package gzip

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

// Compress
func Compress(src, dest string) error {
	d, err := os.Create(dest)
	if err != nil {
		return err
	}
	defer d.Close()
	gw := gzip.NewWriter(d)
	defer gw.Close()
	tw := tar.NewWriter(gw)
	defer tw.Close()
	err = filepath.Walk(src, func(filePath string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if !info.IsDir() {
			header, err := tar.FileInfoHeader(info, ``)
			if err != nil {
				return err
			}
			header.Name = strings.TrimPrefix(filePath, src+"/")
			err = tw.WriteHeader(header)
			if err != nil {
				return err
			}
			f, err := os.Open(filePath)
			if err != nil {
				return err
			}
			defer f.Close()
			_, err = io.Copy(tw, f)
			if err != nil {
				return err
			}
		}
		return nil
	})
	if err != nil {
		return err
	}
	return nil
}

// DeCompress
func DeCompress(src, dest string) error {
	srcFile, err := os.Open(src)
	if err != nil {
		return err
	}
	defer srcFile.Close()
	gr, err := gzip.NewReader(srcFile)
	if err != nil {
		return err
	}
	defer gr.Close()
	tr := tar.NewReader(gr)
	for {
		hdr, err := tr.Next()
		if err != nil {
			if err == io.EOF {
				break
			} else {
				return err
			}
		}
		fileName := path.Join(dest, hdr.Name)
		err = os.MkdirAll(filepath.Dir(fileName), os.ModePerm)
		if err != nil {
			return err
		}
		f, err := os.Create(fileName)
		if err != nil {
			return err
		}
		defer f.Close()
		_, err = io.Copy(f, tr)
		if err != nil {
			return err
		}
	}
	return nil
}