const (
	Unknown = State(iota)
	Created
	Online
	Banned
	Offline
	Destroyed
)

type Config interface {
	DialTimeout() time.Duration
	RequestTimeout() time.Duration
	OperationTimeout() time.Duration
	OperationCancelAfter() time.Duration
	StreamTimeout() time.Duration
	Trace() trace.Driver
	ConnectionTTL() time.Duration
	GrpcDialOptions() []grpc.DialOption
}

type Conn interface {
	grpc.ClientConnInterface

	Endpoint() endpoint.Endpoint
	GetState() State
	SetState(context.Context, State) State
	Close(ctx context.Context) error
	Park(ctx context.Context) error
	TTL() <-chan time.Time
}

type Pessimizer interface {
	Pessimize(ctx context.Context, e endpoint.Endpoint) error
}

type Pool interface {
	closer.Closer
	Pessimizer
	PoolGetter
}

type PoolConfig interface {
	ConnectionTTL() time.Duration
	GrpcDialOptions() []grpc.DialOption
}

type PoolGetter interface {
	GetConn(endpoint endpoint.Endpoint) Conn
}

type PoolGetterCloser interface {
	PoolGetter
	closer.Closer
}

type State int8