log

type CallerInfo struct {
	FileName string
	FilePath string
	FuncName string
	LineNo   int
}

type Config struct {
	// Name is a logger's identificator used to instantiate a proper logger type
	// from a config.
	Name string

	// Severity indicates the minimum severity a logger will be logging messages at.
	Severity string
}

type LogWriter interface {
	Infof(format string, args ...interface{})
	Warningf(format string, args ...interface{})
	Errorf(format string, args ...interface{})
}

type Logger interface {
	// Writer returns logger's underlying io.Writer used to write log messages to.
	//
	// It may be, for example, the standard output for a console logger or a socket
	// connection for a UDP logger.
	//
	// Should return `nil` if the logger is not supposed to log at the specified severity.
	Writer(Severity) io.Writer

	// FormatMessage constructs and returns a final message that will go to the logger's
	// output channel.
	FormatMessage(Severity, *CallerInfo, string, ...interface{}) string

	// Sets a loggers current Severity level.
	SetSeverity(Severity)

	// Gets the current Severity level.
	GetSeverity() Severity
}

type Severity int32