rangedb

type AggregateMessage interface {
	AggregateID() string
	AggregateType() string
}

type Event interface {
	AggregateMessage
	EventType() string
}

type EventBinder interface {
	Bind(events ...Event)
}

type EventRecord struct {
	Event    Event
	Metadata interface{}
}

type EventTypeIdentifier interface {
	EventTypeLookup(eventTypeName string) (reflect.Type, bool)
}

type Record struct {
	AggregateType        string      `msgpack:"a" json:"aggregateType"`
	AggregateID          string      `msgpack:"i" json:"aggregateID"`
	GlobalSequenceNumber uint64      `msgpack:"g" json:"globalSequenceNumber"`
	StreamSequenceNumber uint64      `msgpack:"s" json:"streamSequenceNumber"`
	InsertTimestamp      uint64      `msgpack:"u" json:"insertTimestamp"`
	EventID              string      `msgpack:"e" json:"eventID"`
	EventType            string      `msgpack:"t" json:"eventType"`
	Data                 interface{} `msgpack:"d" json:"data"`
	Metadata             interface{} `msgpack:"m" json:"metadata"`
}

type RecordIoStream interface {
	Read(io.Reader) RecordIterator
	Write(io.Writer, RecordIterator) <-chan error
	Bind(events ...Event)
}

type RecordIterator interface {
	Next() bool
	Record() *Record
	Err() error
}

type RecordSerializer interface {
	Serialize(record *Record) ([]byte, error)
	Deserialize(data []byte) (*Record, error)
	Bind(events ...Event)
}

type RecordSubscriber interface {
	Accept(record *Record)
}

type RecordSubscriberFunc func(*Record)

type RecordSubscription interface {
	// Start returns immediately after subscribing only to new events in a goroutine.
	Start() error

	// StartFrom blocks until all previous events have been processed, then returns after subscribing to new events in a goroutine.
	StartFrom(globalSequenceNumber uint64) error

	// Stop cancels the subscription and stops.
	Stop()
}

type ResultRecord struct {
	Record *Record
	Err    error
}

type Store interface {
	EventBinder

	// Events returns a RecordIterator containing all events in the store starting with globalSequenceNumber.
	Events(ctx context.Context, globalSequenceNumber uint64) RecordIterator

	// EventsByAggregateTypes returns a RecordIterator containing all events for each aggregateType(s) starting
	// with globalSequenceNumber.
	EventsByAggregateTypes(ctx context.Context, globalSequenceNumber uint64, aggregateTypes ...string) RecordIterator

	// EventsByStream returns a RecordIterator containing all events in the stream starting with streamSequenceNumber.
	EventsByStream(ctx context.Context, streamSequenceNumber uint64, streamName string) RecordIterator

	// OptimisticDeleteStream removes an entire stream. If the expectedStreamSequenceNumber does not match the current
	// stream sequence number, an rangedberror.UnexpectedSequenceNumber error is returned.
	OptimisticDeleteStream(ctx context.Context, expectedStreamSequenceNumber uint64, streamName string) error

	// OptimisticSave persists events to a single stream returning the new StreamSequenceNumber or an error. If
	// the expectedStreamSequenceNumber does not match the current stream sequence number,
	// an rangedberror.UnexpectedSequenceNumber error is returned.
	OptimisticSave(ctx context.Context, expectedStreamSequenceNumber uint64, eventRecords ...*EventRecord) (uint64, error)

	// Save persists events to a single stream returning the new StreamSequenceNumber or an error.
	Save(ctx context.Context, eventRecords ...*EventRecord) (uint64, error)

	AllEventsSubscription(ctx context.Context, bufferSize int, subscriber RecordSubscriber) RecordSubscription
	AggregateTypesSubscription(ctx context.Context, bufferSize int, subscriber RecordSubscriber, aggregateTypes ...string) RecordSubscription
	TotalEventsInStream(ctx context.Context, streamName string) (uint64, error)
}