ccpaging/nxlog4go

// Copyright (C) 2017, ccpaging <ccpaging@gmail.com>.  All rights reserved.
// Copyright (c) 2016 Uber Technologies, Inc.

package color

import (
    "os"
)

// Color represents a text color.
type Color uint8

// Foreground colors.
const (
    Black Color = iota
    Red
    Green
    Yellow
    Blue
    Magenta
    Cyan
    White
    Gray
    LightRed
    LightGreen
    LightYellow
    LightBlue
    LightMagenta
    LightCyan
    LightWhite
    Reset
)

var colorBytes = map[Color][]byte{
    Black:   []byte("\033[30m"),
    Red:     []byte("\033[31m"),
    Green:   []byte("\033[32m"),
    Yellow:  []byte("\033[33m"),
    Blue:    []byte("\033[34m"),
    Magenta: []byte("\033[35m"),
    Cyan:    []byte("\033[36m"),
    White:   []byte("\033[37m"),

    Gray:         []byte("\033[30;1m"),
    LightRed:     []byte("\033[31;1m"),
    LightGreen:   []byte("\033[32;1m"),
    LightYellow:  []byte("\033[33;1m"),
    LightBlue:    []byte("\033[34;1m"),
    LightMagenta: []byte("\033[35;1m"),
    LightCyan:    []byte("\033[36;1m"),
    LightWhite:   []byte("\033[37;1m"),
    Reset:        []byte("\033[0m"),
}

// IsTerminal return true if current system support ansi color.
func IsTerminal() bool {
    return (os.Getenv("TERM") != "" && os.Getenv("TERM") != "dumb") || os.Getenv("ConEmuANSI") == "ON"
}

// Wrap the coloring to the given bytes and return.
func (c Color) Wrap(s []byte) []byte {
    if b, ok := colorBytes[c]; ok {
        b = append(b, s...)
        b = append(b, colorBytes[Reset]...)
        return b
    }
    return s
}

// Bytes return ANSI color bytes
func (c Color) Bytes() []byte {
    if color, ok := colorBytes[c]; ok {
        return color
    }
    return []byte{}
}