messaging

type AckManager interface {
	// Read an item into backlog for processing for ack
	ReadItem(id int64) error
	// Get current max ID from read items
	GetReadLevel() int64
	// Set current max ID from read items
	SetReadLevel(readLevel int64)
	// Mark an item as done processing, and remove from backlog
	AckItem(id int64) (ackLevel int64)
	// Get current max level that can safely ack
	GetAckLevel() int64
	// Set current max level that can safely ack
	SetAckLevel(ackLevel int64)
	// GetBacklogCount return the of items that are waiting for ack
	GetBacklogCount() int64
}

type Client interface {
	NewConsumer(appName, consumerName string) (Consumer, error)
	NewProducer(appName string) (Producer, error)
}

type CloseableProducer interface {
	Producer
	Close() error
}

type Consumer interface {
	// Start starts the consumer
	Start() error
	// Stop stops the consumer
	Stop()
	// Messages return the message channel for this consumer
	Messages() <-chan Message
}

type Message interface {
	// Value is a mutable reference to the message's value
	Value() []byte
	// Partition is the ID of the partition from which the message was read.
	Partition() int32
	// Offset is the message's offset.
	Offset() int64
	// Ack marks the message as successfully processed.
	Ack() error
	// Nack marks the message processing as failed and the message will be retried or sent to DLQ.
	Nack() error
}

type Producer interface {
	Publish(ctx context.Context, message interface{}) error
}