helper.go

package utils

import (
	"archive/zip"
	"bufio"
	"bytes"
	"context"
	"crypto/sha1"
	"encoding/base64"
	"fmt"
	"io"
	"math/rand"
	"net/url"
	"os"
	"os/exec"
	"path"
	"path/filepath"
	"regexp"
	"strconv"
	"strings"

	//"syscall"
	"text/template"
	"time"

	"github.com/mitchellh/go-homedir"
)

// CalcTimeout calculate timeout
func CalcTimeout(raw string) int {
	raw = strings.ToLower(strings.TrimSpace(raw))
	seconds := raw
	multiply := 1

	matched, _ := regexp.MatchString(`.*[a-z]`, raw)
	if matched {
		unitTime := fmt.Sprintf("%c", raw[len(raw)-1])
		seconds = raw[:len(raw)-1]
		switch unitTime {
		case "s":
			multiply = 1
			break
		case "m":
			multiply = 60
			break
		case "h":
			multiply = 3600
			break
		}
	}

	timeout, err := strconv.Atoi(seconds)
	if err != nil {
		return 0
	}
	return timeout * multiply
}

// GetDomain get domain from the URL
func GetDomain(raw string) (string, error) {
	u, err := url.Parse(raw)
	if err == nil {
		return u.Hostname(), nil
	}
	return raw, err
}

// EmptyDir check if directory is empty or not
func EmptyDir(dir string) bool {
	if !FolderExists(dir) {
		return true
	}
	f, err := os.Open(NormalizePath(dir))
	if err != nil {
		return false
	}
	defer f.Close()

	_, err = f.Readdirnames(1)
	if err == io.EOF {
		return true
	}
	return false
}

// EmptyFile check if file is empty or not
func EmptyFile(filename string, num int) bool {
	filename = NormalizePath(filename)
	if !FileExists(filename) {
		return true
	}
	data := ReadingLines(filename)
	if len(data) > num {
		return false
	}
	return true
}

// StrToInt string to int
func StrToInt(data string) int {
	i, err := strconv.Atoi(data)
	if err != nil {
		return 0
	}
	return i
}

// GetOSEnv get environment variable
func GetOSEnv(name string, defaultValue string) string {
	variable, ok := os.LookupEnv(name)
	if !ok {
		if defaultValue != "" {
			return defaultValue
		}
		return name
	}
	return variable
}

// MakeDir just make a folder
func MakeDir(folder string) {
	folder = NormalizePath(folder)
	os.MkdirAll(folder, 0750)
}

// GetCurrentDay get current day
func GetCurrentDay() string {
	currentTime := time.Now()
	return fmt.Sprintf("%v", currentTime.Format("2006-01-02_3:4:5"))
}

// NormalizePath the path
func NormalizePath(path string) string {
	if strings.HasPrefix(path, "~") {
		path, _ = homedir.Expand(path)
	}
	return path
}

// GetFileContent Reading file and return content of it
func GetFileContent(filename string) string {
	var result string
	if strings.Contains(filename, "~") {
		filename, _ = homedir.Expand(filename)
	}
	file, err := os.Open(filename)
	if err != nil {
		return result
	}
	defer file.Close()
	b, err := io.ReadAll(file)
	if err != nil {
		return result
	}
	return string(b)
}

// ReadingLines Reading file and return content as []string
func ReadingLines(filename string) []string {
	var result []string
	if strings.HasPrefix(filename, "~") {
		filename, _ = homedir.Expand(filename)
	}
	file, err := os.Open(filename)
	if err != nil {
		return result
	}
	defer file.Close()

	// scanner := bufio.NewScanner(file)
	// for scanner.Scan() {
	// 	val := strings.TrimSpace(scanner.Text())
	// 	if val == "" {
	// 		continue
	// 	}
	// 	result = append(result, val)
	// }

	// increase the buffer size
	scanner := bufio.NewScanner(file)
	scanner.Buffer(make([]byte, 0, 64*1024), 1024*1024)
	for scanner.Scan() {
		val := strings.TrimSpace(scanner.Text())
		if val == "" {
			continue
		}
		result = append(result, val)
	}

	if err := scanner.Err(); err != nil {
		return result
	}
	return result
}

// Cat Reading file and return content as []string
func Cat(filename string) {
	filename = NormalizePath(filename)
	if !FileExists(filename) {
		return
	}
	file, err := os.Open(filename)
	if err != nil {
		return
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		line := strings.TrimSpace(scanner.Text())
		if line == "" {
			continue
		}
		fmt.Println(line)
	}
	return
}

// ReadingFileUnique Reading file and return content as []string
func ReadingFileUnique(filename string) []string {
	var result []string
	if strings.Contains(filename, "~") {
		filename, _ = homedir.Expand(filename)
	}
	file, err := os.Open(filename)
	if err != nil {
		return result
	}
	defer file.Close()

	seen := make(map[string]bool)
	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		val := strings.TrimSpace(scanner.Text())
		// unique stuff
		if val == "" {
			continue
		}
		if seen[val] {
			continue
		}

		seen[val] = true
		result = append(result, val)
	}

	if err := scanner.Err(); err != nil {
		return result
	}
	return result
}

// WriteToFile write string to a file
func WriteToFile(filename string, data string) (string, error) {
	file, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0644)
	if err != nil {
		return "", err
	}
	defer file.Close()

	_, err = io.WriteString(file, data+"\n")
	if err != nil {
		return "", err
	}
	return filename, file.Sync()
}

// AppendToContent append string to a file
func AppendToContent(filename string, data string) (string, error) {
	// If the file doesn't exist, create it, or append to the file
	f, err := os.OpenFile(filename, os.O_APPEND|os.O_CREATE|os.O_WRONLY, 0644)
	if err != nil {
		return "", err
	}
	if _, err := f.Write([]byte(data + "\n")); err != nil {
		return "", err
	}
	if err := f.Close(); err != nil {
		return "", err
	}
	return filename, nil
}

// FileExists check if file is exist or not
func FileExists(filename string) bool {
	filename = NormalizePath(filename)
	_, err := os.Stat(filename)
	if os.IsNotExist(err) {
		return false
	}
	return true
}

// FolderExists check if file is exist or not
func FolderExists(foldername string) bool {
	foldername = NormalizePath(foldername)
	if _, err := os.Stat(foldername); os.IsNotExist(err) {
		return false
	}
	return true
}

// FileLength count len of file
func FileLength(filename string) int {
	filename = NormalizePath(filename)
	if !FileExists(filename) {
		return 0
	}
	return CountLines(filename)
}

// DirLength count len of file
func DirLength(dir string) int {
	dir = NormalizePath(dir)
	files, err := os.ReadDir(dir)
	if err != nil {
		dir = dir + "/"
		files, err = os.ReadDir(dir)
		if err == nil {
			return len(files)
		}
		return 0
	}
	return len(files)
}

// Copy append content to a file
func Copy(src string, dest string) {
	src = NormalizePath(src)
	dest = NormalizePath(dest)
	if !FileExists(src) || FileLength(src) <= 0 {
		return
	}
	input, _ := os.ReadFile(src)
	os.WriteFile(dest, input, 0644)
}

// GetTS get current timestamp and return a string
func GetTS() string {
	return strconv.FormatInt(time.Now().Unix(), 10)
}

// GenHash gen SHA1 hash from string
func GenHash(text string) string {
	h := sha1.New()
	h.Write([]byte(text))
	hashed := h.Sum(nil)
	return fmt.Sprintf("%x", hashed)
}

// GetFileSize get file size of a file in GB
func GetFileSize(src string) float64 {
	var sizeGB float64
	fi, err := os.Stat(NormalizePath(src))
	if err != nil {
		return sizeGB
	}
	// get the size
	size := fi.Size()
	sizeGB = float64(size) / (1024 * 1024 * 1024)
	return sizeGB
}

// RandomString return a random string with length
func RandomString(n int) string {
	var seededRand = rand.New(rand.NewSource(time.Now().UnixNano()))
	var letter = []rune("abcdefghijklmnopqrstuvwxyz")
	b := make([]rune, n)
	for i := range b {
		b[i] = letter[seededRand.Intn(len(letter))]
	}
	return string(b)
}

// runCmdWithOutput just run os command
func runCmdWithOutput(cmd string) string {
	DebugF("Execute: %s", cmd)
	command := []string{
		"bash",
		"-c",
		cmd,
	}
	realCmd := exec.Command(command[0], command[1:]...)
	// output command output to std too
	output, _ := realCmd.CombinedOutput()
	return string(output)
}

// RunCmdWithOutput run command with timeout
func RunCmdWithOutput(command string, timeoutRaw ...string) string {
	if len(timeoutRaw) == 0 {
		return runCmdWithOutput(command)
	}

	timeout := CalcTimeout(timeoutRaw[0])
	DebugF("Run command with %v seconds timeout", timeout)
	var out string

	c := context.Background()
	deadline := time.Now().Add(time.Duration(timeout) * time.Second)
	c, cancel := context.WithDeadline(c, deadline)
	defer cancel()
	go func() {
		out = RunCmdWithOutput(command)
		cancel()
	}()

	select {
	case <-c.Done():
		return out
	case <-time.After(time.Duration(timeout) * time.Second):
		return out + "\n[err] command got timeout"
	}
}

func runCommandWithError(cmd string) (string, error) {
	DebugF("Execute: %s", cmd)
	command := []string{
		"bash",
		"-c",
		cmd,
	}
	var output string
	realCmd := exec.Command(command[0], command[1:]...)

	// output command output to std too
	cmdReader, _ := realCmd.StdoutPipe()
	errReader, _ := realCmd.StderrPipe()
	scanner := bufio.NewScanner(cmdReader)
	errScanner := bufio.NewScanner(errReader)
	go func() {
		for scanner.Scan() {
			out := scanner.Text()
			DebugF(out)
			output += out + "\n"
		}
	}()
	go func() {
		for errScanner.Scan() {
			DebugF(errScanner.Text())
		}
	}()
	if err := realCmd.Start(); err != nil {
		return output, err
	}
	if err := realCmd.Wait(); err != nil {
		return output, err
	}
	return output, nil
}

// RunCommandWithErr Run a command
func RunCommandWithErr(command string, timeoutRaw ...string) (string, error) {
	if len(timeoutRaw) == 0 {
		return runCommandWithError(command)
	}
	var output string
	var err error

	timeout := CalcTimeout(timeoutRaw[0])
	DebugF("Run command with %v seconds timeout", timeout)
	var out string

	c := context.Background()
	deadline := time.Now().Add(time.Duration(timeout) * time.Second)
	c, cancel := context.WithDeadline(c, deadline)
	defer cancel()
	go func() {
		out, err = runCommandWithError(command)
		cancel()
	}()

	select {
	case <-c.Done():
		return output, err
	case <-time.After(time.Duration(timeout) * time.Second):
		return out, fmt.Errorf("command got timeout")
	}
}

func RunCommandSteamOutput(cmd string) (string, error) {
	DebugF("Execute: %s", cmd)
	command := []string{
		"bash",
		"-c",
		cmd,
	}
	var output string
	realCmd := exec.Command(command[0], command[1:]...)

	// output command output to std too
	cmdReader, _ := realCmd.StdoutPipe()
	errReader, _ := realCmd.StderrPipe()
	scanner := bufio.NewScanner(cmdReader)
	errScanner := bufio.NewScanner(errReader)
	go func() {
		for scanner.Scan() {
			out := scanner.Text()
			fmt.Println(out)
			output += out
		}
	}()
	go func() {
		for errScanner.Scan() {
			DebugF(errScanner.Text())
		}
	}()
	if err := realCmd.Start(); err != nil {
		return output, err
	}
	if err := realCmd.Wait(); err != nil {
		return output, err
	}
	return output, nil
}

func RunOSCommand(cmd string) (string, error) {
	DebugF("Execute: %s", cmd)
	command := []string{
		"bash",
		"-c",
		cmd,
	}
	var output string
	realCmd := exec.Command(command[0], command[1:]...)

	// output command output to std too
	cmdReader, _ := realCmd.StdoutPipe()
	errReader, _ := realCmd.StderrPipe()
	scanner := bufio.NewScanner(cmdReader)
	errScanner := bufio.NewScanner(errReader)
	go func() {
		for scanner.Scan() {
			out := scanner.Text()
			DebugF(out)
			output += out
		}
	}()
	go func() {
		for errScanner.Scan() {
			DebugF(errScanner.Text())
		}
	}()
	if err := realCmd.Start(); err != nil {
		return output, err
	}
	if err := realCmd.Wait(); err != nil {
		return output, err
	}
	return output, nil
}

func RunOSCommandStream(cmd, std string) error {
	DebugF("Execute: %s", cmd)
	command := []string{
		"bash",
		"-c",
		cmd,
	}
	file, _ := os.OpenFile(std, os.O_WRONLY, os.ModeAppend)
	realCmd := exec.Command(command[0], command[1:]...)
	// realCmd.SysProcAttr = &syscall.SysProcAttr{Setpgid: true}

	// output command output to std too
	realCmd.Stdout = file
	realCmd.Stderr = file
	if err := realCmd.Start(); err != nil {
		return err
	}
	if err := realCmd.Wait(); err != nil {
		return err
	}
	return nil
}

// RunCommandWithoutOutput Run a command
func RunCommandWithoutOutput(cmd string) error {
	command := []string{
		"bash",
		"-c",
		cmd,
	}
	DebugF("[Exec] %v", command)
	realCmd := exec.Command(command[0], command[1:]...)
	cmdReader, _ := realCmd.StdoutPipe()
	errReader, _ := realCmd.StderrPipe()
	scanner := bufio.NewScanner(cmdReader)
	errScanner := bufio.NewScanner(errReader)
	go func() {
		for scanner.Scan() {
			InforF(scanner.Text())
		}
	}()
	go func() {
		for errScanner.Scan() {
			DebugF(errScanner.Text())
		}
	}()
	if err := realCmd.Start(); err != nil {
		return err
	}
	if err := realCmd.Wait(); err != nil {
		return err
	}
	return nil
}

// StripPath just Base64 Encode
func StripPath(raw string) string {
	raw = NormalizePath(raw)
	raw = strings.Replace(raw, "/", "_", -1)
	raw = strings.Replace(raw, "..", "_", -1)
	return raw
}

// ZippedFolder zip a folder
func ZippedFolder(src string, dest string) error {
	baseDest := path.Base(dest)
	if FileExists(baseDest) {
		os.RemoveAll(baseDest)
	}
	file, err := os.Create(dest + ".zip")
	if err != nil {
		return err
	}
	defer file.Close()

	w := zip.NewWriter(file)
	defer w.Close()

	walker := func(asbPath string, info os.FileInfo, err error) error {
		if err != nil {
			return err
		}
		if info.IsDir() {
			return nil
		}
		file, err := os.Open(asbPath)
		if err != nil {
			return err
		}
		defer file.Close()
		relPath := strings.Replace(asbPath, src, baseDest, -1)
		f, err := w.Create(relPath)
		if err != nil {
			return err
		}

		_, err = io.Copy(f, file)
		if err != nil {
			return err
		}

		return nil
	}
	err = filepath.Walk(src, walker)
	if err != nil {
		return err
	}
	return nil
}

// CountLines Return the lines amount of the file
func CountLines(filename string) int {
	var amount int
	if strings.HasPrefix(filename, "~") {
		filename, _ = homedir.Expand(filename)
	}
	file, err := os.Open(filename)
	if err != nil {
		return amount
	}
	defer file.Close()

	scanner := bufio.NewScanner(file)
	for scanner.Scan() {
		val := strings.TrimSpace(scanner.Text())
		if val == "" {
			continue
		}
		amount++
	}

	if err := scanner.Err(); err != nil {
		return amount
	}
	return amount
}

// CleanPath get environment variable
func CleanPath(raw string) string {
	var out string
	raw = NormalizePath(raw)
	base := raw
	if FileExists(base) {
		base = filepath.Base(raw)
	}

	if strings.Count(base, "/") > 2 {
		base = base[strings.LastIndex(base, "/")+1:]
		if strings.TrimSpace(base) == "" {
			domain, err := GetDomain(raw)
			if err == nil {
				base = domain
			} else {
				base = RandomString(8)
			}
		}
	}

	out = strings.ReplaceAll(base, "/", "_")
	out = strings.ReplaceAll(out, ":", "_")
	// DebugF("CleanPath: %s -- %s", raw, out)
	return out
}

func IsFile(src string) bool {
	fi, err := os.Stat(NormalizePath(src))
	if err != nil {
		return false
	}
	switch mode := fi.Mode(); {
	case mode.IsDir():
		return false
	case mode.IsRegular():
		if FileLength(src) > 0 {
			return true
		}
		return false
	}
	return false
}

func FolderLength(dir string) int {
	dir = NormalizePath(dir)
	var length int
	if FileExists(dir) {
		dir = path.Dir(dir)
	}
	files, err := os.ReadDir(dir)
	if err != nil {
		return length
	}
	length = len(files)
	return length
}

// ImageAsBase64 read image file as a string
func ImageAsBase64(src string) string {
	src = NormalizePath(src)
	f, err := os.Open(src)
	if err != nil {
		ErrorF("File not found: %v", src)
		return ""
	}

	// Read entire JPG into byte slice.
	reader := bufio.NewReader(f)
	content, err := io.ReadAll(reader)
	if err != nil {
		return ""
	}
	// Encode as base64.
	encoded := base64.StdEncoding.EncodeToString(content)
	return encoded
}

// Base64Encode read image file as a string
func Base64Encode(raw string) string {
	return base64.StdEncoding.EncodeToString([]byte(raw))
}

const bufSize = 1024

// OffsetRange represents a content block of a file.
type OffsetRange struct {
	File  string
	Start int64
	Stop  int64
}

// SplitLineChunks splits file into chunks.
// The whole line are guaranteed to be split in the same chunk.
func SplitLineChunks(filename string, chunks int) ([]OffsetRange, error) {
	info, err := os.Stat(filename)
	if err != nil {
		return nil, err
	}

	if chunks <= 1 {
		return []OffsetRange{
			{
				File:  filename,
				Start: 0,
				Stop:  info.Size(),
			},
		}, nil
	}

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

	var ranges []OffsetRange
	var offset int64
	// avoid the last chunk too few bytes
	preferSize := info.Size()/int64(chunks) + 1
	for {
		if offset+preferSize >= info.Size() {
			ranges = append(ranges, OffsetRange{
				File:  filename,
				Start: offset,
				Stop:  info.Size(),
			})
			break
		}

		offsetRange, err := nextRange(file, offset, offset+preferSize)
		if err != nil {
			return nil, err
		}

		ranges = append(ranges, offsetRange)
		if offsetRange.Stop < info.Size() {
			offset = offsetRange.Stop
		} else {
			break
		}
	}

	return ranges, nil
}

func nextRange(file *os.File, start, stop int64) (OffsetRange, error) {
	offset, err := skipPartialLine(file, stop)
	if err != nil {
		return OffsetRange{}, err
	}

	return OffsetRange{
		File:  file.Name(),
		Start: start,
		Stop:  offset,
	}, nil
}

func skipPartialLine(file *os.File, offset int64) (int64, error) {
	for {
		skipBuf := make([]byte, bufSize)
		n, err := file.ReadAt(skipBuf, offset)
		if err != nil && err != io.EOF {
			return 0, err
		}
		if n == 0 {
			return 0, io.EOF
		}

		for i := 0; i < n; i++ {
			if skipBuf[i] != '\r' && skipBuf[i] != '\n' {
				offset++
			} else {
				for ; i < n; i++ {
					if skipBuf[i] == '\r' || skipBuf[i] == '\n' {
						offset++
					} else {
						return offset, nil
					}
				}
				return offset, nil
			}
		}
	}
}

// A RangeReader is used to read a range of content from a file.
type RangeReader struct {
	file  *os.File
	start int64
	stop  int64
}

// NewRangeReader returns a RangeReader, which will read the range of content from file.
func NewRangeReader(file *os.File, start, stop int64) *RangeReader {
	return &RangeReader{
		file:  file,
		start: start,
		stop:  stop,
	}
}

// Read reads the range of content into p.
func (rr *RangeReader) Read(p []byte) (n int, err error) {
	stat, err := rr.file.Stat()
	if err != nil {
		return 0, err
	}

	if rr.stop < rr.start || rr.start >= stat.Size() {
		return 0, fmt.Errorf("exceed file size")
	}

	if rr.stop-rr.start < int64(len(p)) {
		p = p[:rr.stop-rr.start]
	}

	n, err = rr.file.ReadAt(p, rr.start)
	if err != nil {
		return n, err
	}

	rr.start += int64(n)
	return
}

func Move(src string, dest string) error {
	src = NormalizePath(src)
	if !IsFile(src) && DirLength(src) == 0 {
		return fmt.Errorf("source does not exist: %v", src)
	}

	dest = NormalizePath(dest)
	os.RemoveAll(dest)
	DebugF("Moving %v --> %v", src, dest)
	return os.Rename(src, dest)
}

func IsWritable(filename string) (isWritable bool, err error) {
	isWritable = false
	info, err := os.Stat(filename)
	if err != nil {
		return
	}

	err = nil
	if !info.IsDir() {
		return
	}

	// Check if the user write bit is enabled in file permission
	if info.Mode().Perm()&0200 == 0 {
		return
	}

	isWritable = true
	return
}

// RenderText resolve template from signature file
func RenderText(format string, data map[string]string) string {
	t := template.Must(template.New("").Parse(format))
	buf := &bytes.Buffer{}
	err := t.Execute(buf, data)
	if err != nil {
		return format
	}
	return buf.String()
}