/*
Copyright 2016 The Kubernetes Authors All rights reserved

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package archive

import (
	"archive/tar"
	"io"
	"os"
	"path/filepath"
	"strings"
)

/*
CreateTarball creates a tarball for source and dumps it to target path

Function modified and added from https://github.com/mholt/archiver/blob/master/tar.go
*/
func CreateTarball(source, target string) error {
	tarfile, err := os.Create(target)
	if err != nil {
		return err
	}
	defer tarfile.Close()

	tarball := tar.NewWriter(tarfile)
	defer tarball.Close()

	info, err := os.Stat(source)
	if err != nil {
		return nil
	}

	var baseDir string
	if info.IsDir() {
		baseDir = filepath.Base(source)
	}

	return filepath.Walk(source,
		func(path string, info os.FileInfo, err error) error {
			if baseDir == path {
				return nil
			}
			if err != nil {
				return err
			}
			header, err := tar.FileInfoHeader(info, info.Name())
			if err != nil {
				return err
			}

			if baseDir != "" {
				if strings.HasSuffix(source, "/") {
					header.Name = strings.TrimPrefix(path, source)
				} else {
					header.Name = filepath.Join(baseDir, strings.TrimPrefix(path, source))
				}
				//println("Header name", header.Name)
			}

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

			if info.IsDir() {
				return nil
			}

			file, err := os.Open(path)
			if err != nil {
				return err
			}
			defer file.Close()
			_, err = io.Copy(tarball, file)
			return err
		})
}