func TestKVCompactError(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 1})
	defer clus.Terminate(t)

	kv := clientv3.NewKV(clus.RandClient())
	ctx := context.TODO()

	for i := 0; i < 5; i++ {
		if _, err := kv.Put(ctx, "foo", "bar"); err != nil {
			t.Fatalf("couldn't put 'foo' (%v)", err)
		}
	}
	_, err := kv.Compact(ctx, 6)
	if err != nil {
		t.Fatalf("couldn't compact 6 (%v)", err)
	}

	_, err = kv.Compact(ctx, 6)
	if err != rpctypes.ErrCompacted {
		t.Fatalf("expected %v, got %v", rpctypes.ErrCompacted, err)
	}

	_, err = kv.Compact(ctx, 100)
	if err != rpctypes.ErrFutureRev {
		t.Fatalf("expected %v, got %v", rpctypes.ErrFutureRev, err)
	}
}

func TestKVPutError(t *testing.T) {
	defer testutil.AfterTest(t)

	var (
		maxReqBytes = 1.5 * 1024 * 1024
		quota       = int64(maxReqBytes * 1.2)
	)
	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 1, QuotaBackendBytes: quota})
	defer clus.Terminate(t)

	kv := clientv3.NewKV(clus.RandClient())
	ctx := context.TODO()

	_, err := kv.Put(ctx, "", "bar")
	if err != rpctypes.ErrEmptyKey {
		t.Fatalf("expected %v, got %v", rpctypes.ErrEmptyKey, err)
	}

	_, err = kv.Put(ctx, "key", strings.Repeat("a", int(maxReqBytes+100))) // 1.5MB
	if err != rpctypes.ErrRequestTooLarge {
		t.Fatalf("expected %v, got %v", rpctypes.ErrRequestTooLarge, err)
	}

	_, err = kv.Put(ctx, "foo1", strings.Repeat("a", int(maxReqBytes-50)))
	if err != nil { // below quota
		t.Fatal(err)
	}

	time.Sleep(500 * time.Millisecond) // give enough time for commit

	_, err = kv.Put(ctx, "foo2", strings.Repeat("a", int(maxReqBytes-50)))
	if err != rpctypes.ErrNoSpace { // over quota
		t.Fatalf("expected %v, got %v", rpctypes.ErrNoSpace, err)
	}
}

func ExampleLease_keepAlive() {
	cli, err := clientv3.New(clientv3.Config{
		Endpoints:   endpoints,
		DialTimeout: dialTimeout,
	})
	if err != nil {
		log.Fatal(err)
	}
	defer cli.Close()

	kvc := clientv3.NewKV(cli)
	lapi := clientv3.NewLease(cli)
	defer lapi.Close()

	resp, err := lapi.Create(context.TODO(), 5)
	if err != nil {
		log.Fatal(err)
	}

	_, err = kvc.Put(context.TODO(), "foo", "bar", clientv3.WithLease(lease.LeaseID(resp.ID)))
	if err != nil {
		log.Fatal(err)
	}

	// the key 'foo' will be kept forever
	_, err = lapi.KeepAlive(context.TODO(), lease.LeaseID(resp.ID))
	if err != nil {
		log.Fatal(err)
	}
}

func TestLeaseRevoke(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
	defer clus.Terminate(t)

	lapi := clientv3.NewLease(clus.RandClient())
	defer lapi.Close()

	kv := clientv3.NewKV(clus.RandClient())

	resp, err := lapi.Create(context.Background(), 10)
	if err != nil {
		t.Errorf("failed to create lease %v", err)
	}

	_, err = lapi.Revoke(context.Background(), lease.LeaseID(resp.ID))
	if err != nil {
		t.Errorf("failed to revoke lease %v", err)
	}

	_, err = kv.Put(context.TODO(), "foo", "bar", clientv3.WithLease(lease.LeaseID(resp.ID)))
	if err != v3rpc.ErrLeaseNotFound {
		t.Fatalf("err = %v, want %v", err, v3rpc.ErrLeaseNotFound)
	}
}

func ExampleLease_create() {
	cli, err := clientv3.New(clientv3.Config{
		Endpoints:   endpoints,
		DialTimeout: dialTimeout,
	})
	if err != nil {
		log.Fatal(err)
	}
	defer cli.Close()

	kvc := clientv3.NewKV(cli)
	lapi := clientv3.NewLease(cli)
	defer lapi.Close()

	// minimum lease TTL is 5-second
	resp, err := lapi.Create(context.TODO(), 5)
	if err != nil {
		log.Fatal(err)
	}

	// after 5 seconds, the key 'foo' will be removed
	_, err = kvc.Put(context.TODO(), "foo", "bar", clientv3.WithLease(lease.LeaseID(resp.ID)))
	if err != nil {
		log.Fatal(err)
	}
}

func TestKVDelete(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
	defer clus.Terminate(t)

	kv := clientv3.NewKV(clus.RandClient())
	ctx := context.TODO()

	presp, err := kv.Put(ctx, "foo", "")
	if err != nil {
		t.Fatalf("couldn't put 'foo' (%v)", err)
	}
	if presp.Header.Revision != 2 {
		t.Fatalf("presp.Header.Revision got %d, want %d", presp.Header.Revision, 2)
	}
	resp, err := kv.Delete(ctx, "foo")
	if err != nil {
		t.Fatalf("couldn't delete key (%v)", err)
	}
	if resp.Header.Revision != 3 {
		t.Fatalf("resp.Header.Revision got %d, want %d", resp.Header.Revision, 3)
	}
	gresp, err := kv.Get(ctx, "foo")
	if err != nil {
		t.Fatalf("couldn't get key (%v)", err)
	}
	if len(gresp.Kvs) > 0 {
		t.Fatalf("gresp.Kvs got %+v, want none", gresp.Kvs)
	}
}

func TestTxnWriteFail(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
	defer clus.Terminate(t)

	kv := clientv3.NewKV(clus.Client(0))
	clus.Members[0].Stop(t)
	<-clus.Members[0].StopNotify()

	resp, err := kv.Txn().Then(clientv3.OpPut("foo", "bar", 0)).Commit()
	if err == nil {
		t.Fatalf("expected error, got response %v", resp)
	}

	// reconnect so cluster terminate doesn't complain about double-close
	clus.Members[0].Restart(t)

	// and ensure the put didn't take
	gresp, gerr := kv.Get("foo", 0)
	if gerr != nil {
		t.Fatal(gerr)
	}
	if len(gresp.Kvs) != 0 {
		t.Fatalf("expected no keys, got %v", gresp.Kvs)
	}
}

func ExampleKV_compact() {
	cli, err := clientv3.New(clientv3.Config{
		Endpoints:   endpoints,
		DialTimeout: dialTimeout,
	})
	if err != nil {
		log.Fatal(err)
	}
	defer cli.Close()

	kvc := clientv3.NewKV(cli)

	ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
	resp, err := kvc.Get(ctx, "foo")
	cancel()
	if err != nil {
		log.Fatal(err)
	}
	compRev := resp.Header.Revision // specify compact revision of your choice

	ctx, cancel = context.WithTimeout(context.Background(), requestTimeout)
	err = kvc.Compact(ctx, compRev)
	cancel()
	if err != nil {
		log.Fatal(err)
	}
}

func Demo(key string, auth3 *Auth3) {
	cli, err := Get().API(auth3)
	if err != nil {
		log.Fatal(err)
	}

	kvc := clientv3.NewKV(cli)

	log.Println("init key ")
	if err := initKey(key, kvc); err != nil {
		log.Fatal(err)
	}

	for i := 0; i < 1000; i++ {
		value := strconv.Itoa(i)
		log.Println("begin ", value)

		if err := require(key, value, kvc); err != nil {
			log.Fatal(err)
		}

		if err := release(key, value, kvc); err != nil {
			log.Fatal(err)
		}

		log.Printf("end %s\n\n", value)
	}
}

func ExampleKV_get() {
	cli, err := clientv3.New(clientv3.Config{
		Endpoints:   endpoints,
		DialTimeout: dialTimeout,
	})
	if err != nil {
		log.Fatal(err)
	}
	defer cli.Close()

	kvc := clientv3.NewKV(cli)

	_, err = kvc.Put(context.TODO(), "foo", "bar")
	if err != nil {
		log.Fatal(err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
	resp, err := kvc.Get(ctx, "foo")
	cancel()
	if err != nil {
		log.Fatal(err)
	}
	for _, ev := range resp.Kvs {
		fmt.Printf("%s : %s\n", ev.Key, ev.Value)
	}
	// foo : bar
}

// txnCommandFunc executes the "txn" command.
func txnCommandFunc(cmd *cobra.Command, args []string) {
	if len(args) != 0 {
		ExitWithError(ExitBadArgs, fmt.Errorf("txn command does not accept argument."))
	}

	if !txnInteractive {
		ExitWithError(ExitBadFeature, fmt.Errorf("txn command only supports interactive mode"))
	}

	reader := bufio.NewReader(os.Stdin)

	txn := clientv3.NewKV(mustClientFromCmd(cmd)).Txn(context.Background())
	fmt.Println("compares:")
	txn.If(readCompares(reader)...)
	fmt.Println("success requests (get, put, delete):")
	txn.Then(readOps(reader)...)
	fmt.Println("failure requests (get, put, delete):")
	txn.Else(readOps(reader)...)

	resp, err := txn.Commit()
	if err != nil {
		ExitWithError(ExitError, err)
	}

	display.Txn(*resp)
}

func TestKVPutWithRequireLeader(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
	defer clus.Terminate(t)

	clus.Members[1].Stop(t)
	clus.Members[2].Stop(t)

	// wait for election timeout, then member[0] will not have a leader.
	var (
		electionTicks = 10
		tickDuration  = 10 * time.Millisecond
	)
	time.Sleep(time.Duration(3*electionTicks) * tickDuration)

	kv := clientv3.NewKV(clus.Client(0))
	_, err := kv.Put(clientv3.WithRequireLeader(context.Background()), "foo", "bar")
	if err != rpctypes.ErrNoLeader {
		t.Fatal(err)
	}

	// clients may give timeout errors since the members are stopped; take
	// the clients so that terminating the cluster won't complain
	clus.Client(1).Close()
	clus.Client(2).Close()
	clus.TakeClient(1)
	clus.TakeClient(2)
}

func ExampleKV_getSortedPrefix() {
	cli, err := clientv3.New(clientv3.Config{
		Endpoints:   endpoints,
		DialTimeout: dialTimeout,
	})
	if err != nil {
		log.Fatal(err)
	}
	defer cli.Close()

	kvc := clientv3.NewKV(cli)

	for i := range make([]int, 3) {
		ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
		_, err = kvc.Put(ctx, fmt.Sprintf("key_%d", i), "value")
		cancel()
		if err != nil {
			log.Fatal(err)
		}
	}

	ctx, cancel := context.WithTimeout(context.Background(), requestTimeout)
	resp, err := kvc.Get(ctx, "key", clientv3.WithPrefix(), clientv3.WithSort(clientv3.SortByKey, clientv3.SortDescend))
	cancel()
	if err != nil {
		log.Fatal(err)
	}
	for _, ev := range resp.Kvs {
		fmt.Printf("%s : %s\n", ev.Key, ev.Value)
	}
	// key_2 : value
	// key_1 : value
	// key_0 : value
}

func TestKVNewAfterClose(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 1})
	defer clus.Terminate(t)

	cli := clus.Client(0)
	clus.TakeClient(0)
	if err := cli.Close(); err != nil {
		t.Fatal(err)
	}

	donec := make(chan struct{})
	go func() {
		kv := clientv3.NewKV(cli)
		if _, err := kv.Get(context.TODO(), "foo"); err != grpc.ErrClientConnClosing {
			t.Fatalf("expected %v, got %v", grpc.ErrClientConnClosing, err)
		}
		close(donec)
	}()
	select {
	case <-time.After(3 * time.Second):
		t.Fatal("kv.Get took too long")
	case <-donec:
	}
}

func TestTxnReadRetry(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
	defer clus.Terminate(t)

	kv := clientv3.NewKV(clus.Client(0))
	clus.Members[0].Stop(t)
	<-clus.Members[0].StopNotify()

	donec := make(chan struct{})
	go func() {
		ctx := context.TODO()
		_, err := kv.Txn(ctx).Then(clientv3.OpGet("foo")).Commit()
		if err != nil {
			t.Fatalf("expected response, got error %v", err)
		}
		donec <- struct{}{}
	}()
	// wait for txn to fail on disconnect
	time.Sleep(100 * time.Millisecond)

	// restart node; client should resume
	clus.Members[0].Restart(t)
	select {
	case <-donec:
	case <-time.After(5 * time.Second):
		t.Fatalf("waited too long")
	}
}

func TestTxnWriteFail(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{Size: 3})
	defer clus.Terminate(t)

	kv := clientv3.NewKV(clus.Client(0))
	ctx := context.TODO()

	clus.Members[0].Stop(t)
	<-clus.Members[0].StopNotify()

	donec := make(chan struct{})
	go func() {
		resp, err := kv.Txn(ctx).Then(clientv3.OpPut("foo", "bar")).Commit()
		if err == nil {
			t.Fatalf("expected error, got response %v", resp)
		}
		donec <- struct{}{}
	}()

	dialTimeout := 5 * time.Second
	select {
	case <-time.After(2*dialTimeout + time.Second):
		t.Fatalf("timed out waiting for txn to fail")
	case <-donec:
		// don't restart cluster until txn errors out
	}

	go func() {
		// reconnect so terminate doesn't complain about double-close
		clus.Members[0].Restart(t)
		// wait for etcdserver to get established (CI races and get req times out)
		time.Sleep(2 * time.Second)
		donec <- struct{}{}

		// and ensure the put didn't take
		gresp, gerr := kv.Get(ctx, "foo")
		if gerr != nil {
			t.Fatal(gerr)
		}
		if len(gresp.Kvs) != 0 {
			t.Fatalf("expected no keys, got %v", gresp.Kvs)
		}
		donec <- struct{}{}
	}()

	select {
	case <-time.After(5 * time.Second):
		t.Fatalf("timed out waiting for restart")
	case <-donec:
	}

	select {
	case <-time.After(5 * time.Second):
		t.Fatalf("timed out waiting for get")
	case <-donec:
	}
}

func NewDoubleBarrier(client *clientv3.Client, key string, count int) *DoubleBarrier {
	return &DoubleBarrier{
		client: client,
		kv:     clientv3.NewKV(client),
		ctx:    context.TODO(),
		key:    key,
		count:  count,
	}
}

func (s *syncer) SyncBase(ctx context.Context) (<-chan clientv3.GetResponse, chan error) {
	respchan := make(chan clientv3.GetResponse, 1024)
	errchan := make(chan error, 1)

	kapi := clientv3.NewKV(s.c)
	// if rev is not specified, we will choose the most recent revision.
	if s.rev == 0 {
		resp, err := kapi.Get(ctx, "foo")
		if err != nil {
			errchan <- err
			close(respchan)
			close(errchan)
			return respchan, errchan
		}
		s.rev = resp.Header.Revision
	}

	go func() {
		defer close(respchan)
		defer close(errchan)

		var key string

		opts := []clientv3.OpOption{clientv3.WithLimit(batchLimit), clientv3.WithRev(s.rev)}

		if len(s.prefix) == 0 {
			// If len(s.prefix) == 0, we will sync the entire key-value space.
			// We then range from the smallest key (0x00) to the end.
			opts = append(opts, clientv3.WithFromKey())
			key = "\x00"
		} else {
			// If len(s.prefix) != 0, we will sync key-value space with given prefix.
			// We then range from the prefix to the next prefix if exists. Or we will
			// range from the prefix to the end if the next prefix does not exists.
			opts = append(opts, clientv3.WithPrefix())
			key = s.prefix
		}

		for {
			resp, err := kapi.Get(ctx, key, opts...)
			if err != nil {
				errchan <- err
				return
			}

			respchan <- (clientv3.GetResponse)(*resp)

			if !resp.More {
				return
			}
			// move to next key
			key = string(append(resp.Kvs[len(resp.Kvs)-1].Key, 0))
		}
	}()

	return respchan, errchan
}

// delCommandFunc executes the "del" command.
func delCommandFunc(cmd *cobra.Command, args []string) {
	key, opts := getDelOp(cmd, args)
	c := mustClientFromCmd(cmd)
	kvapi := clientv3.NewKV(c)
	resp, err := kvapi.Delete(context.TODO(), key, opts...)
	if err != nil {
		ExitWithError(ExitError, err)
	}
	display.Del(*resp)
}

// putCommandFunc executes the "put" command.
func putCommandFunc(cmd *cobra.Command, args []string) {
	key, value, opts := getPutOp(cmd, args)

	c := mustClientFromCmd(cmd)
	kvapi := clientv3.NewKV(c)
	resp, err := kvapi.Put(context.TODO(), key, value, opts...)
	if err != nil {
		ExitWithError(ExitError, err)
	}
	display.Put(*resp)
}