telemetry

type Bucket struct {
	UpperBound float64
	Count      uint64
}

type Collector = prometheus.Collector

type Component interface {
	// Handler returns an http handler to expose the internal metrics
	Handler() http.Handler
	// Reset resets all tracked telemetry
	Reset()
	// RegisterCollector Registers a Collector with the prometheus registry
	RegisterCollector(c Collector)
	// UnregisterCollector unregisters a Collector with the prometheus registry
	UnregisterCollector(c Collector) bool
	// NewCounter creates a Counter with default options for telemetry purpose.
	NewCounter(subsystem, name string, tags []string, help string) Counter
	// NewCounterWithOpts creates a Counter with the given options for telemetry purpose.
	NewCounterWithOpts(subsystem, name string, tags []string, help string, opts Options) Counter

	// NewSimpleCounter creates a new SimpleCounter with default options.
	NewSimpleCounter(subsystem, name, help string) SimpleCounter
	// NewSimpleCounterWithOpts creates a new SimpleCounter.
	NewSimpleCounterWithOpts(subsystem, name, help string, opts Options) SimpleCounter

	// NewGauge creates a Gauge with default options for telemetry purpose.
	NewGauge(subsystem, name string, tags []string, help string) Gauge
	// NewGaugeWithOpts creates a Gauge with the given options for telemetry purpose.
	NewGaugeWithOpts(subsystem, name string, tags []string, help string, opts Options) Gauge

	// NewSimpleGauge creates a new SimpleGauge with default options.
	NewSimpleGauge(subsystem, name, help string) SimpleGauge
	// NewSimpleGaugeWithOpts creates a new SimpleGauge.
	NewSimpleGaugeWithOpts(subsystem, name, help string, opts Options) SimpleGauge

	// NewHistogram creates a Histogram with default options for telemetry purpose.
	NewHistogram(subsystem, name string, tags []string, help string, buckets []float64) Histogram
	// NewHistogramWithOpts creates a Histogram with the given options for telemetry purpose.
	NewHistogramWithOpts(subsystem, name string, tags []string, help string, buckets []float64, opts Options) Histogram

	// NewSimpleHistogram creates a new SimpleHistogram with default options.
	NewSimpleHistogram(subsystem, name, help string, buckets []float64) SimpleHistogram
	// NewSimpleHistogramWithOpts creates a new SimpleHistogram.
	NewSimpleHistogramWithOpts(subsystem, name, help string, buckets []float64, opts Options) SimpleHistogram

	// Gather exposes metrics from the general or default telemetry registry (see options.DefaultMetric)
	Gather(defaultGather bool) ([]*MetricFamily, error)

	// GatherText exposes metrics from the general or default telemetry registry (see options.DefaultMetric) in text format
	GatherText(defaultGather bool, filter MetricFilter) (string, error)
}

type Counter interface {
	// InitializeToZero creates the counter with the given tags and initializes it to 0.
	// This method is intended to be used when the counter value is important to
	// send even before any incrementing/addition is done on it.
	InitializeToZero(tagsValue ...string)
	// Inc increments the counter with the given tags value.
	Inc(tagsValue ...string)
	// Add adds the given value to the counter with the given tags value.
	Add(value float64, tagsValue ...string)
	// Delete deletes the value for the counter with the given tags value.
	Delete(tagsValue ...string)
	// IncWithTags increments the counter with the given tags.
	// Even if less convenient, this signature could be used in hot path
	// instead of Inc(...string) to avoid escaping the parameters on the heap.
	IncWithTags(tags map[string]string)
	// AddWithTags adds the given value to the counter with the given tags.
	// Even if less convenient, this signature could be used in hot path
	// instead of Add(float64, ...string) to avoid escaping the parameters on the heap.
	AddWithTags(value float64, tags map[string]string)
	// DeleteWithTags deletes the value for the counter with the given tags.
	// Even if less convenient, this signature could be used in hot path
	// instead of Delete(...string) to avoid escaping the parameters on the heap.
	DeleteWithTags(tags map[string]string)
	// WithValues returns SimpleCounter for this metric with the given tag values.
	WithValues(tagsValue ...string) SimpleCounter
	// WithTags returns SimpleCounter for this metric with the given tag values.
	WithTags(tags map[string]string) SimpleCounter
}

type Gauge interface {
	// Set stores the value for the given tags.
	Set(value float64, tagsValue ...string)
	// Inc increments the Gauge value.
	Inc(tagsValue ...string)
	// Dec decrements the Gauge value.
	Dec(tagsValue ...string)
	// Add adds the value to the Gauge value.
	Add(value float64, tagsValue ...string)
	// Sub subtracts the value to the Gauge value.
	Sub(value float64, tagsValue ...string)
	// Delete deletes the value for the Gauge with the given tags.
	Delete(tagsValue ...string)
	// DeletePartialMatch deletes the values for the Gauges that match the subset of given tags
	DeletePartialMatch(tags map[string]string)
	// WithValues returns SimpleGauge for this metric with the given tag values.
	WithValues(tagsValue ...string) SimpleGauge
	// WithTags returns SimpleGauge for this metric with the given tag values.
	WithTags(tags map[string]string) SimpleGauge
}

type Histogram interface {
	// Observe the value to the Histogram value.
	Observe(value float64, tagsValue ...string)
	// Delete deletes the value for the Histogram with the given tags.
	Delete(tagsValue ...string)
	// WithValues returns SimpleHistogram for this metric with the given tag values.
	WithValues(tagsValue ...string) SimpleHistogram
	// WithTags returns SimpleHistogram for this metric with the given tag values.
	WithTags(tags map[string]string) SimpleHistogram
}

type HistogramValue struct {
	Count   uint64
	Sum     float64
	Buckets []Bucket
}

type MetricFamily = dto.MetricFamily

type MetricFilter func(*MetricFamily) bool

type Options struct {
	// NoDoubleUnderscoreSep is set to true when you don't want to
	// separate the subsystem and the name with a double underscore separator.
	//
	// This option is not compatible with the cross-org agent telemetry
	NoDoubleUnderscoreSep bool

	// DefaultMetric exports metric by default via built-in agent_telemetry core check.
	DefaultMetric bool
}

type SimpleCounter interface {
	// Inc increments the counter.
	Inc()
	// Add increments the counter by given amount.
	Add(float64)
	// Get gets the current counter value
	Get() float64
}

type SimpleGauge interface {
	// Inc increments the gaguge.
	Inc()
	// Dec decrements the gauge.
	Dec()
	// Add increments the gauge by given amount.
	Add(float64)
	// Sub decrements the gauge by given amount.
	Sub(float64)
	// Set sets the value of the gauge.
	Set(float64)
	// Get gets the value of the gauge.
	Get() float64
}

type SimpleHistogram interface {
	// Observe the value to the Histogram value.
	Observe(value float64)

	// Get gets the current histogram values
	Get() HistogramValue
}