package protocol

import (
	"encoding/json"
	"errors"
)

type ControlMessage struct {
	Type   MessageType `json:"type"`
	Topic  Topic       `json:"topic,omitempty"`
	Topics []Topic     `json:"topics,omitempty"`
}

type BroadcastMessage struct {
	Type      MessageType     `json:"type"`
	Topic     Topic           `json:"topic"`
	Payload   json.RawMessage `json:"payload"`
	Timestamp int64           `json:"timestamp"`
}

func (m ControlMessage) Validate() error {
	switch m.Type {
	case MsgInit:
		if len(m.Topics) == 0 {
			return errors.New("init requires topics")
		}
	case MsgSubscribe:
		if m.Topic == "" {
			return errors.New("subscribe requires topic")
		}
	default:
		return errors.New("unknown message type")
	}
	return nil
}

var (
	ErrInvalidMessage  = errors.New("invalid message")
	ErrPolicyViolation = errors.New("policy violation")
)