observer/pkg/level/level.go

package level

import (
	"strings"

	"git.ma-al.com/maal-libraries/observer/pkg/syslog"
	"go.opentelemetry.io/otel/attribute"
)

type SeverityLevel uint8

const (
	// A magical zero value.
	// WARN: DO NOT USE IN LOGS OR BASICALLY EVER
	unset SeverityLevel = iota
	// This event requires an immediate action. If you suspect that occurence of an event may signal that the
	// data will get lost, corrupted, or that the application will change its behaviour following the event in
	// an undesired way, select the ALERT level.
	ALERT
	// A critical error has occured. Critical errors are such which can be tough to fix or made the users
	// experience significantly worse but unlike errors that trigger ALERT they can be fixed at any moment.
	CRIT
	// An error has occured but it is not expected to cause any serious issues. These will be often
	// `Internal Server Error` responses from an HTTP server.
	ERR
	// Signals that something suspicious has happened, for example, a query took too long to execute, gaining access
	// to a resource took multiple attempts, a conflict was automatically resolved, etc.
	WARN
	// Used to inform about standard, expected events of an application, like creation of a new object or a new
	// log-in from a user. Information that could be:
	// - used to audit the application,
	// - resolve customer's complaints,
	// - track history of significant changes,
	// - calculate valuable statistics;
	// should be collected and logged at this level.
	INFO
	// Verbose information that is useful and meaningful to application developers and system administrators.
	DEBUG
	// Extremely verbose information that can be used to investigate performance of specific parts of an application.
	// It is transled to [syslog.DEBUG] by [IntoSyslogLevel].
	TRACE
)

func (l SeverityLevel) String() string {
	switch l {
	case ALERT:
		return "ALERT"
	case CRIT:
		return "CRIT"
	case ERR:
		return "ERR"
	case WARN:
		return "WARN"
	case INFO:
		return "INFO"
	case DEBUG:
		return "DEBUG"
	case TRACE:
		return "TRACE"
	default:
		return "CRIT"
	}
}

func FromString(level string) SeverityLevel {
	level = strings.ToLower(level)
	switch level {
	case "alert":
		return ALERT
	case "crit", "critical":
		return CRIT
	case "err", "error":
		return ERR
	case "warn", "warning":
		return WARN
	case "info":
		return INFO
	case "debug":
		return DEBUG
	case "trace":
		return TRACE
	default:
		return unset
	}
}

func (lvl SeverityLevel) IntoTraceAttribute() attribute.KeyValue {
	return attribute.String("level", lvl.String())
}

func (lvl SeverityLevel) IntoSyslogLevel() syslog.SyslogLevel {
	switch lvl {
	case ALERT:
		return syslog.ALERT
	case CRIT:
		return syslog.CRIT
	case ERR:
		return syslog.ERR
	case WARN:
		return syslog.WARNING
	case INFO:
		return syslog.INFO
	case DEBUG:
		return syslog.DEBUG
	case TRACE:
		return syslog.DEBUG
	default:
		return syslog.EMERG
	}
}