package archive

import (
	"archive/tar"
	"errors"
	"io"
	"io/fs"
	"path/filepath"
)

func TarDirectory(src fs.FS, root string, writer io.Writer) (err error) {
	tw := tar.NewWriter(writer)

	defer func() {
		err = errors.Join(err, tw.Close())
	}()

	return fs.WalkDir(src, root, func(path string, d fs.DirEntry, err error) error {
		fileInfo, err := d.Info()
		if err != nil {
			return err
		}

		header, err := tar.FileInfoHeader(fileInfo, path)
		if err != nil {
			return err
		}

		header.Name = filepath.ToSlash(path)

		if err := tw.WriteHeader(header); err != nil {
			return err
		}

		if !d.IsDir() {
			f, err := src.Open(path)
			if err != nil {
				return err
			}

			if _, err := io.Copy(tw, f); err != nil {
				return err
			}
		}

		return nil
	})
}