package logger

import (
	"log"
	"os"
)

type LoggerInterface interface {
	Tracef(fmt string, args ...interface{})
	Infof(fmt string, args ...interface{})
	Warnf(fmt string, args ...interface{})
	Errorf(fmt string, args ...interface{})
}

// a default implementation of the LoggerInterface, simply using the 'log' library
type LeveledLogger struct {
	level int
}

var std = LeveledLogger{}

var levels = map[string]int{
	"ERROR": 400,
	"WARN" : 300,
	"INFO" : 200,
	"TRACE" : 100,
}

func (l *LeveledLogger) levelPrint(minimumLevel int, fmt string, args ...interface{}) {
	if l.level == 0 { 
		l.level = levels[os.Getenv("LOGLVL")]
		if l.level == 0 { l.level = levels["WARN"] }
	}
	if minimumLevel >= l.level {
		log.Printf(fmt+"\n", args...)
	}
}

func (l *LeveledLogger) Tracef(fmt string, args ...interface{}) {
	l.levelPrint(levels["TRACE"], fmt, args...)
}

func (l *LeveledLogger) Infof(fmt string, args ...interface{}) {
	l.levelPrint(levels["INFO"], fmt, args...)
}
func (l *LeveledLogger) Warnf(fmt string, args ...interface{}) {
	l.levelPrint(levels["WARN"], fmt, args...)
}
func (l *LeveledLogger) Errorf(fmt string, args ...interface{}) {
	l.levelPrint(levels["ERROR"], fmt, args...)
}

func Tracef(fmt string, args ...interface{}) {
	std.levelPrint(levels["TRACE"], fmt, args...)
}

func Infof(fmt string, args ...interface{}) {
	std.levelPrint(levels["INFO"], fmt, args...)
}
func Warnf(fmt string, args ...interface{}) {
	std.levelPrint(levels["WARN"], fmt, args...)
}
func Errorf(fmt string, args ...interface{}) {
	std.levelPrint(levels["ERROR"], fmt, args...)
}