clear.go

package leet

import (
	"bytes"
	"fmt"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"
	"strings"
	"syscall"
)

type BackupClear struct {
	Dir      string `json:"dir"`
	Language string `json:"language"`
}

func (th BackupClear) Backup(override bool) error {
	solutionsDir := strings.Replace(th.Dir, "questions", "solutions", 1)

	if f, err := os.Stat(solutionsDir); err == nil && f.IsDir() && !override {
		err = fmt.Errorf("%s 已经备份, 使用 `--override-backup` 强制备份", solutionsDir)
		return err
	}

	err := CopyDirectory(th.Dir, solutionsDir)
	if err != nil {
		panic(err)
	}

	return err
}

func (th BackupClear) Clear() (err error) {
	switch th.Language {
	case "golang":
		return GolangClear(th.Dir)
	}

	return
}

func CopyFile(dstName, srcName string) (written int64, err error) {
	s, err := ioutil.ReadFile(srcName)
	if err != nil {
		return
	}

	d, err := ioutil.ReadFile(dstName)
	if err != nil {
		return
	}

	if bytes.Equal(s, d) {
		return
	}

	src, err := os.Open(srcName)
	if err != nil {
		return
	}
	defer src.Close()
	dst, err := os.OpenFile(dstName, os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0644)
	if err != nil {
		return
	}

	defer dst.Close()
	return io.Copy(dst, src)
}

func CopyDirectory(scrDir, dest string) error {
	entries, err := ioutil.ReadDir(scrDir)
	if err != nil {
		return err
	}
	for _, entry := range entries {
		sourcePath := filepath.Join(scrDir, entry.Name())
		destPath := filepath.Join(dest, entry.Name())
		if err := CreateIfNotExists(filepath.Dir(destPath), 0755); err != nil {
			return err
		}

		fileInfo, err := os.Stat(sourcePath)
		if err != nil {
			return err
		}

		stat, ok := fileInfo.Sys().(*syscall.Stat_t)
		if !ok {
			return fmt.Errorf("failed to get raw syscall.Stat_t data for '%s'", sourcePath)
		}

		switch fileInfo.Mode() & os.ModeType {
		case os.ModeDir:
			if err := CreateIfNotExists(destPath, 0755); err != nil {
				return err
			}
			if err := CopyDirectory(sourcePath, destPath); err != nil {
				return err
			}
		case os.ModeSymlink:
			if err := CopySymLink(sourcePath, destPath); err != nil {
				return err
			}
		default:
			if err := Copy(sourcePath, destPath); err != nil {
				return err
			}
		}

		if err := os.Lchown(destPath, int(stat.Uid), int(stat.Gid)); err != nil {
			return err
		}

		isSymlink := entry.Mode()&os.ModeSymlink != 0
		if !isSymlink {
			if err := os.Chmod(destPath, entry.Mode()); err != nil {
				return err
			}
		}
	}
	return nil
}

func Copy(srcFile, dstFile string) error {
	out, err := os.Create(dstFile)
	if err != nil {
		return err
	}

	defer out.Close()

	in, err := os.Open(srcFile)
	defer in.Close()
	if err != nil {
		return err
	}

	_, err = io.Copy(out, in)
	if err != nil {
		return err
	}

	return nil
}

func Exists(filePath string) bool {
	if _, err := os.Stat(filePath); os.IsNotExist(err) {
		return false
	}

	return true
}

func CreateIfNotExists(dir string, perm os.FileMode) error {
	if Exists(dir) {
		return nil
	}

	if err := os.MkdirAll(dir, perm); err != nil {
		return fmt.Errorf("failed to create directory: '%s', error: '%s'", dir, err.Error())
	}

	return nil
}

func CopySymLink(source, dest string) error {
	link, err := os.Readlink(source)
	if err != nil {
		return err
	}
	return os.Symlink(link, dest)
}