package metrics

import (
	"github.com/prometheus/client_golang/prometheus"
	"rgdd.se/silentct/internal/monitor"
	"rgdd.se/silentct/pkg/storage/index"
)

type Metrics struct {
	logSize          *prometheus.GaugeVec
	logIndex         *prometheus.GaugeVec
	logTimestamp     *prometheus.GaugeVec
	certificateAlert *prometheus.GaugeVec
	errorCounter     prometheus.Counter
}

func NewMetrics(registry *prometheus.Registry) *Metrics {
	m := &Metrics{
		logSize: prometheus.NewGaugeVec(
			prometheus.GaugeOpts{
				Name: "silentct_log_size",
				Help: "The number of entries in the log.",
			},
			[]string{"id"},
		),
		logIndex: prometheus.NewGaugeVec(
			prometheus.GaugeOpts{
				Name: "silentct_log_index",
				Help: "The next log entry to be downloaded.",
			},
			[]string{"id"},
		),
		logTimestamp: prometheus.NewGaugeVec(
			prometheus.GaugeOpts{
				Name: "silentct_log_timestamp",
				Help: "The log's UNIX timestamp in ms.",
			},
			[]string{"id"},
		),
		certificateAlert: prometheus.NewGaugeVec(
			prometheus.GaugeOpts{
				Name: "silentct_certificate_alert",
				Help: "The time the certificate without allowlisting was found.",
			},
			[]string{"stored_at"},
		),
		errorCounter: prometheus.NewCounter(
			prometheus.CounterOpts{
				Name: "silentct_error_counter",
				Help: "The number of errors propagated to the main loop.",
			},
		),
	}

	registry.MustRegister(m.logSize, m.logIndex, m.logTimestamp, m.certificateAlert, m.errorCounter)
	return m
}

func (m *Metrics) LogState(state monitor.State) {
	id := state.LogID.Base64String()
	m.logIndex.WithLabelValues(id).Set(float64(state.NextIndex))
	m.logSize.WithLabelValues(id).Set(float64(state.TreeSize))
	m.logTimestamp.WithLabelValues(id).Set(float64(state.Timestamp))
}

func (m *Metrics) RemoveLogState(state monitor.State) {
	id := state.LogID.Base64String()
	m.logIndex.Delete(prometheus.Labels{"id": id})
	m.logSize.Delete(prometheus.Labels{"id": id})
	m.logTimestamp.Delete(prometheus.Labels{"id": id})
}

func (m *Metrics) CertificateAlert(alerts []index.CertificateInfo) {
	m.certificateAlert.Reset()
	for _, alert := range alerts {
		m.certificateAlert.WithLabelValues(alert.StoredAt).Set(float64(alert.ObservedAt.Unix()))
	}
}

func (m *Metrics) CountError() {
	m.errorCounter.Inc()
}