package metrics

import (
	"time"

	"github.com/prometheus/client_golang/prometheus"
	ctrl "sigs.k8s.io/controller-runtime"

	"edge-infra.dev/pkg/k8s/runtime/conditions"
	"edge-infra.dev/pkg/k8s/runtime/controller/metrics"
	k8smetrics "edge-infra.dev/pkg/k8s/runtime/controller/metrics"
	"edge-infra.dev/pkg/sds/display/constants"
	v2 "edge-infra.dev/pkg/sds/display/k8s/apis/v2"
)

const (
	nodeLabel    = "node"
	enabledLabel = "enabled"
	configLabel  = "config"
	defaultLabel = "default"
	statusLabel  = "status"
)

var NodeDisplayConfigReadinessMetric prometheus.GaugeVec = *prometheus.NewGaugeVec(
	prometheus.GaugeOpts{
		Name: metrics.Name(constants.DisplayctlName, "nodedisplayconfig_readiness"),
		Help: "Metric to show the NodeDisplayConfig readiness.",
	},
	[]string{nodeLabel, enabledLabel, configLabel, defaultLabel, statusLabel},
)

var NodeDisplayConfigDurationMetric prometheus.HistogramVec = *prometheus.NewHistogramVec(
	prometheus.HistogramOpts{
		Name:    metrics.Name(constants.DisplayctlName, "nodedisplayconfig_reconcile_duration_seconds"),
		Help:    "Metric to show the NodeDisplayConfig reconcile duration in seconds.",
		Buckets: prometheus.LinearBuckets(0.0, 0.2, 10),
	},
	[]string{nodeLabel},
)

type Metrics struct {
	Metrics        k8smetrics.Metrics
	reconcileStart time.Time
}

func New(mgr ctrl.Manager, name string) *Metrics {
	return &Metrics{
		Metrics: k8smetrics.New(
			mgr,
			name,
			k8smetrics.WithCollectors(
				NodeDisplayConfigReadinessMetric,
				NodeDisplayConfigDurationMetric,
			),
		),
	}
}

func (m *Metrics) Reconciling() {
	m.reconcileStart = time.Now()
	NodeDisplayConfigReadinessMetric.Reset()
}

func (m *Metrics) RecordReconcile(nodeDisplayConfig *v2.NodeDisplayConfig) {
	if !nodeDisplayConfig.DeletionTimestamp.IsZero() {
		return
	}

	m.recordReadiness(nodeDisplayConfig)
	m.recordReconcileDuration(nodeDisplayConfig)
}

func (m *Metrics) recordReadiness(nodeDisplayConfig *v2.NodeDisplayConfig) {
	labels := map[string]string{
		nodeLabel:    nodeDisplayConfig.GetName(),
		statusLabel:  "",
		defaultLabel: "True",
		enabledLabel: "True",
		configLabel:  "False",
	}

	if condition := conditions.Get(nodeDisplayConfig, v2.DisplayManagerConfiguredCondition); condition != nil {
		labels[statusLabel] = condition.Reason
	}
	if condition := conditions.Get(nodeDisplayConfig, v2.DefaultCondition); condition != nil {
		labels[statusLabel] = string(condition.Status)
	}
	if condition := conditions.Get(nodeDisplayConfig, v2.DisplayctlEnabledCondition); condition != nil {
		labels[statusLabel] = string(condition.Status)
	}
	if condition := conditions.Get(nodeDisplayConfig, v2.DisplayManagerConfigCondition); condition != nil {
		labels[statusLabel] = string(condition.Status)
	}

	if conditions.IsReady(nodeDisplayConfig) {
		NodeDisplayConfigReadinessMetric.With(labels).Set(1)
	} else {
		NodeDisplayConfigReadinessMetric.With(labels).Set(0)
	}
}

func (m *Metrics) recordReconcileDuration(nodeDisplayConfig *v2.NodeDisplayConfig) {
	labels := map[string]string{
		nodeLabel: nodeDisplayConfig.GetName(),
	}

	seconds := time.Since(m.reconcileStart).Seconds()
	NodeDisplayConfigDurationMetric.With(labels).Observe(seconds)
}