fix(utils/utils): use color.Output to handle escape sequence on Windows

[LussacZheng]

This PR focuses on the colorized outputs in Windows CMD and PowerShell.

But I'm not sure if it will break on non-Windows system. I have only tested on my windows and centos.

Issue

annie -v doesn't print the colorized version info correctly in Windows CMD and PowerShell, but other commands such as annie -i works well.

• CMD
  
• PowerShell
  

Reason

• annie -v calls PrintVersion() to print version info:
  https://github.com/iawia002/annie/blob/d0d473ae01e75b83a14066a37ab85da6a1a0f3c0/utils/utils.go#L258-L266

• annie -i calls printStream() to print stream info:
  https://github.com/iawia002/annie/blob/d0d473ae01e75b83a14066a37ab85da6a1a0f3c0/downloader/utils.go#L40-L50

In PrintVersion() , CMD can't handle escape sequence strings provided by cyan/blue.Sprintf() . However, in printStream() , directly using cyan/blue.Printf() works well. That is because the package color invokes fmt.Fprintf(color.Output, format string, a ...interface{}) to print colorized strings:

• https://github.com/fatih/color/blob/v1.7.0/color.go#L224-L229

  // Printf formats according to a format specifier and writes to standard output.
  // It returns the number of bytes written and any write error encountered.
  // This is the standard fmt.Printf() method wrapped with the given color.
  func (c *Color) Printf(format string, a ...interface{}) (n int, err error) {
  	c.Set()
  	defer c.unset()
  
  	return fmt.Fprintf(Output, format, a...)
  }

• https://github.com/fatih/color/blob/v1.7.0/color.go#L25

  // Output defines the standard output of the print functions. By default
  // os.Stdout is used.
  Output = colorable.NewColorableStdout()

So just use Fprintf with color.Output instead of Printf in PrintVersion():

fmt.Fprintf(
    color.Output,
    "\n%s: version %s, A fast, simple and clean video downloader.\n\n",
    cyan.Sprintf("annie"),
    blue.Sprintf(config.VERSION),
) `

And similar issue to printError():
https://github.com/iawia002/annie/blob/d0d473ae01e75b83a14066a37ab85da6a1a0f3c0/main.go#L195-L200

Intuitive test

Here are some test codes and screenshots (from CMD):

PrintVersion()

func PrintVersion() {
	blue := color.New(color.FgBlue)
	cyan := color.New(color.FgCyan)

	// New method 1
	fmt.Fprintf(
		color.Output,
		"\n%s: version %s, A fast, simple and clean video downloader.\n\n",
		cyan.Sprintf("annie"),
		blue.Sprintf(config.VERSION),
	)

	// New method 2
	// just like https://github.com/iawia002/annie/blob/d0d473ae01e75b83a14066a37ab85da6a1a0f3c0/request/request.go#L110-L118
	fmt.Println()
	cyan.Printf("annie")
	fmt.Print(": version ")
	blue.Printf(config.VERSION)
	fmt.Println(", A fast, simple and clean video downloader.\n")

	// Original method
	fmt.Printf(
		"\n%s: version %s, A fast, simple and clean video downloader.\n\n",
		cyan.Sprintf("annie"),
		blue.Sprintf(config.VERSION),
	)
}

PrintError()

func printError(url string, err error) {
	// New method 1
	fmt.Fprintf(
		color.Output,
		"Downloading %s error:\n%s\n",
		color.CyanString("%s", url), color.RedString("%v", err),
	)
	fmt.Println()

	// Original method
	fmt.Printf(
		"Downloading %s error:\n%s\n",
		color.CyanString("%s", url), color.RedString("%v", err),
	)
	fmt.Println()
}

Try to download a YouTube video without proxy:

References

1. fatih/color/README.md at v1.7.0
2. colorString() not working on Windows cmd.exe fatih/color#91
3. Windows support golangci/golangci-lint#14

[iawia002]

LGTM, thanks!