dnote/utils/utils.go

package utils

import (
	"bufio"
	"io"
	"io/ioutil"
	"os"
	"path/filepath"

	"github.com/dnote/cli/log"
	"github.com/pkg/errors"
	"github.com/satori/go.uuid"
)

// GenerateUUID returns a uid
func GenerateUUID() string {
	return uuid.NewV4().String()
}

func getInput() (string, error) {
	reader := bufio.NewReader(os.Stdin)
	input, err := reader.ReadString('\n')
	if err != nil {
		return "", errors.Wrap(err, "reading stdin")
	}

	return input, nil
}

// AskConfirmation prompts for user input to confirm a choice
func AskConfirmation(question string, optimistic bool) (bool, error) {
	var choices string
	if optimistic {
		choices = "(Y/n)"
	} else {
		choices = "(y/N)"
	}

	log.Printf("%s %s: ", question, choices)

	res, err := getInput()
	if err != nil {
		return false, errors.Wrap(err, "Failed to get user input")
	}

	confirmed := res == "y\n" || res == "y\r\n"

	if optimistic {
		confirmed = confirmed || res == "\n" || res == "\r\n"
	}

	return confirmed, nil
}

// FileExists checks if the file exists at the given path
func FileExists(filepath string) bool {
	_, err := os.Stat(filepath)
	return !os.IsNotExist(err)
}

// CopyFile copies a file from the src to dest
func CopyFile(src, dest string) error {
	in, err := os.Open(src)
	if err != nil {
		return errors.Wrap(err, "opening the input file")
	}
	defer in.Close()

	out, err := os.Create(dest)
	if err != nil {
		return errors.Wrap(err, "creating the output file")
	}

	if _, err = io.Copy(out, in); err != nil {
		return errors.Wrap(err, "copying the file content")
	}

	if err = out.Sync(); err != nil {
		return errors.Wrap(err, "flushing the output file to disk")
	}

	fi, err := os.Stat(src)
	if err != nil {
		return errors.Wrap(err, "getting the file info for the input file")
	}

	if err = os.Chmod(dest, fi.Mode()); err != nil {
		return errors.Wrap(err, "copying permission to the output file")
	}

	// Close the output file
	if err = out.Close(); err != nil {
		return errors.Wrap(err, "closing the output file")
	}

	return nil
}

// CopyDir copies a directory from src to dest, recursively copying nested
// directories
func CopyDir(src, dest string) error {
	srcPath := filepath.Clean(src)
	destPath := filepath.Clean(dest)

	fi, err := os.Stat(srcPath)
	if err != nil {
		return errors.Wrap(err, "getting the file info for the input")
	}
	if !fi.IsDir() {
		return errors.New("source is not a directory")
	}

	_, err = os.Stat(dest)
	if err != nil && !os.IsNotExist(err) {
		return errors.Wrap(err, "looking up the destination")
	}

	err = os.MkdirAll(dest, fi.Mode())
	if err != nil {
		return errors.Wrap(err, "creating destination")
	}

	entries, err := ioutil.ReadDir(src)
	if err != nil {
		return errors.Wrap(err, "reading the directory listing for the input")
	}

	for _, entry := range entries {
		srcEntryPath := filepath.Join(srcPath, entry.Name())
		destEntryPath := filepath.Join(destPath, entry.Name())

		if entry.IsDir() {
			if err = CopyDir(srcEntryPath, destEntryPath); err != nil {
				return errors.Wrapf(err, "copying %s", entry.Name())
			}
		} else {
			if err = CopyFile(srcEntryPath, destEntryPath); err != nil {
				return errors.Wrapf(err, "copying %s", entry.Name())
			}
		}
	}

	return nil
}