From 9176c33eee089270b3cca6e8044d2aa19d5a2f5c Mon Sep 17 00:00:00 2001
From: Urko <urko@fungimail.com>
Date: Mon, 10 Jul 2023 16:24:24 +0200
Subject: [PATCH] feat: delete files after upload is completed

---
 cmd/main.go                    |  1 +
 internal/services/backblaze.go | 55 ++++++++++++++++++++++++++--------
 2 files changed, 43 insertions(+), 13 deletions(-)

diff --git a/cmd/main.go b/cmd/main.go
index b50b063..e5bb91e 100644
--- a/cmd/main.go
+++ b/cmd/main.go
@@ -15,6 +15,7 @@ var rootCmd = &cobra.Command{
 	Short: "Backblaze backup tool",
 	Long:  `A tool to backup files and directories to Backblaze.`,
 	Run: func(cmd *cobra.Command, args []string) {
+		log.SetFlags(log.Lmicroseconds)
 		filePath, err := cmd.Flags().GetString("file")
 		if err != nil {
 			log.Fatalln("file %w", err)
diff --git a/internal/services/backblaze.go b/internal/services/backblaze.go
index 680ea8b..e372f86 100644
--- a/internal/services/backblaze.go
+++ b/internal/services/backblaze.go
@@ -10,6 +10,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
+	"strings"
 	"sync"
 
 	"github.com/kurin/blazer/b2"
@@ -84,9 +85,13 @@ func (b *BackBalze) Sync() error {
 	}
 
 	if b.dir != "" {
-		if err := cleanBucket(ctx, bc); err != nil {
-			return fmt.Errorf("clearBucket %w", err)
+		oldFiles, err := bucketFiles(ctx, bc)
+		if err != nil {
+			return fmt.Errorf("bucketFiles %w", err)
 		}
+		log.Println(strings.Repeat("*", 40))
+		log.Println("oldFiles to clean:\n\t\t" + strings.Join(oldFiles, "\n\t\t"))
+		log.Println(strings.Repeat("*", 40))
 
 		fileChan := make(chan string)
 		uploadSem := semaphore.NewWeighted(maxConcurrentWeight)
@@ -108,6 +113,7 @@ func (b *BackBalze) Sync() error {
 						weight = 2
 					}
 					if err := uploadSem.Acquire(ctx, weight); err == nil {
+						log.Println("start copying file", src)
 						if err := copyFile(ctx, bc, src); err != nil {
 							log.Printf("error copying file %s: %v\n", src, err)
 						}
@@ -120,7 +126,7 @@ func (b *BackBalze) Sync() error {
 		}
 
 		// Walk the directory and send files to the channel for uploading
-		err := filepath.WalkDir(b.dir, func(path string, d fs.DirEntry, err error) error {
+		err = filepath.WalkDir(b.dir, func(path string, d fs.DirEntry, err error) error {
 			if err != nil {
 				return err
 			}
@@ -136,6 +142,11 @@ func (b *BackBalze) Sync() error {
 		// Close the channel (no more files to send)
 		close(fileChan)
 		wg.Wait()
+
+		// Cleanup old files after backup is completed
+		if err := cleanBucket(ctx, bc, oldFiles); err != nil {
+			return fmt.Errorf("cleanBucket %w", err)
+		}
 	}
 
 	log.Println("copied successfully")
@@ -143,7 +154,6 @@ func (b *BackBalze) Sync() error {
 }
 
 func copyFile(ctx context.Context, bucket *b2.Bucket, src string) error {
-	log.Println("copying file", src)
 	f, err := os.Open(src)
 	if err != nil {
 		return err
@@ -162,16 +172,37 @@ func copyFile(ctx context.Context, bucket *b2.Bucket, src string) error {
 	return w.Close()
 }
 
-func cleanBucket(ctx context.Context, bucket *b2.Bucket) error {
-	bucketIter := bucket.List(ctx)
-	if bucketIter == nil {
-		return fmt.Errorf("bucket list cannot be nil")
+func cleanBucket(ctx context.Context, bucket *b2.Bucket, files []string) error {
+	var errorBuilder strings.Builder
+	for _, v := range files {
+		obj := bucket.Object(v)
+		if obj == nil {
+			log.Println("object is nil", v)
+			continue
+		}
+		if err := obj.Delete(ctx); err != nil {
+			errorBuilder.WriteString(fmt.Errorf("error deleting %s : %w", v, err).Error())
+			errorBuilder.WriteString("; ")
+		}
 	}
 
+	if errorBuilder.Len() > 0 {
+		return errors.New(errorBuilder.String())
+	}
+
+	return nil
+}
+
+func bucketFiles(ctx context.Context, bucket *b2.Bucket) ([]string, error) {
+	bucketIter := bucket.List(ctx)
+	if bucketIter == nil {
+		return nil, fmt.Errorf("bucket list cannot be nil")
+	}
+	var files []string
 	for {
 		if !bucketIter.Next() {
 			if bucketIter.Err() != nil {
-				return fmt.Errorf("bucketIter err %w", bucketIter.Err())
+				return nil, fmt.Errorf("bucketIter err %w", bucketIter.Err())
 			}
 			break
 		}
@@ -179,9 +210,7 @@ func cleanBucket(ctx context.Context, bucket *b2.Bucket) error {
 			log.Println("bucketIter Object is nil")
 			continue
 		}
-		if err := bucketIter.Object().Delete(ctx); err != nil {
-			return fmt.Errorf("bucketIter.Object().Delete() %s | err %w", bucketIter.Object().Name(), err)
-		}
+		files = append(files, bucketIter.Object().Name())
 	}
-	return nil
+	return files, nil
 }