package pool

import (
	"context"
	"time"
)

type healthCheck struct {
	cancel   context.CancelFunc
	closedCh chan struct{}

	clientRebalanceInterval time.Duration
}

func newHealthCheck(clientRebalanceInterval time.Duration) *healthCheck {
	var h healthCheck
	h.clientRebalanceInterval = clientRebalanceInterval
	h.closedCh = make(chan struct{})
	return &h
}

// startRebalance runs loop to monitor connection healthy status.
func (h *healthCheck) startRebalance(ctx context.Context, callback func(ctx context.Context)) {
	ctx, cancel := context.WithCancel(ctx)
	h.cancel = cancel

	go func() {
		ticker := time.NewTicker(h.clientRebalanceInterval)
		defer ticker.Stop()

		for {
			select {
			case <-ctx.Done():
				close(h.closedCh)
				return
			case <-ticker.C:
				callback(ctx)
				ticker.Reset(h.clientRebalanceInterval)
			}
		}
	}()
}

func (h *healthCheck) stopRebalance() {
	h.cancel()
	<-h.closedCh
}