package service

import (
	"context"
	"strings"
	"time"

	"git.apinb.com/bsm-sdk/core/print"
	"git.apinb.com/bsm-sdk/core/vars"
	clientv3 "go.etcd.io/etcd/client/v3"
)

// ServiceRegister 创建租约注册服务
type ServiceRegister struct {
	cli     *clientv3.Client //etcd client
	leaseID clientv3.LeaseID //租约ID
	//租约keepalieve相应chan
	keepAliveChan <-chan *clientv3.LeaseKeepAliveResponse
	key           string //key
	val           string //value
}

// NewRegister 注册服务至路由表.
//
// ec:EtcdConfig;
//
// routeKey: ServiceRouteRootPrefix + ServiceKey + "/" + utils.GetLocationIP() + addr;
//
// gs:grpc.Server;
func RegisterService(cli *clientv3.Client, routeKey string, methods []string, lease int64) (*ServiceRegister, error) {

	ser := &ServiceRegister{
		cli: cli,
		key: routeKey,
		val: strings.Join(methods, ","),
	}

	//申请租约设置时间keepalive
	if err := ser.putKeyWithLease(lease); err != nil {
		return nil, err
	}

	return ser, nil
}

// 设置租约
func (s *ServiceRegister) putKeyWithLease(lease int64) error {
	//设置租约时间
	resp, err := s.cli.Grant(context.Background(), lease)
	if err != nil {
		return err
	}
	//注册服务并绑定租约
	_, err = s.cli.Put(context.Background(), s.key, s.val, clientv3.WithLease(resp.ID))
	if err != nil {
		return err
	}
	//设置续租 定期发送需求请求
	leaseRespChan, err := s.cli.KeepAlive(context.Background(), resp.ID)

	if err != nil {
		return err
	}
	s.leaseID = resp.ID
	s.keepAliveChan = leaseRespChan
	return nil
}

// ListenLeaseRespChan 监听 续租情况
func (s *ServiceRegister) ListenLeaseRespChan() {
	for {
		select {
		case leaseKeepResp := <-s.keepAliveChan:
			if leaseKeepResp == nil {
				//log.Println("close lease.")
				return
			} else {
				goto END
			}
		}
	END:
		time.Sleep(500 * time.Millisecond)
	}
}

// Close 注销服务
func (s *ServiceRegister) Close() error {
	//撤销租约
	if _, err := s.cli.Revoke(context.Background(), s.leaseID); err != nil {
		return err
	}
	return s.cli.Close()
}

func (s *ServiceRegister) SetAnonymous(key string, urls []string) {
	// remove reppeat, clear service all anonymous uri.
	anonymous, _ := s.cli.Get(context.Background(), key)

	var as []string
	if len(anonymous.Kvs) > 0 {
		val := string(anonymous.Kvs[0].Value)
		as = strings.Split(val, ",")
	}

	as = append(clearService(as), urls...)
	newAnonymous := strings.Join(as, ",")

	// put anonymous to etcd
	_, err := s.cli.Put(context.Background(), key, newAnonymous)

	if err != nil {
		print.Error("[BSM Register] Anonymous Fail.")
	} else {
		print.Info("[BSM Register] Anonymous: %s", newAnonymous)
	}

}

func clearService(as []string) (out []string) {
	for _, v := range as {
		if len(v) >= len(vars.ServiceKey) {
			if v[0:len(vars.ServiceKey)] != vars.ServiceKey {
				out = append(out, v)
			}
		}
	}
	return
}