package aggregate

import (
	"math"

	"github.com/pingcap-inc/clinic/pkg/ngm/statements/api"
	"github.com/pingcap-inc/clinic/pkg/ngm/statements/load"
)

func AggMaxLocalLatchWaitTime() Aggregator {
	return &MaxLocalLatchWaitTime{math.MinInt64}
}

type MaxLocalLatchWaitTime struct {
	max int64
}

var _ Aggregator = (*MaxLocalLatchWaitTime)(nil)

func (a *MaxLocalLatchWaitTime) Add(record *load.StmtRecord) {
	if record.MaxLocalLatchTime.Nanoseconds() > a.max {
		a.max = record.MaxLocalLatchTime.Nanoseconds()
	}
}

func (a *MaxLocalLatchWaitTime) Merge(agg Aggregator) {
	if agg, ok := agg.(*MaxLocalLatchWaitTime); ok {
		if agg.max > a.max {
			a.max = agg.max
		}
	}
}

func (a *MaxLocalLatchWaitTime) Output(model *api.Model) {
	model.MaxLocalLatchWaitTime = int(a.max)
}