stats

type ArchiveRecord struct {
	Key      string `json:"key"`      // e.g. "pv:2026-08-18:/home"
	Type     string `json:"type"`     // "counter", "gauge", "set", "hll", "timer"
	Value    any    `json:"value"`    // type-specific value (int64, uint64, TimerSummary, etc.)
	Date     string `json:"date"`     // extracted "YYYY-MM-DD"
	Archived string `json:"archived"` // ISO timestamp of when it was archived
}

type ArchiveStore interface {
	// Save persists a single expired key's value.
	// If the key already exists in the archive, it should be upserted
	// (replaced with the new value).
	Save(record ArchiveRecord) error

	// Query retrieves archived records by date range (inclusive).
	// dateFrom and dateTo are "YYYY-MM-DD" format.
	// Returns records ordered by date, then key.
	Query(dateFrom, dateTo string) ([]ArchiveRecord, error)

	// QueryByType retrieves archived records by type and date range.
	QueryByType(entryType, dateFrom, dateTo string) ([]ArchiveRecord, error)

	// Close releases resources held by the store.
	Close() error
}

type Collector interface {
	// Counter returns a Counter primitive for the given key.
	// Multiple calls with the same key return the same logical counter.
	Counter(key string) Counter

	// Gauge returns a Gauge primitive for the given key.
	Gauge(key string) Gauge

	// Set returns a Set primitive for exact deduplication.
	// Use for small cardinalities (e.g. retention sets up to ~100K).
	Set(key string) Set

	// HLL returns a HyperLogLog primitive for probabilistic deduplication.
	// Use for large cardinalities (UV, IP, DAU). Memory: ~12 KB per key.
	HLL(key string) HLL

	// Timer returns a Timer primitive for latency tracking.
	Timer(key string) Timer

	// Flush persists in-memory state to the underlying store (if applicable).
	// For Redis, this is a no-op. For file/memory, it writes to disk.
	Flush() error

	// Close releases any resources held by the collector.
	Close() error
}

type Counter interface {
	// Incr increments by 1.
	Incr() int64

	// IncrBy increments by delta and returns the new value.
	IncrBy(delta int64) int64

	// Get returns the current count.
	Get() int64

	// Reset sets the counter to 0.
	Reset() error
}

type Gauge interface {
	// Set sets the gauge to value.
	Set(value int64)

	// Incr increments the gauge by 1.
	Incr() int64

	// Decr decrements the gauge by 1.
	Decr() int64

	// Get returns the current value.
	Get() int64
}

type HLL interface {
	// Add inserts an element into the sketch.
	Add(element string)

	// Estimate returns the estimated cardinality.
	Estimate() uint64

	// Merge merges another HLL into this one.
	Merge(other HLL) error

	// Reset clears the sketch.
	Reset() error
}

type Set interface {
	// Add adds an element to the set. Returns true if newly added.
	Add(element string) bool

	// Has checks if an element exists in the set.
	Has(element string) bool

	// Count returns the exact cardinality.
	Count() int

	// Members returns all elements (use with care on large sets).
	Members() []string

	// Intersect returns the count of elements also in the other set.
	Intersect(other Set) int

	// Reset clears the set.
	Reset() error
}

type Timer interface {
	// Record adds a latency sample (in nanoseconds).
	Record(duration int64)

	// RecordMs adds a latency sample in milliseconds.
	RecordMs(ms float64)

	// Count returns the number of samples.
	Count() int64

	// Mean returns the average latency in nanoseconds.
	Mean() float64

	// Percentile returns the p-th percentile (0-100) in nanoseconds.
	// e.g. Percentile(95) for P95.
	Percentile(p float64) float64

	// Reset clears all samples.
	Reset() error
}

type TimerSummary struct {
	Count int64   `json:"count"`
	Mean  float64 `json:"mean"`
	P50   float64 `json:"p50"`
	P95   float64 `json:"p95"`
	P99   float64 `json:"p99"`
}

type WebsiteMetrics struct {
	// contains filtered or unexported fields
}