package storage_ng

import (
	clientmodel "github.com/prometheus/client_golang/model"

	"github.com/prometheus/prometheus/storage/metric"
	"github.com/prometheus/prometheus/utility"
)

type Storage interface {
	// AppendSamples stores a group of new samples. Multiple samples for the same
	// fingerprint need to be submitted in chronological order, from oldest to
	// newest (both in the same call to AppendSamples and across multiple calls).
	AppendSamples(clientmodel.Samples)
	// NewPreloader returns a new Preloader which allows preloading and pinning
	// series data into memory for use within a query.
	NewPreloader() Preloader
	// Get all of the metric fingerprints that are associated with the
	// provided label matchers.
	GetFingerprintsForLabelMatchers(metric.LabelMatchers) clientmodel.Fingerprints
	// Get all of the label values that are associated with a given label name.
	GetLabelValuesForLabelName(clientmodel.LabelName) clientmodel.LabelValues
	// Get the metric associated with the provided fingerprint.
	GetMetricForFingerprint(clientmodel.Fingerprint) clientmodel.Metric
	// Get all label values that are associated with a given label name.
	GetAllValuesForLabel(clientmodel.LabelName) clientmodel.LabelValues
	// Construct an iterator for a given fingerprint.
	NewIterator(clientmodel.Fingerprint) SeriesIterator
	// Run the request-serving and maintenance loop.
	Serve(started chan<- bool)
	// Close the MetricsStorage and releases all resources.
	Close() error
}

type SeriesIterator interface {
	// Get the two values that are immediately adjacent to a given time.
	GetValueAtTime(clientmodel.Timestamp) metric.Values
	// Get the boundary values of an interval: the first value older than
	// the interval start, and the first value younger than the interval
	// end.
	GetBoundaryValues(metric.Interval) metric.Values
	// Get all values contained within a provided interval.
	GetRangeValues(metric.Interval) metric.Values
}

// A Persistence stores samples persistently across restarts.
type Persistence interface {
	// PersistChunk persists a single chunk of a series.
	PersistChunk(clientmodel.Fingerprint, chunk) error
	// PersistIndexes persists a Prometheus server's timeseries indexes. It
	// is the caller's responsibility to not modify indexes while persisting
	// is underway, and to not call this method multiple times concurrently.
	PersistIndexes(i *Indexes) error
	// PersistHeads persists all open (non-full) head chunks.
	PersistHeads(map[clientmodel.Fingerprint]*memorySeries) error

	// DropChunks deletes all chunks from a timeseries whose last sample time is
	// before beforeTime.
	DropChunks(fp clientmodel.Fingerprint, beforeTime clientmodel.Timestamp) error

	// LoadChunks loads a group of chunks of a timeseries by their index. The
	// chunk with the earliest time will have index 0, the following ones will
	// have incrementally larger indexes.
	LoadChunks(fp clientmodel.Fingerprint, indexes []int) (chunks, error)
	// LoadChunkDescs loads chunkDescs for a series up until a given time.
	LoadChunkDescs(fp clientmodel.Fingerprint, beforeTime clientmodel.Timestamp) (chunkDescs, error)
	// LoadHeads loads all open (non-full) head chunks.
	LoadHeads(map[clientmodel.Fingerprint]*memorySeries) error
	// LoadIndexes loads and returns all timeseries indexes. It is the
	// caller's responsibility to not modify indexes while loading is
	// underway, and to not call this method multiple times concurrently.
	LoadIndexes() (*Indexes, error)
}

// A Preloader preloads series data necessary for a query into memory and pins
// them until released via Close().
type Preloader interface {
	PreloadRange(fp clientmodel.Fingerprint, from clientmodel.Timestamp, through clientmodel.Timestamp) error
	/*
		// GetMetricAtTime loads and pins samples around a given time.
		GetMetricAtTime(clientmodel.Fingerprint, clientmodel.Timestamp) error
		// GetMetricAtInterval loads and pins samples at intervals.
		GetMetricAtInterval(fp clientmodel.Fingerprint, from, through clientmodel.Timestamp, interval time.Duration) error
		// GetMetricRange loads and pins a given range of samples.
		GetMetricRange(fp clientmodel.Fingerprint, from, through clientmodel.Timestamp) error
		// GetMetricRangeAtInterval loads and pins sample ranges at intervals.
		GetMetricRangeAtInterval(fp clientmodel.Fingerprint, from, through clientmodel.Timestamp, interval, rangeDuration time.Duration) error
	*/
	// Close unpins any previously requested series data from memory.
	Close()
}

type Closer interface {
	// Close cleans up any used resources.
	Close()
}

type Indexes struct {
	FingerprintToSeries     map[clientmodel.Fingerprint]*memorySeries
	LabelPairToFingerprints map[metric.LabelPair]utility.Set
	LabelNameToLabelValues  map[clientmodel.LabelName]utility.Set
}