package scenarios

import (
	"crypto/rand"
	"testing"
	"time"

	"github.com/google/go-cmp/cmp"
	"golang.org/x/sync/errgroup"

	"v2ray.com/core"
	"v2ray.com/core/app/log"
	"v2ray.com/core/app/proxyman"
	"v2ray.com/core/common"
	"v2ray.com/core/common/errors"
	clog "v2ray.com/core/common/log"
	"v2ray.com/core/common/net"
	"v2ray.com/core/common/protocol"
	"v2ray.com/core/common/serial"
	"v2ray.com/core/proxy/dokodemo"
	"v2ray.com/core/proxy/freedom"
	"v2ray.com/core/proxy/shadowsocks"
	"v2ray.com/core/testing/servers/tcp"
	"v2ray.com/core/testing/servers/udp"
)

func TestShadowsocksAES256TCP(t *testing.T) {
	tcpServer := tcp.Server{
		MsgProcessor: xor,
	}
	dest, err := tcpServer.Start()
	common.Must(err)
	defer tcpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_AES_256_CFB,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_TCP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_TCP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)
	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(testTCPConn(clientPort, 10240*1024, time.Second*20))
	}
	if err := errg.Wait(); err != nil {
		t.Fatal(err)
	}
}

func TestShadowsocksAES128UDP(t *testing.T) {
	udpServer := udp.Server{
		MsgProcessor: xor,
	}
	dest, err := udpServer.Start()
	common.Must(err)
	defer udpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_AES_128_CFB,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_UDP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_UDP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)
	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(func() error {
			conn, err := net.DialUDP("udp", nil, &net.UDPAddr{
				IP:   []byte{127, 0, 0, 1},
				Port: int(clientPort),
			})
			if err != nil {
				return err
			}
			defer conn.Close()

			payload := make([]byte, 1024)
			common.Must2(rand.Read(payload))

			nBytes, err := conn.Write([]byte(payload))
			if err != nil {
				return err
			}
			if nBytes != len(payload) {
				return errors.New("expect ", len(payload), " written, but actually ", nBytes)
			}

			response := readFrom(conn, time.Second*5, 1024)
			if r := cmp.Diff(response, xor(payload)); r != "" {
				return errors.New(r)
			}
			return nil
		})
	}

	if err := errg.Wait(); err != nil {
		t.Fatal(err)
	}
}

func TestShadowsocksChacha20TCP(t *testing.T) {
	tcpServer := tcp.Server{
		MsgProcessor: xor,
	}
	dest, err := tcpServer.Start()
	common.Must(err)

	defer tcpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_CHACHA20_IETF,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_TCP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_TCP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)
	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(testTCPConn(clientPort, 10240*1024, time.Second*40))
	}

	if err := errg.Wait(); err != nil {
		t.Error(err)
	}
}

func TestShadowsocksChacha20Poly1305TCP(t *testing.T) {
	tcpServer := tcp.Server{
		MsgProcessor: xor,
	}
	dest, err := tcpServer.Start()
	common.Must(err)
	defer tcpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_CHACHA20_POLY1305,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_TCP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_TCP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)
	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(testTCPConn(clientPort, 10240*1024, time.Second*20))
	}
	if err := errg.Wait(); err != nil {
		t.Error(err)
	}
}

func TestShadowsocksAES256GCMTCP(t *testing.T) {
	tcpServer := tcp.Server{
		MsgProcessor: xor,
	}
	dest, err := tcpServer.Start()
	common.Must(err)
	defer tcpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_AES_256_GCM,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_TCP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_TCP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)
	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(testTCPConn(clientPort, 10240*1024, time.Second*20))
	}

	if err := errg.Wait(); err != nil {
		t.Error(err)
	}
}

func TestShadowsocksAES128GCMUDP(t *testing.T) {
	udpServer := udp.Server{
		MsgProcessor: xor,
	}
	dest, err := udpServer.Start()
	common.Must(err)
	defer udpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_AES_128_GCM,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_UDP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_UDP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)
	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(testUDPConn(clientPort, 1024, time.Second*5))
	}
	if err := errg.Wait(); err != nil {
		t.Error(err)
	}
}

func TestShadowsocksAES128GCMUDPMux(t *testing.T) {
	udpServer := udp.Server{
		MsgProcessor: xor,
	}
	dest, err := udpServer.Start()
	common.Must(err)
	defer udpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_AES_128_GCM,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_TCP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&log.Config{
				ErrorLogLevel: clog.Severity_Debug,
				ErrorLogType:  log.LogType_Console,
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_UDP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				SenderSettings: serial.ToTypedMessage(&proxyman.SenderConfig{
					MultiplexSettings: &proxyman.MultiplexingConfig{
						Enabled:     true,
						Concurrency: 8,
					},
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)
	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(testUDPConn(clientPort, 1024, time.Second*5))
	}
	if err := errg.Wait(); err != nil {
		t.Error(err)
	}
}

func TestShadowsocksNone(t *testing.T) {
	tcpServer := tcp.Server{
		MsgProcessor: xor,
	}
	dest, err := tcpServer.Start()
	common.Must(err)

	defer tcpServer.Close()

	account := serial.ToTypedMessage(&shadowsocks.Account{
		Password:   "shadowsocks-password",
		CipherType: shadowsocks.CipherType_NONE,
	})

	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ServerConfig{
					User: &protocol.User{
						Account: account,
						Level:   1,
					},
					Network: []net.Network{net.Network_TCP},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(clientPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&dokodemo.Config{
					Address: net.NewIPOrDomain(dest.Address),
					Port:    uint32(dest.Port),
					NetworkList: &net.NetworkList{
						Network: []net.Network{net.Network_TCP},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&shadowsocks.ClientConfig{
					Server: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: account,
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	common.Must(err)

	defer CloseAllServers(servers)

	var errg errgroup.Group
	for i := 0; i < 10; i++ {
		errg.Go(testTCPConn(clientPort, 10240*1024, time.Second*20))
	}

	if err := errg.Wait(); err != nil {
		t.Fatal(err)
	}
}
