package metrics

import (
	"strconv"
	"time"

	"git.frostfs.info/TrueCloudLab/frostfs-observability/metrics"
	"github.com/prometheus/client_golang/prometheus"
)

type BadgerStoreMetrics interface {
	SetMode(shardID, path string, readOnly bool)
	Close(shardID, path string)
	MethodDuration(shardID, path string, method string, d time.Duration, success bool)
	AddPut(shardID, path string, size int)
	AddGet(shardID, path string, size int)
}

var _ BadgerStoreMetrics = (*badgerStoreMetrics)(nil)

type badgerStoreMetrics struct {
	mode        *shardIDPathModeValue
	reqDuration *prometheus.HistogramVec
	put         *prometheus.CounterVec
	get         *prometheus.CounterVec
}

func newbadgerStoreMetrics() *badgerStoreMetrics {
	return &badgerStoreMetrics{
		mode: newShardIDPathMode(badgerStoreSubSystem, "mode", "BadgerStore mode"),
		reqDuration: metrics.NewHistogramVec(prometheus.HistogramOpts{
			Namespace: namespace,
			Subsystem: badgerStoreSubSystem,
			Name:      "request_duration_seconds",
			Help:      "Accumulated BadgerStore request process duration",
		}, []string{shardIDLabel, pathLabel, successLabel, methodLabel}),
		put: metrics.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: badgerStoreSubSystem,
			Name:      "put_bytes",
			Help:      "Accumulated payload size written to BadgerStore",
		}, []string{shardIDLabel, pathLabel}),
		get: metrics.NewCounterVec(prometheus.CounterOpts{
			Namespace: namespace,
			Subsystem: badgerStoreSubSystem,
			Name:      "get_bytes",
			Help:      "Accumulated payload size read from BadgerStore",
		}, []string{shardIDLabel, pathLabel}),
	}
}

// AddGet implements BadgerStoreMetrics.
func (b *badgerStoreMetrics) AddGet(shardID string, path string, size int) {
	b.get.With(prometheus.Labels{
		shardIDLabel: shardID,
		pathLabel:    path,
	}).Add(float64(size))
}

// AddPut implements BadgerStoreMetrics.
func (b *badgerStoreMetrics) AddPut(shardID string, path string, size int) {
	b.put.With(prometheus.Labels{
		shardIDLabel: shardID,
		pathLabel:    path,
	}).Add(float64(size))
}

// Close implements BadgerStoreMetrics.
func (b *badgerStoreMetrics) Close(shardID string, path string) {
	b.mode.SetMode(shardID, path, closedMode)
	b.reqDuration.DeletePartialMatch(prometheus.Labels{
		shardIDLabel: shardID,
		pathLabel:    path,
	})
	b.get.DeletePartialMatch(prometheus.Labels{
		shardIDLabel: shardID,
		pathLabel:    path,
	})
	b.put.DeletePartialMatch(prometheus.Labels{
		shardIDLabel: shardID,
		pathLabel:    path,
	})
}

// MethodDuration implements BadgerStoreMetrics.
func (b *badgerStoreMetrics) MethodDuration(shardID string, path string, method string, d time.Duration, success bool) {
	b.reqDuration.With(prometheus.Labels{
		shardIDLabel: shardID,
		pathLabel:    path,
		successLabel: strconv.FormatBool(success),
		methodLabel:  method,
	}).Observe(d.Seconds())
}

// SetMode implements BadgerStoreMetrics.
func (b *badgerStoreMetrics) SetMode(shardID string, path string, readOnly bool) {
	b.mode.SetMode(shardID, path, modeFromBool(readOnly))
}