add zip and parity stuff

fileUtilities/zip.go

@@ -0,0 +1,86 @@
+package fileUtilities
+
+import (
+	"archive/zip"
+	"fmt"
+	"forever-files/types"
+	"io"
+	"os"
+	"path"
+	"strings"
+)
+
+func CreateZip(fileName, outDir, baseDir string, partition []types.FileMetadata) error {
+	// Create a buffer to write our archive to.
+	outFile := path.Join(outDir, fileName+".zip")
+	zipFile, err := os.OpenFile(outFile, os.O_CREATE|os.O_WRONLY, 0644)
+	if err != nil {
+		return fmt.Errorf("error opening/creating zip file: %w", err)
+	}
+
+	// Create a new zip archive.
+	w := zip.NewWriter(zipFile)
+
+	files := prepFiles(baseDir, partition)
+
+	for _, file := range files {
+		zf, err := w.Create(file.Name)
+		if err != nil {
+			return fmt.Errorf("error creating zip file: %w", err)
+		}
+		f, err := os.Open(file.Path)
+		if err != nil {
+			fmt.Println(fmt.Sprintf("error opening file: %v", err))
+			fmt.Println(fmt.Sprintf("skipping file: %v", file.Path))
+			continue
+		}
+		if _, err := io.Copy(zf, f); err != nil {
+			return fmt.Errorf("error copying file to zip file: %w", err)
+		}
+		err = f.Close()
+		if err != nil {
+			return fmt.Errorf("error closing file: %w", err)
+		}
+	}
+
+	// Make sure to check the error on Close.
+	err = w.Close()
+	if err != nil {
+		return fmt.Errorf("error closing zip file: %w", err)
+	}
+
+	err = zipFile.Close()
+	if err != nil {
+		return fmt.Errorf("error closing zip file: %w", err)
+	}
+
+	return nil
+}
+
+func prepFiles(baseDir string, partition []types.FileMetadata) []struct {
+	Name, Path string
+} {
+	var files []struct {
+		Name, Path string
+	}
+	for _, file := range partition {
+		filePath := path.Join(file.Path, file.Name)
+
+		// from zip.Create documentation:
+		// ...The name must be a relative path: it must not start with a
+		// drive letter (e.g. C:) or leading slash, and only forward slashes
+		// are allowed...
+		fileName := strings.Replace(replaceBackslashes(strings.Replace(filePath, baseDir, "", 1)), "/", "", 1)
+		files = append(files, struct {
+			Name, Path string
+		}{
+			Name: fileName,
+			Path: filePath,
+		})
+	}
+	return files
+}
+
+func replaceBackslashes(input string) string {
+	return strings.ReplaceAll(input, "\\", "/")
+}