package parser

import (
	"context"
	"fmt"
	"log"
	"time"

	uuid "github.com/satori/go.uuid"
	clientv3 "go.etcd.io/etcd/client/v3"
	"go.etcd.io/etcd/client/v3/naming/endpoints"
)

var cli *clientv3.Client

func GetEtcdClient() *clientv3.Client {
	return cli
}

func EctdRegister(etcdAddrs []string, serviceName,serviceAddr,prefix string) {
	var (
		err error
	)

	cli, err = clientv3.New(clientv3.Config{
		Endpoints:   etcdAddrs,
		DialTimeout: 5 * time.Second,
	})
	if err != nil {
		panic(err)
	}

	// 注册续租
	err = relet(serviceName,
		serviceAddr,
		prefix,
	)
	if err != nil {
		panic(err)
	}
}

func getValue(addr string) string {
	return `{"Addr:":"http://` + addr + `"}`
}

// 续租
func relet(serviceName, serviceAddr, prefix string) error {
	var ctx = context.Background()
	// 创建一个租约
	lease := clientv3.NewLease(cli)
	cancelCtx, cancel := context.WithTimeout(ctx, time.Second*3)
	defer cancel()

	leaseResp, err := lease.Grant(cancelCtx, 3)
	if err != nil {
		return err
	}

	// 长链接
	leaseChannel, err := lease.KeepAlive(ctx, leaseResp.ID)
	if err != nil {
		return err
	}

	em, err := endpoints.NewManager(cli, prefix)
	if err != nil {
		return err
	}

	cancelCtx, cancel = context.WithTimeout(ctx, time.Second*3)
	defer cancel()
	uuid, _ := uuid.NewV4()
	if err := em.AddEndpoint(cancelCtx, fmt.Sprintf("%s/%s/%s", prefix, serviceName, uuid.String()), endpoints.Endpoint{
		Addr: serviceAddr,
	}, clientv3.WithLease(leaseResp.ID)); err != nil {
		return err
	}

	log.Println("Register etcd success")

	del := func() {
		log.Println("Register close")

		cancelCtx, cancel = context.WithTimeout(ctx, time.Second*3)
		defer cancel()
		em.DeleteEndpoint(cancelCtx, serviceName)

		lease.Close()
	}

	// 保持注册状态(连接断开重连)
	keepRegister(ctx, leaseChannel, del, serviceName, serviceAddr, prefix)

	return nil
}

func keepRegister(ctx context.Context, leaseChannel <-chan *clientv3.LeaseKeepAliveResponse, cleanFunc func(), serviceName, serviceAddr, prefix string) {
	go func() {
		failedCount := 0
		for {
			select {
			case resp := <-leaseChannel:
				if resp != nil {
					//log.Println("keep alive success.")
				} else {
					log.Println("keep alive failed.")
					failedCount++
					for failedCount > 3 {
						cleanFunc()
						if err := relet(serviceName, serviceAddr, prefix); err != nil {
							time.Sleep(time.Second)
							continue
						}
						return
					}
					continue
				}
			case <-ctx.Done():
				cleanFunc()
				cli.Close()
				return
			}
		}
	}()
}

func UnRegisterEtcd(serviceName, serviceAddr string) {
}