api

type RemoteEndpoints interface {
	// Engines returns remote engines.
	//
	// If mint and/or maxt of the query is unknown, the caller must pass
	// math.MinInt64 and math.MaxInt64 respectively to retrieve unpruned engines.
	Engines(mint, maxt int64) []RemoteEngine
}

type RemoteEngine interface {
	MaxT() int64
	MinT() int64

	// The external labels of the remote engine. These are used to limit fanout. The engine uses these to
	// not distribute into remote engines that would return empty responses because their labelset is not matching.
	LabelSets() []labels.Labels

	// The external labels of the remote engine that form a logical partition. This is expected to be
	// a subset of the result of "LabelSets()". The engine uses these to compute how to distribute a query.
	// It is important that, for a given set of remote engines, these labels do not overlap meaningfully.
	PartitionLabelSets() []labels.Labels

	NewRangeQuery(ctx context.Context, opts promql.QueryOpts, plan RemoteQuery, start, end time.Time, interval time.Duration) (promql.Query, error)
}

type RemoteQuery interface {
	fmt.Stringer
}