logger_internal.go

package log

import (
	"fmt"
	"io"
	"os"
	"runtime"
	"strings"
	"sync"
	"time"

	"github.com/fatih/color"
)

var colors = map[string]*color.Color{
	"DEBUG": color.New(color.FgHiBlack),
	"INFO ": color.New(color.FgHiGreen),
	"WARN ": color.New(color.FgHiYellow),
	"ERROR": color.New(color.FgHiRed),
	"FATAL": color.New(color.FgHiRed),
}

var mutex sync.Mutex

func init() {

	TimeZone, _ = time.LoadLocation("Europe/Brussels")
	DebugMode = os.Getenv("DEBUG") == "1"
	PrintTimestamp = os.Getenv("PRINT_TIMESTAMP") == "1"

	color.NoColor = false

}

func formatMessage(args ...interface{}) string {
	msg := fmt.Sprintln(args...)
	msg = strings.TrimRight(msg, " \n\r")
	return msg
}

func formatSeparator(message string, separator string, length int) string {
	if message == "" {
		return strings.Repeat(separator, length)
	}
	prefix := strings.Repeat(separator, 4)
	suffixLength := length - len(message) - len(prefix) - 4
	suffix := ""
	if suffixLength > 0 {
		suffix = strings.Repeat(separator, suffixLength)
	}
	return prefix + "[ " + message + " ]" + suffix
}

func printMessage(level string, message string) {

	level = strings.ToUpper(level)

	if PrintTimestamp {
		message = addTimestampToMessage(level, message)
	}

	if PrintColors && runtime.GOOS != "windows" {
		lines := splitInLines(message)
		for _, line := range lines {
			printColoredMessage(level, line)
		}
	} else {
		printNonColoredMessage(level, message)
	}

}

func printNonColoredMessage(level string, message string) {
	w := writerForLevel(level)
	w.Write([]byte(message + "\n"))
}

func printColoredMessage(level string, message string) {
	w := writerForLevel(level)
	if c, ok := colors[level]; ok {
		mutex.Lock()
		defer mutex.Unlock()
		c.EnableColor()
		c.Fprint(w, message)
		w.Write([]byte("\n"))
	}
}

func addTimestampToMessage(level string, message string) string {

	tstamp := time.Now()
	if TimeZone != nil {
		tstamp = tstamp.In(TimeZone)
	}

	formattedTime := tstamp.Format(TimeFormat)
	message = formattedTime + " | " + level + " | " + message

	return message

}

func writerForLevel(level string) io.Writer {
	if level == "ERROR" || level == "FATAL" {
		return Stderr
	}
	return Stdout
}

func splitInLines(text string) []string {
	text = strings.Replace(text, "\r\n", "\n", -1)
	text = strings.Replace(text, "\r", "\n", -1)
	lines := strings.Split(text, "\n")
	return lines
}