package logging

import (
	"fmt"
	"strings"
)

type LogLevel int
const (
	LevelDebug LogLevel = iota
	LevelInfo
	LevelWarn
	LevelError
	LevelFatal
)

func (l LogLevel) String() string {
	str, _ := levelString[l]
	return str
}

func (l LogLevel) MarshalJSON() ([]byte, error) {
	return []byte(`"` + l.String() + `"`), nil
}

func (l *LogLevel) UnmarshalJSON(data []byte) error {
	level_string := strings.Trim(string(data), `"`)
  for key, val := range levelString {
		if val == level_string {
			*l = key
		return nil
		}
	}
	return fmt.Errorf("Logging : ERROR : LogLevel(%s) is not a valid level", level_string)
}

var levelString = map[LogLevel]string {
	LevelDebug: "DEBUG",
	LevelInfo: "INFO",
	LevelWarn: "WARN",
	LevelError: "ERROR",
	LevelFatal: "FATAL",
}

var minLevel = LevelInfo
var maxLevel = LevelFatal

func SetMaxLogLevel(level LogLevel) error {

	if _, exist := levelString[level]; ! exist {
		return fmt.Errorf("Logger : ERROR : Level with value %d does not exist", level)
	}

	if level < minLevel {
		return fmt.Errorf("Logger : ERROR : Cannot set your Max LogLevel (%s) to be lower than the current Min (%s)", level, minLevel)
	}
	maxLevel = level
	return nil
}

func SetMinLogLevel(level LogLevel) error {
	if _, exist := levelString[level]; ! exist {
		return fmt.Errorf("Logger : ERROR : Level with value %d does not exist", level)
	}

	if level > maxLevel {
		return fmt.Errorf("Logger : ERROR : Cannot set your Min LogLevel (%s) to be greater than the current Max (%s)", level, maxLevel)
	}

	minLevel = level

	return nil
}