From d8666cb5d3acc25a77f3d84f92c52301687dd6ae Mon Sep 17 00:00:00 2001
From: Rico <d-Rickyy-b@users.noreply.github.com>
Date: Wed, 30 Dec 2020 20:22:41 +0100
Subject: [PATCH] refactor: move archive code to archiver package

---
 archiver/archive.go | 157 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 157 insertions(+)
 create mode 100644 archiver/archive.go

diff --git a/archiver/archive.go b/archiver/archive.go
new file mode 100644
index 0000000..016191d
--- /dev/null
+++ b/archiver/archive.go
@@ -0,0 +1,157 @@
+package archiver
+
+import (
+	"archive/tar"
+	"backmeup/config"
+	"github.com/cheggaaa/pb/v3"
+	"github.com/klauspost/compress/gzip"
+	"github.com/klauspost/compress/zip"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+type BackupFileMetadata struct {
+	Path           string
+	BackupBasePath string
+}
+
+func getPathInArchive(filePath string, backupBasePath string, unit config.Unit) string {
+	// Remove the base Path from the file Path within the archiver, if option is set
+	pathInArchive := filePath
+
+	if !unit.UseAbsolutePaths {
+		parentBasePath := filepath.Dir(backupBasePath)
+		pathInArchive = strings.ReplaceAll(filePath, parentBasePath, "")
+
+		pathInArchive = strings.TrimPrefix(pathInArchive, "\\")
+	}
+
+	return pathInArchive
+}
+
+func WriteArchive(backupArchivePath string, filesToBackup []BackupFileMetadata, unit config.Unit) {
+	archiveFile, err := os.Create(backupArchivePath)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	defer archiveFile.Close()
+
+	switch unit.ArchiveType {
+	case "tar.gz":
+		writeTar(archiveFile, filesToBackup, unit)
+	case "zip":
+		writeZip(archiveFile, filesToBackup, unit)
+	default:
+		log.Fatalf("Can't handle archiver type '%s'", unit.ArchiveType)
+	}
+}
+
+func writeTar(archiveFile *os.File, filesToBackup []BackupFileMetadata, unit config.Unit) {
+	// set up the gzip and tar writer
+	gw := gzip.NewWriter(archiveFile)
+	defer gw.Close()
+
+	tw := tar.NewWriter(gw)
+	defer tw.Close()
+
+	// Init progress bar
+	bar := pb.StartNew(len(filesToBackup))
+
+	for i := range filesToBackup {
+		fileMetadata := filesToBackup[i]
+		filePath := fileMetadata.Path
+
+		pathInArchive := getPathInArchive(filePath, fileMetadata.BackupBasePath, unit)
+
+		if err := addFileToTar(tw, filePath, pathInArchive); err != nil {
+			log.Fatalln(err)
+		}
+
+		bar.Increment()
+	}
+
+	bar.Finish()
+}
+
+func writeZip(archiveFile *os.File, filesToBackup []BackupFileMetadata, unit config.Unit) {
+	zw := zip.NewWriter(archiveFile)
+	defer zw.Close()
+
+	bar := pb.StartNew(len(filesToBackup))
+
+	for i := range filesToBackup {
+		fileMetadata := filesToBackup[i]
+		filePath := fileMetadata.Path
+
+		pathInArchive := getPathInArchive(filePath, fileMetadata.BackupBasePath, unit)
+
+		if err := addFileToZip(zw, filePath, pathInArchive); err != nil {
+			log.Fatalln(err)
+		}
+
+		bar.Increment()
+	}
+
+	bar.Finish()
+}
+
+func addFileToTar(tw *tar.Writer, path string, pathInArchive string) error {
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	if stat, err := file.Stat(); err == nil {
+		// now lets create the header as needed for this file within the tarball
+		header := new(tar.Header)
+		header.Format = tar.FormatGNU
+		header.Name = pathInArchive
+		header.Size = stat.Size()
+		header.Mode = int64(stat.Mode())
+		header.ModTime = stat.ModTime()
+		// write the header to the tarball archiver
+		if err := tw.WriteHeader(header); err != nil {
+			return err
+		}
+		// copy the file data to the tarball
+		if _, err := io.Copy(tw, file); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}
+
+func addFileToZip(zw *zip.Writer, path string, pathInArchive string) error {
+	file, err := os.Open(path)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	if stat, err := file.Stat(); err == nil {
+		header, headerErr := zip.FileInfoHeader(stat)
+		if headerErr != nil {
+			return headerErr
+		}
+
+		header.Name = pathInArchive
+		// write the header to the zip archiver
+		writer, headerErr := zw.CreateHeader(header)
+		if headerErr != nil {
+			return err
+		}
+		// copy the file data to the zip
+		if _, err := io.Copy(writer, file); err != nil {
+			return err
+		}
+	} else {
+		return err
+	}
+
+	return nil
+}