package storage

import (
	"archive/zip"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"strings"
)

func unzipToDir(readerAt io.ReaderAt, size int64, target string) error {
	if err := os.MkdirAll(target, 0o755); err != nil {
		return err
	}
	zr, err := zip.NewReader(readerAt, size)
	if err != nil {
		return err
	}
	for _, f := range zr.File {
		name := filepath.Clean(f.Name)
		if strings.HasPrefix(name, "..") {
			return fmt.Errorf("invalid zip entry path: %s", f.Name)
		}
		fullPath := filepath.Join(target, name)
		if f.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 := f.Open()
		if err != nil {
			return err
		}
		dst, err := os.Create(fullPath)
		if err != nil {
			src.Close()
			return err
		}
		if _, err := io.Copy(dst, src); err != nil {
			dst.Close()
			src.Close()
			return err
		}
		dst.Close()
		src.Close()
	}
	return nil
}