// Copyright 2017 The etcd Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

// +build !cluster_proxy

package integration

import (
	"context"
	"testing"
	"time"

	"github.com/coreos/etcd/clientv3"
	"github.com/coreos/etcd/integration"
	"github.com/coreos/etcd/pkg/testutil"
)

// TestWatchKeepAlive tests when watch discovers it cannot talk to
// blackholed endpoint, client balancer switches to healthy one.
// TODO: test server-to-client keepalive ping
func TestWatchKeepAlive(t *testing.T) {
	defer testutil.AfterTest(t)

	clus := integration.NewClusterV3(t, &integration.ClusterConfig{
		Size:                 2,
		GRPCKeepAliveMinTime: 1 * time.Millisecond},
	) // avoid too_many_pings

	defer clus.Terminate(t)

	ccfg := clientv3.Config{
		Endpoints:            []string{clus.Members[0].GRPCAddr()},
		DialTimeout:          3 * time.Second,
		DialKeepAliveTime:    1 * time.Second,
		DialKeepAliveTimeout: 500 * time.Millisecond,
	}

	// gRPC internal implementation related.
	pingInterval := ccfg.DialKeepAliveTime + ccfg.DialKeepAliveTimeout
	timeout := pingInterval + 2*time.Second // 2s for slow machine to process watch and reset connections

	cli, err := clientv3.New(ccfg)
	if err != nil {
		t.Fatal(err)
	}
	defer cli.Close()

	wch := cli.Watch(context.Background(), "foo", clientv3.WithCreatedNotify())
	if _, ok := <-wch; !ok {
		t.Fatalf("watch failed on creation")
	}

	// endpoint can switch to ep[1] when it detects the failure of ep0
	cli.SetEndpoints(clus.Members[0].GRPCAddr(), clus.Members[1].GRPCAddr())

	clus.Members[0].Blackhole()

	if _, err = clus.Client(1).Put(context.TODO(), "foo", "bar"); err != nil {
		t.Fatal(err)
	}
	select {
	case <-wch:
	case <-time.After(timeout):
		t.Error("took too long to receive watch events")
	}

	clus.Members[0].Unblackhole()
	clus.Members[1].Blackhole()

	// make sure client0 can connect to member 0 after remove the blackhole.
	if _, err = clus.Client(0).Get(context.TODO(), "foo"); err != nil {
		t.Fatal(err)
	}

	if _, err = clus.Client(0).Put(context.TODO(), "foo", "bar1"); err != nil {
		t.Fatal(err)
	}
	select {
	case <-wch:
	case <-time.After(timeout):
		t.Error("took too long to receive watch events")
	}
}