package compression

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

type TGZHandler struct {
}

func NewTGZHandler() *TGZHandler {
	return &TGZHandler{}
}

// UNTarGZ 解压tar.gz文件到指定目录，包含顶层文件夹
func (z *TGZHandler) UNTarGZ(src, dst string) error {
	archive, err := os.Open(src)
	if err != nil {
		return err
	}
	defer func(archive *os.File) {
		err := archive.Close()
		if err != nil {
			return
		}
	}(archive)

	gr, err := gzip.NewReader(archive)
	if err != nil {
		return err
	}

	defer func(gr *gzip.Reader) {
		err := gr.Close()
		if err != nil {
			return
		}
	}(gr)

	tr := tar.NewReader(gr)
	for {
		f, err := tr.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			return err
		}
		filePath := path.Join(dst, f.Name)
		if err := os.MkdirAll(filepath.Dir(filePath), os.ModePerm); err != nil {
			return err
		}

		if f.FileInfo().IsDir() {
			err := os.MkdirAll(filePath, os.ModePerm)
			if err != nil {
				return err
			}
			continue
		} else {
			fileName := path.Join(dst, f.Name)
			fw, err := os.OpenFile(fileName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.FileMode(f.Mode))
			defer func(fw *os.File) {
				err := fw.Close()
				if err != nil {
					return
				}
			}(fw)
			if err != nil {
				return err
			}
			if _, err := io.Copy(fw, tr); err != nil {
				return err
			}
		}

	}

	return nil
}

// UNTarGZTo 解压tar.gz文件到指定目录，不包含顶层文件夹，只是将文件解压到指定目录
func (z *TGZHandler) UNTarGZTo(src, dst string) error {
	archive, err := os.Open(src)
	if err != nil {
		return err
	}
	defer func(archive *os.File) {
		err := archive.Close()
		if err != nil {
			return
		}
	}(archive)

	gr, err := gzip.NewReader(archive)
	if err != nil {
		return err
	}

	defer func(gr *gzip.Reader) {
		err := gr.Close()
		if err != nil {
			return
		}
	}(gr)

	tr := tar.NewReader(gr)
	for {
		f, err := tr.Next()
		if err == io.EOF {
			break
		}
		if err != nil {
			return err
		}
		filePath := path.Join(dst, f.Name)
		if err := os.MkdirAll(filepath.Dir(filePath), os.ModePerm); err != nil {
			return err
		}

		if f.FileInfo().IsDir() {
			err := os.MkdirAll(filePath, os.ModePerm)
			if err != nil {
				return err
			}
			continue
		} else {
			splitPath := strings.Split(f.Name, string(os.PathSeparator))
			targetPath := strings.Join(splitPath[1:], string(os.PathSeparator))
			filePath := filepath.Join(dst, targetPath)
			fw, err := os.OpenFile(filePath, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, os.FileMode(f.Mode))
			defer func(fw *os.File) {
				err := fw.Close()
				if err != nil {
					return
				}
			}(fw)
			if err != nil {
				return err
			}
			if _, err := io.Copy(fw, tr); err != nil {
				return err
			}
		}

	}

	return nil
}