From 1d80c377229b9f3b23e7a1c49ff752e541c692d8 Mon Sep 17 00:00:00 2001
From: PhatPhuckDave <david.majdandzic@hotmail.com>
Date: Sun, 11 Aug 2024 23:50:23 +0200
Subject: [PATCH] Initial commit

---
 go.mod  |   3 ++
 main.go | 120 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 123 insertions(+)
 create mode 100644 go.mod
 create mode 100644 main.go

diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..9a9693e
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module main
+
+go 1.22.4
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..7f7c572
--- /dev/null
+++ b/main.go
@@ -0,0 +1,120 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"log"
+	"os"
+	"regexp"
+	"sync"
+	"sync/atomic"
+)
+
+func init() {
+	log.SetFlags(log.Lmicroseconds)
+}
+
+func main() {
+	padSize := flag.Int("n", 5, "Pad size for new file names")
+	recreate := flag.Bool("f", false, "First rename all files to <name>.bak and then rename them to iter (to prevent conflicts of already existing files)")
+	flag.Parse()
+	nameFormat := fmt.Sprintf("%%0%dd", *padSize)
+
+	originalExtensions := make(map[string]string)
+	var mapMutex sync.RWMutex
+	var wg sync.WaitGroup
+	var mutex sync.Mutex
+	extensionRegex := regexp.MustCompile(`\.[a-zA-Z0-9]+$`)
+	var i int32
+
+	if *recreate {
+		log.Printf("Recreating all files first")
+		for _, file := range flag.Args() {
+			wg.Add(1)
+			go func(file string) {
+				defer wg.Done()
+				res := extensionRegex.FindAllString(file, -1)
+				if len(res) == 0 {
+					log.Printf("No extension found for file %s", file)
+					return
+				}
+				extension := res[0]
+				bckpFile := file + ".bak"
+
+				_, err := os.Stat(bckpFile)
+				if !os.IsNotExist(err) {
+					log.Printf("File %s already exists", bckpFile)
+					return
+				}
+	
+				log.Printf("%s -> %s", file, bckpFile)
+				err = os.Rename(file, bckpFile)
+				if err != nil {
+					log.Printf("Error renaming file %s to %s: %s", file, bckpFile, err)
+				}
+				
+				mapMutex.Lock()
+				originalExtensions[bckpFile] = extension
+				mapMutex.Unlock()
+			}(file)
+		}
+	}
+	wg.Wait()
+	wg = sync.WaitGroup{}
+
+	for _, file := range flag.Args() {
+		wg.Add(1)
+		go func(file string) {
+			defer wg.Done()
+			if *recreate {
+				file = file + ".bak"
+			}
+
+			info, err := os.Stat(file)
+			if os.IsNotExist(err) {
+				log.Printf("File %s does not exist", file)
+				return
+			}
+
+			if info.IsDir() {
+				log.Printf("File %s is a directory", file)
+				return
+			}
+
+			mutex.Lock()
+			atomic.AddInt32(&i, 1)
+			newFile := fmt.Sprintf(nameFormat, i)
+			mutex.Unlock()
+
+			res := extensionRegex.FindAllString(file, -1)
+			if len(res) == 0 {
+				log.Printf("No extension found for file %s", file)
+				return
+			}
+			extension := res[0]
+
+			mapMutex.RLock()
+			prevExtension, ok := originalExtensions[file]
+			mapMutex.RUnlock()
+			if ok {
+				extension = prevExtension
+			}
+
+			newFile = newFile + extension
+
+			_, err = os.Stat(newFile)
+			if !os.IsNotExist(err) {
+				log.Printf("File %s already exists", newFile)
+				return
+			}
+
+			log.Printf("%s -> %s", file, newFile)
+			err = os.Rename(file, newFile)
+			if err != nil {
+				log.Printf("Error renaming file %s to %s: %s", file, newFile, err)
+				return
+			}
+		}(file)
+	}
+	wg.Wait()
+}