abzcoding/hget

package main

import (
    "fmt"
    "io"
    "os"

    "github.com/fatih/color"
    "github.com/mattn/go-colorable"
    "github.com/mattn/go-isatty"
)

var (
    Stdout     = colorable.NewColorableStdout()
    Stderr     = colorable.NewColorableStderr()
    Default UI = Console{Stdout: Stdout, Stderr: Stderr}
)

// UI represents a simple IO output.
type UI interface {
    Printf(format string, a ...interface{}) (n int, err error)
    Println(a ...interface{}) (n int, err error)
    Errorf(format string, a ...interface{}) (n int, err error)
    Errorln(a ...interface{}) (n int, err error)
}

// Printf outputs information level logs
func Printf(format string, a ...interface{}) (n int, err error) {
    return Default.Printf(color.CyanString("INFO: ")+format, a...)
}

// Errorf outputs error level logs
func Errorf(format string, a ...interface{}) (n int, err error) {
    return Default.Errorf(color.RedString("ERROR: ")+format, a...)
}

// Warnf outputs warning level logs
func Warnf(format string, a ...interface{}) (n int, err error) {
    return Default.Errorf(color.YellowString("WARN: ")+format, a...)
}

// Errorln is non formatted error printer.
func Errorln(a ...interface{}) (n int, err error) {
    return Default.Errorln(a...)
}

// IsTerminal checks if we have tty
func IsTerminal(f *os.File) bool {
    return isatty.IsTerminal(f.Fd())
}

// Console is an implementation of UI interface
type Console struct {
    Stdout io.Writer
    Stderr io.Writer
}

// Printf prints formatted information logs to Stdout
func (c Console) Printf(format string, a ...interface{}) (n int, err error) {
    return fmt.Fprintf(c.Stdout, format, a...)
}

// Println prints information logs to Stdout
func (c Console) Println(a ...interface{}) (n int, err error) {
    return fmt.Fprintln(c.Stdout, a...)
}

// Errorf prints formatted error logs to Stderr
func (c Console) Errorf(format string, a ...interface{}) (n int, err error) {
    return fmt.Fprintf(c.Stderr, format, a...)
}

// Errorln prints error logs to Stderr
func (c Console) Errorln(a ...interface{}) (n int, err error) {
    return fmt.Fprintln(c.Stderr, a...)
}