package authserver

import (
	"fmt"
	"time"

	"github.com/gin-gonic/gin"
	"github.com/penglongli/gin-metrics/ginmetrics"
)

const (
	metricPath        = "/metrics"
	maxLatencySeconds = 1
	authRequests      = "auth_request_total"
	authOperations    = "auth_query_total"
	authSlowReQuests  = "auth_slow_request_total"
	authResponseTime  = "auth_query_duration"
)

func useMetrics(r gin.IRoutes) {
	// get global Monitor object
	m := ginmetrics.GetMonitor()
	m.SetMetricPath(metricPath)
	m.SetSlowTime(maxLatencySeconds)

	_ = m.AddMetric(&ginmetrics.Metric{
		Type:        ginmetrics.Counter,
		Name:        authRequests,
		Description: "count all auth requests.",
		Labels:      nil,
	})

	_ = m.AddMetric(&ginmetrics.Metric{
		Type:        ginmetrics.Counter,
		Name:        authOperations,
		Description: "count all auth requests by status.",
		Labels:      []string{"status"},
	})

	_ = m.AddMetric(&ginmetrics.Metric{
		Type:        ginmetrics.Counter,
		Name:        authSlowReQuests,
		Description: fmt.Sprintf("count all auth slow requests by status. max_lentency=%d sec.", maxLatencySeconds),
		Labels:      []string{"status"},
	})

	m.SetDuration([]float64{0.1, 0.3, 1.2, 5, 10})
	_ = m.AddMetric(&ginmetrics.Metric{
		Type:        ginmetrics.Histogram,
		Name:        authResponseTime,
		Description: "the time auth server took handle the request by status.",
		Labels:      []string{"status"},
		Buckets:     []float64{0.1, 0.3, 1.2, 5, 10},
	})

	m.Use(r)
}

func handleMetrics(success bool, start time.Time) {
	latency := time.Since(start)

	_ = ginmetrics.GetMonitor().GetMetric(authRequests).Inc(nil)

	status := "verified"
	if !success {
		status = "denied"
	}

	labels := []string{status}

	// metrics per name and status
	_ = ginmetrics.GetMonitor().GetMetric(authOperations).Inc(labels)

	// slow metrics per name, operation and status
	if int32(latency.Seconds()) > maxLatencySeconds {
		_ = ginmetrics.GetMonitor().GetMetric(authSlowReQuests).Inc(labels)
	}

	// metrics for response time
	_ = ginmetrics.GetMonitor().GetMetric(authResponseTime).Observe([]string{status}, latency.Seconds())
}