Add archive-as-folder navigation and extraction copy flow

internal/fs/archive.go

@@ -0,0 +1,158 @@
+package vfs
+
+import (
+	"archive/tar"
+	"archive/zip"
+	"compress/gzip"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+func ExtractArchiveToTemp(sourcePath string) (string, error) {
+	tempDir, err := os.MkdirTemp("", "vcom-archive-")
+	if err != nil {
+		return "", err
+	}
+	cleanupOnErr := func(extractErr error) (string, error) {
+		_ = os.RemoveAll(tempDir)
+		return "", extractErr
+	}
+
+	sourceLower := strings.ToLower(sourcePath)
+	switch {
+	case strings.HasSuffix(sourceLower, ".zip"):
+		if err := extractZipArchive(sourcePath, tempDir); err != nil {
+			return cleanupOnErr(err)
+		}
+	case strings.HasSuffix(sourceLower, ".tar"):
+		if err := extractTarArchive(sourcePath, tempDir, false); err != nil {
+			return cleanupOnErr(err)
+		}
+	case strings.HasSuffix(sourceLower, ".tar.gz"), strings.HasSuffix(sourceLower, ".tgz"):
+		if err := extractTarArchive(sourcePath, tempDir, true); err != nil {
+			return cleanupOnErr(err)
+		}
+	default:
+		return cleanupOnErr(fmt.Errorf("archive format is not supported: %s", filepath.Ext(sourcePath)))
+	}
+
+	return tempDir, nil
+}
+
+func extractZipArchive(sourcePath string, targetDir string) error {
+	reader, err := zip.OpenReader(sourcePath)
+	if err != nil {
+		return err
+	}
+	defer reader.Close()
+
+	for _, file := range reader.File {
+		relPath, ok := safeArchivePath(file.Name)
+		if !ok {
+			continue
+		}
+		fullPath := filepath.Join(targetDir, relPath)
+
+		if file.FileInfo().IsDir() {
+			if err := os.MkdirAll(fullPath, 0o755); err != nil {
+				return err
+			}
+			continue
+		}
+
+		if err := os.MkdirAll(filepath.Dir(fullPath), 0o755); err != nil {
+			return err
+		}
+		src, err := file.Open()
+		if err != nil {
+			return err
+		}
+		if err := writeArchiveFile(fullPath, src, file.Mode()); err != nil {
+			src.Close()
+			return err
+		}
+		src.Close()
+	}
+	return nil
+}
+
+func extractTarArchive(sourcePath string, targetDir string, gzipped bool) error {
+	file, err := os.Open(sourcePath)
+	if err != nil {
+		return err
+	}
+	defer file.Close()
+
+	var reader io.Reader = file
+	if gzipped {
+		gzipReader, err := gzip.NewReader(file)
+		if err != nil {
+			return err
+		}
+		defer gzipReader.Close()
+		reader = gzipReader
+	}
+
+	tarReader := tar.NewReader(reader)
+	for {
+		header, err := tarReader.Next()
+		if err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		relPath, ok := safeArchivePath(header.Name)
+		if !ok {
+			continue
+		}
+		fullPath := filepath.Join(targetDir, relPath)
+
+		switch header.Typeflag {
+		case tar.TypeDir:
+			if err := os.MkdirAll(fullPath, 0o755); err != nil {
+				return err
+			}
+		case tar.TypeReg, tar.TypeRegA:
+			if err := os.MkdirAll(filepath.Dir(fullPath), 0o755); err != nil {
+				return err
+			}
+			if err := writeArchiveFile(fullPath, tarReader, os.FileMode(header.Mode)); err != nil {
+				return err
+			}
+		}
+	}
+
+	return nil
+}
+
+func writeArchiveFile(path string, source io.Reader, mode os.FileMode) error {
+	if mode == 0 {
+		mode = 0o644
+	}
+	output, err := os.OpenFile(path, os.O_CREATE|os.O_WRONLY|os.O_TRUNC, mode.Perm())
+	if err != nil {
+		return err
+	}
+	defer output.Close()
+
+	_, err = io.Copy(output, source)
+	return err
+}
+
+func safeArchivePath(name string) (string, bool) {
+	clean := filepath.Clean(name)
+	if clean == "." || clean == string(filepath.Separator) {
+		return "", false
+	}
+	if filepath.IsAbs(clean) {
+		return "", false
+	}
+	if clean == ".." || strings.HasPrefix(clean, ".."+string(filepath.Separator)) {
+		return "", false
+	}
+	return clean, true
+}