time.Time, error) {
+	ef, err := exif.Decode(fd)
+	if err != nil {
+		return time.Time{}, err
+	}
+
+	_, err = fd.Seek(0, 0)
+	if err != nil {
+		return time.Time{}, err
+	}
+
+	return ef.DateTime()
+}
+
+func nextIndex(ts time.Time) int {
+	key := ts.Format("20060102150405")
+	counters[key]++
+	return counters[key]
+}
+
+func toTimeFormat(f string) string {
+	f = strings.Replace(f, "%y", "2006", -1)
+	f = strings.Replace(f, "%Y", "06", -1)
+	f = strings.Replace(f, "%m", "01", -1)
+	f = strings.Replace(f, "%d", "02", -1)
+
+	f = strings.Replace(f, "%H", "15", -1)
+	f = strings.Replace(f, "%M", "04", -1)
+	f = strings.Replace(f, "%S", "05", -1)
+
+	return f
+}
diff --git a/main_test.go b/main_test.go
new file mode 100644
index 0000000..a916df3
--- /dev/null
+++ b/main_test.go
@@ -0,0 +1,17 @@
+package main
+
+import (
+	"testing"
+)
+
+func TestToTimeFormat(t *testing.T) {
+	assertEqualStr(t, "dist/photos/06/01/02-150405", toTimeFormat("dist/photos/%Y/%m/%d-%H%M%S"))
+	assertEqualStr(t, "dist/2006-01-02/150405", toTimeFormat("dist/%y-%m-%d/%H%M%S"))
+}
+
+func assertEqualStr(t *testing.T, exp, out string) {
+	t.Helper()
+	if exp != out {
+		t.Errorf("Expected %q, got %q", exp, out)
+	}
+}
\ No newline at end of file