package sutron

import (
	"fmt"
)

type SutronB struct {
	Block   byte
	Group   byte
	Delta   byte
	Data    []byte
	Voltage byte
}

func (s SutronB) GroupString() string {
	switch s.Group {
	case '1':
		return "Scheduled Transmission"
	case '2':
		return "Alarm Transmission"
	case '3':
		return "Forced Transmission"
	default:
		return ""
	}
}

func ParseSutronB(raw []byte) (*SutronB, error) {
	raw_len := len(raw)
	if raw_len < 5 {
		return nil, fmt.Errorf("message structure too short: %d bytes",
			len(raw))
	}

	if raw[0] != 'B' {
		return nil, fmt.Errorf("wrong sutron format: %s", raw[0])
	}

	data := SutronB{}
	data.Block = raw[0]
	data.Group = raw[1]
	data.Delta = raw[2]
	data.Data = raw[3 : raw_len-1]
	data.Voltage = raw[raw_len-1]
	return &data, nil
}