package subscribe

import "fmt"

type ChannelExistError struct {
	Channel string
}

// Error returns the formatted configuration error.
func (cee ChannelExistError) Error() string {
	return fmt.Sprintf("Subscriber: Channel[%q] is already subscribed.", cee.Channel)
}

type ChannelIsNotExistError struct {
	Channel string
}

// Error returns the formatted configuration error.
func (cinee ChannelIsNotExistError) Error() string {
	return fmt.Sprintf("Subscriber: Channel[%q] is not subscribed.", cinee.Channel)
}

type Subscriber interface {
	Start() error
	Stop() error

	Subscribe(channel string) (<-chan *Message, error)
	Unsubscribe(channel string) error
}