package identity

import (
	"bytes"
	"errors"

	"github.com/simple-rules/harmony-benchmark/proto"
)

// the number of bytes consensus message type occupies
const IDENTITY_MESSAGE_TYPE_BYTES = 1

type IdentityMessageType byte

const (
	IDENTITY IdentityMessageType = iota
	// TODO: add more types
)

type MessageType int

const (
	REGISTER MessageType = iota
	ANNOUNCE
)

// Returns string name for the MessageType enum
func (msgType MessageType) String() string {
	names := [...]string{
		"REGISTER",
		"ANNOUNCE",
	}

	if msgType < REGISTER || msgType > ANNOUNCE {
		return "Unknown"
	}
	return names[msgType]
}

// GetIdentityMessageType Get the consensus message type from the identity message
func GetIdentityMessageType(message []byte) (MessageType, error) {
	if len(message) < 1 {
		return 0, errors.New("Failed to get identity message type: no data available.")
	}
	return MessageType(message[0]), nil
}

// GetIdentityMessagePayload message payload from the identity message
func GetIdentityMessagePayload(message []byte) ([]byte, error) {
	if len(message) < 2 {
		return []byte{}, errors.New("Failed to get identity message payload: no data available.")
	}
	return message[IDENTITY_MESSAGE_TYPE_BYTES:], nil
}

// Concatenate msgType as one byte with payload, and return the whole byte array
func ConstructIdentityMessage(identityMessageType MessageType, payload []byte) []byte {
	byteBuffer := bytes.NewBuffer([]byte{byte(proto.IDENTITY)})
	byteBuffer.WriteByte(byte(IDENTITY))
	byteBuffer.WriteByte(byte(identityMessageType))
	byteBuffer.Write(payload)
	return byteBuffer.Bytes()
}