cluster

type DMap interface {
	// Name returns the name of this distributed map.
	Name() string

	// Get retrieves a value by key. Returns ErrKeyNotFound if not present.
	Get(ctx context.Context, key string) (int64, error)

	// Put stores a value for the given key.
	Put(ctx context.Context, key string, value int64) error

	// Delete removes the specified keys. Returns count of deleted keys.
	Delete(ctx context.Context, keys ...string) (int, error)

	// Scan returns an iterator over keys. Options can filter results.
	Scan(ctx context.Context, opts ...ScanOption) (Iterator, error)
}

type Iterator interface {
	// Next advances the iterator. Returns false when exhausted.
	Next() bool

	// Key returns the current key.
	Key() string

	// Close releases iterator resources.
	Close()
}

type Member struct {
	// Name is the member's identifier (typically host:port).
	Name string

	// Hostname is the OS hostname for human-readable identification.
	// Used by sysdump collection to address nodes.
	Hostname string

	// Coordinator indicates if this member is the cluster coordinator.
	Coordinator bool
}

type Membership interface {
	// Members returns the current list of cluster members.
	Members(ctx context.Context) ([]Member, error)

	// SubscribeEvents returns a subscription for cluster membership events.
	// Events are published when nodes join or leave the cluster.
	SubscribeEvents(ctx context.Context) Subscription
}

type MembershipEventKind string

type Message struct {
	Channel string
	Payload string
}

type PubSub interface {
	// Publish sends a message to a channel. Returns number of subscribers that received it.
	Publish(ctx context.Context, channel string, message string) (int64, error)

	// Subscribe creates a subscription to the specified channels.
	Subscribe(ctx context.Context, channels ...string) Subscription
}

type ScanOption func(*ScanOptions)

type ScanOptions struct {
	// Pattern is a regex pattern for key matching.
	Pattern string
}

type Store interface {
	// NewDMap creates or retrieves a distributed map by name.
	NewDMap(name string) (DMap, error)

	// PubSub returns the pub/sub interface for this cluster.
	PubSub() PubSub

	// Membership returns the cluster membership interface.
	Membership() Membership

	// Close shuts down the store and releases resources.
	Close(ctx context.Context) error
}

type Subscription interface {
	// Channel returns a channel that receives messages.
	Channel() <-chan Message

	// Close terminates the subscription.
	Close() error
}