package ll

// MsgType of the lowlevel message
type MsgType uint8

// Msg holds a lowlevel message including data payload
type Msg struct {
	Type MsgType
	Data []byte
}

// Lowlevel message type constants
const (
	MsgTypeUnknown    MsgType = 0x00 // Unknown message
	MsgTypeHsRequest  MsgType = 0x01 // Handshake request message
	MsgTypeReply      MsgType = 0x02 // Reply message
	MsgTypeRegister   MsgType = 0x03 // Register message
	MsgTypeUnregister MsgType = 0x04 // Unregister message
	MsgTypePlain      MsgType = 0x10 // Plain message
	MsgTypeEncrypted  MsgType = 0x20 // Encrypted message
	MsgTypeTime       MsgType = 0x40 // DI-Net time message
)

func (t MsgType) String() string {
	switch t {
	case MsgTypeHsRequest:
		return "DNP_HS_REQUEST"
	case MsgTypeReply:
		return "DNP_REPLY"
	case MsgTypePlain:
		return "DNP_PLAIN"
	case MsgTypeRegister:
		return "DNP_REGISTER"
	case MsgTypeUnregister:
		return "DNP_UNREGISTER"
	case MsgTypeEncrypted:
		return "DNP_ENCRYPTED"
	case MsgTypeTime:
		return "DNP_TIME"
	}
	return "unknown"
}

// Valid checks if the message type is valid
func (t MsgType) Valid() bool {
	switch t {
	case MsgTypeHsRequest, MsgTypeReply, MsgTypePlain, MsgTypeEncrypted,
		MsgTypeTime, MsgTypeRegister, MsgTypeUnregister:
		return true
	}
	return false
}

// IsReplySuccess checks if a low-level message is a reply and OK
func (m *Msg) IsReplySuccess() bool {
	return m.Type == MsgTypeReply && string(m.Data) == "MKAY"
}

// IsReplyError checks if a low-level message is a reply and not OK
func (m *Msg) IsReplyError() bool {
	return m.Type == MsgTypeReply && string(m.Data) == "WTF"
}