package etcdv3

import (
	"context"
	"crypto/tls"
	"strings"
	"time"

	"github.com/golang/glog"

	"github.com/coreos/etcd/clientv3"
)

// Register register service with name as prefix to etcd, multi etcd addr should use ; to split
func Register(etcdAddr string, name string, addr string, ttl int64, tls *tls.Config) error {
	var err error

	if cli == nil {
		cli, err = clientv3.New(clientv3.Config{
			Endpoints:   strings.Split(etcdAddr, ","),
			DialTimeout: 15 * time.Second,
			TLS:         tls,
		})
		if err != nil {
			return err
		}
	}

	ticker := time.NewTicker(time.Second * time.Duration(ttl))

	go func() {
		for {
			getResp, err := cli.Get(context.Background(), "/"+schema+"/"+name+"/"+addr)
			if err != nil {
				glog.Errorln(err)
			} else if getResp.Count == 0 {
				err = withAlive(name, addr, ttl)
				if err != nil {
					glog.Errorln(err)
				}
			} else {
				// do nothing
			}

			<-ticker.C
		}
	}()

	return nil
}

func withAlive(name string, addr string, ttl int64) error {
	leaseResp, err := cli.Grant(context.Background(), ttl)
	if err != nil {
		return err
	}

	_, err = cli.Put(context.Background(), "/"+schema+"/"+name+"/"+addr, addr, clientv3.WithLease(leaseResp.ID))
	if err != nil {
		return err
	}

	_, err = cli.KeepAlive(context.Background(), leaseResp.ID)
	if err != nil {
		return err
	}
	return nil
}

// UnRegister remove service from etcd
func UnRegister(name string, addr string) error {
	if cli != nil {
		_, err := cli.Delete(context.Background(), "/"+schema+"/"+name+"/"+addr)
		if err != nil {
			return err
		}
	}
	return nil
}