// Copyright 2023 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.

// These tests are directly validating etcd connection multiplexing.
//go:build !cluster_proxy

package e2e

import (
	"context"
	"encoding/json"
	"fmt"
	"syscall"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"

	clientv2 "go.etcd.io/etcd/client"
	pb "go.etcd.io/etcd/etcdserver/etcdserverpb"
	"go.etcd.io/etcd/pkg/testutil"
)

func TestConnectionMultiplexing(t *testing.T) {
	defer testutil.AfterTest(t)
	for _, tc := range []struct {
		name             string
		serverTLS        clientConnType
		separateHttpPort bool
	}{
		{
			name:      "ServerTLS",
			serverTLS: clientTLS,
		},
		{
			name:      "ServerNonTLS",
			serverTLS: clientNonTLS,
		},
		{
			name:      "ServerTLSAndNonTLS",
			serverTLS: clientTLSAndNonTLS,
		},
		{
			name:             "SeparateHTTP/ServerTLS",
			serverTLS:        clientTLS,
			separateHttpPort: true,
		},
		{
			name:             "SeparateHTTP/ServerNonTLS",
			serverTLS:        clientNonTLS,
			separateHttpPort: true,
		},
	} {
		t.Run(tc.name, func(t *testing.T) {
			ctx := context.Background()
			cfg := etcdProcessClusterConfig{
				clusterSize:        1,
				clientTLS:          tc.serverTLS,
				enableV2:           true,
				clientHttpSeparate: tc.separateHttpPort,
				stopSignal:         syscall.SIGTERM, // check graceful stop
			}
			clus, err := newEtcdProcessCluster(&cfg)
			require.NoError(t, err)

			defer func() {
				require.NoError(t, clus.Close())
			}()

			var clientScenarios []clientConnType
			switch tc.serverTLS {
			case clientTLS:
				clientScenarios = []clientConnType{clientTLS}
			case clientNonTLS:
				clientScenarios = []clientConnType{clientNonTLS}
			case clientTLSAndNonTLS:
				clientScenarios = []clientConnType{clientTLS, clientNonTLS}
			}

			for _, connType := range clientScenarios {
				name := "ClientNonTLS"
				if connType == clientTLS {
					name = "ClientTLS"
				}
				t.Run(name, func(t *testing.T) {
					testConnectionMultiplexing(ctx, t, clus.procs[0], connType)
				})
			}
		})
	}
}

func testConnectionMultiplexing(ctx context.Context, t *testing.T, member etcdProcess, connType clientConnType) {
	httpEndpoint := member.EndpointsHTTP()[0]
	grpcEndpoint := member.EndpointsGRPC()[0]
	switch connType {
	case clientTLS:
		httpEndpoint = toTLS(httpEndpoint)
		grpcEndpoint = toTLS(grpcEndpoint)
	case clientNonTLS:
	default:
		panic(fmt.Sprintf("Unsupported conn type %v", connType))
	}
	t.Run("etcdctl", func(t *testing.T) {
		t.Run("v2", func(t *testing.T) {
			etcdctl := NewEtcdctl([]string{httpEndpoint}, connType, false, true)
			err := etcdctl.Set("a", "1")
			assert.NoError(t, err)
		})
		t.Run("v3", func(t *testing.T) {
			etcdctl := NewEtcdctl([]string{grpcEndpoint}, connType, false, false)
			err := etcdctl.Put("a", "1")
			assert.NoError(t, err)
		})
	})
	t.Run("clientv2", func(t *testing.T) {
		c, err := newClientV2(t, []string{httpEndpoint}, connType, false)
		require.NoError(t, err)
		kv := clientv2.NewKeysAPI(c)
		_, err = kv.Set(ctx, "a", "1", nil)
		assert.NoError(t, err)
	})
	t.Run("clientv3", func(t *testing.T) {
		c := newClient(t, []string{grpcEndpoint}, connType, false)
		_, err := c.Get(ctx, "a")
		assert.NoError(t, err)
	})
	t.Run("curl", func(t *testing.T) {
		for _, httpVersion := range []string{"2", "1.1", "1.0", ""} {
			tname := "http" + httpVersion
			if httpVersion == "" {
				tname = "default"
			}
			t.Run(tname, func(t *testing.T) {
				assert.NoError(t, fetchGrpcGateway(httpEndpoint, httpVersion, connType))
				assert.NoError(t, fetchMetrics(httpEndpoint, httpVersion, connType))
				assert.NoError(t, fetchVersion(httpEndpoint, httpVersion, connType))
				assert.NoError(t, fetchHealth(httpEndpoint, httpVersion, connType))
				assert.NoError(t, fetchDebugVars(httpEndpoint, httpVersion, connType))
			})
		}
	})
}

func fetchGrpcGateway(endpoint string, httpVersion string, connType clientConnType) error {
	rangeData, err := json.Marshal(&pb.RangeRequest{
		Key: []byte("a"),
	})
	if err != nil {
		return err
	}
	req := cURLReq{endpoint: "/v3/kv/range", value: string(rangeData), timeout: 5, httpVersion: httpVersion}
	return curl(endpoint, "POST", req, connType, "header")
}

func fetchMetrics(endpoint string, httpVersion string, connType clientConnType) error {
	req := cURLReq{endpoint: "/metrics", timeout: 5, httpVersion: httpVersion}
	return curl(endpoint, "GET", req, connType, "etcd_cluster_version")
}

func fetchVersion(endpoint string, httpVersion string, connType clientConnType) error {
	req := cURLReq{endpoint: "/version", timeout: 5, httpVersion: httpVersion}
	return curl(endpoint, "GET", req, connType, "etcdserver")
}

func fetchHealth(endpoint string, httpVersion string, connType clientConnType) error {
	req := cURLReq{endpoint: "/health", timeout: 5, httpVersion: httpVersion}
	return curl(endpoint, "GET", req, connType, "health")
}

func fetchDebugVars(endpoint string, httpVersion string, connType clientConnType) error {
	req := cURLReq{endpoint: "/debug/vars", timeout: 5, httpVersion: httpVersion}
	return curl(endpoint, "GET", req, connType, "file_descriptor_limit")
}

func curl(endpoint string, method string, curlReq cURLReq, connType clientConnType, expect string) error {
	args := cURLPrefixArgs(endpoint, connType, false, method, curlReq)
	return spawnWithExpect(args, expect)
}