module metrics

import io

[params]
pub struct Metric {
pub:
	name   string      [required]
	labels [][2]string
}

pub fn (m &Metric) str() string {
	return '${m.name} ${m.labels}'
}

pub interface MetricsCollector {
	counter_get(metric Metric) ?u64
	counters() []Metric
	histogram_get(metric Metric) ?Histogram
	histograms() []Metric
	gauge_get(metric Metric) ?f64
	gauges() []Metric
mut:
	counter_set(val u64, metric Metric)
	counter_increment(metric Metric)
	histogram_buckets_set(name string, buckets []f64)
	histogram_record(value f64, metric Metric)
	gauge_set(value f64, metric Metric)
	gauge_add(value f64, metric Metric)
	gauge_sub(value f64, metric Metric)
}

pub interface MetricsExporter {
	load(prefix string, collector MetricsCollector)
	export_to_writer(writer io.Writer) !
	export_to_string() !string
	serialize_metric(metric Metric) string
}