broker

type DeliveryReliability int32

type ErrorHandler = generic.DelegateAction1[error] // 错误处理器

type EventHandler = generic.DelegateFunc1[IEvent, error]

type IBroker interface {
	// Publish the data argument to the given topic. The data argument is left untouched and needs to be correctly interpreted on the receiver.
	Publish(ctx context.Context, topic string, data []byte) error
	// Subscribe will express interest in the given topic pattern. Use option EventHandler to handle message events.
	Subscribe(ctx context.Context, pattern string, settings ...option.Setting[SubscriberOptions]) (ISubscriber, error)
	// SubscribeSync will express interest in the given topic pattern.
	SubscribeSync(ctx context.Context, pattern string, settings ...option.Setting[SubscriberOptions]) (ISyncSubscriber, error)
	// SubscribeChan will express interest in the given topic pattern.
	SubscribeChan(ctx context.Context, pattern string, settings ...option.Setting[SubscriberOptions]) (IChanSubscriber, error)
	// Flush will perform a round trip to the server and return when it receives the internal reply.
	Flush(ctx context.Context) error
	// GetDeliveryReliability return message delivery reliability.
	GetDeliveryReliability() DeliveryReliability
	// GetMaxPayload return max payload bytes.
	GetMaxPayload() int64
	// GetSeparator return topic path separator.
	GetSeparator() string
}

type IChanSubscriber interface {
	ISubscriber
	// EventChan returns a channel that can be used to receive events from the subscriber.
	EventChan() (<-chan IEvent, error)
}

type IEvent interface {
	// Pattern returns the subscription pattern used to create the event subscriber.
	Pattern() string
	// Topic returns the topic the event was received on.
	Topic() string
	// Queue subscribers with the same queue name will create a shared subscription where each receives a subset of messages.
	Queue() string
	// Message returns the raw message payload of the event.
	Message() []byte
	// Ack acknowledges the successful processing of the event. It indicates that the event can be removed from the subscription queue.
	Ack(ctx context.Context) error
	// Nak negatively acknowledges a message. This tells the server to redeliver the message.
	Nak(ctx context.Context) error
}

type ISubscriber interface {
	context.Context
	// Pattern returns the subscription pattern used to create the subscriber.
	Pattern() string
	// Queue subscribers with the same queue name will create a shared subscription where each receives a subset of messages.
	Queue() string
	// Unsubscribe unsubscribes the subscriber from the topic.
	Unsubscribe() <-chan struct{}
}

type ISyncSubscriber interface {
	ISubscriber
	// Next is a blocking call that waits for the next event to be received from the subscriber.
	Next() (IEvent, error)
}

type SubscriberOptions struct {
	// AutoAck defaults to true. When a handler returns with a nil error the message is acked.
	AutoAck bool
	// Queue subscribers with the same queue name will create a shared subscription where each receives a subset of messages.
	Queue string
	// EventHandler is the function that will be called to handle the received events.
	EventHandler EventHandler
	// EventChanSize specifies the size of the event channel used for received synchronously event.
	EventChanSize int
	// UnsubscribedCB Unsubscribed callback method.
	UnsubscribedCB UnsubscribedCB
}

type UnsubscribedCB = generic.DelegateAction1[ISubscriber]