package scenarios

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

	"v2ray.com/core"
	"v2ray.com/core/app/log"
	"v2ray.com/core/app/policy"
	"v2ray.com/core/app/proxyman"
	clog "v2ray.com/core/common/log"
	"v2ray.com/core/common/net"
	"v2ray.com/core/common/protocol"
	"v2ray.com/core/common/serial"
	"v2ray.com/core/common/uuid"
	"v2ray.com/core/proxy/dokodemo"
	"v2ray.com/core/proxy/freedom"
	"v2ray.com/core/proxy/vmess"
	"v2ray.com/core/proxy/vmess/inbound"
	"v2ray.com/core/proxy/vmess/outbound"
	"v2ray.com/core/testing/servers/tcp"
	. "v2ray.com/ext/assert"
)

func startQuickClosingTCPServer() (net.Listener, error) {
	listener, err := net.Listen("tcp", "127.0.0.1:0")
	if err != nil {
		return nil, err
	}
	go func() {
		for {
			conn, err := listener.Accept()
			if err != nil {
				break
			}
			b := make([]byte, 1024)
			conn.Read(b)
			conn.Close()
		}
	}()
	return listener, nil
}

func TestVMessClosing(t *testing.T) {
	assert := With(t)

	tcpServer, err := startQuickClosingTCPServer()
	assert(err, IsNil)
	defer tcpServer.Close()

	dest := net.DestinationFromAddr(tcpServer.Addr())

	userID := protocol.NewID(uuid.New())
	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&policy.Config{
				Level: map[uint32]*policy.Policy{
					0: {
						Timeout: &policy.Policy_Timeout{
							UplinkOnly:   &policy.Second{Value: 0},
							DownlinkOnly: &policy.Second{Value: 0},
						},
					},
				},
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&inbound.Config{
					User: []*protocol.User{
						{
							Account: serial.ToTypedMessage(&vmess.Account{
								Id:      userID.String(),
								AlterId: 64,
							}),
						},
					},
				}),
			},
		},
		Outbound: []*core.OutboundHandlerConfig{
			{
				ProxySettings: serial.ToTypedMessage(&freedom.Config{}),
			},
		},
	}

	clientPort := tcp.PickPort()
	clientConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&policy.Config{
				Level: map[uint32]*policy.Policy{
					0: {
						Timeout: &policy.Policy_Timeout{
							UplinkOnly:   &policy.Second{Value: 0},
							DownlinkOnly: &policy.Second{Value: 0},
						},
					},
				},
			}),
		},
		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(&outbound.Config{
					Receiver: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: serial.ToTypedMessage(&vmess.Account{
										Id:      userID.String(),
										AlterId: 64,
										SecuritySettings: &protocol.SecurityConfig{
											Type: protocol.SecurityType_AES128_GCM,
										},
									}),
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	assert(err, IsNil)

	defer CloseAllServers(servers)

	conn, err := net.DialTCP("tcp", nil, &net.TCPAddr{
		IP:   []byte{127, 0, 0, 1},
		Port: int(clientPort),
	})
	assert(err, IsNil)

	conn.SetDeadline(time.Now().Add(time.Second * 2))

	nBytes, err := conn.Write([]byte("test payload"))
	assert(nBytes, GreaterThan, 0)
	assert(err, IsNil)

	resp := make([]byte, 1024)
	nBytes, err = conn.Read(resp)
	assert(err, Equals, io.EOF)
	assert(nBytes, Equals, 0)

	CloseAllServers(servers)
}

func TestZeroBuffer(t *testing.T) {
	assert := With(t)

	tcpServer := tcp.Server{
		MsgProcessor: xor,
	}
	dest, err := tcpServer.Start()
	assert(err, IsNil)
	defer tcpServer.Close()

	userID := protocol.NewID(uuid.New())
	serverPort := tcp.PickPort()
	serverConfig := &core.Config{
		App: []*serial.TypedMessage{
			serial.ToTypedMessage(&policy.Config{
				Level: map[uint32]*policy.Policy{
					0: {
						Timeout: &policy.Policy_Timeout{
							UplinkOnly:   &policy.Second{Value: 0},
							DownlinkOnly: &policy.Second{Value: 0},
						},
						Buffer: &policy.Policy_Buffer{
							Enabled: false,
						},
					},
				},
			}),
		},
		Inbound: []*core.InboundHandlerConfig{
			{
				ReceiverSettings: serial.ToTypedMessage(&proxyman.ReceiverConfig{
					PortRange: net.SinglePortRange(serverPort),
					Listen:    net.NewIPOrDomain(net.LocalHostIP),
				}),
				ProxySettings: serial.ToTypedMessage(&inbound.Config{
					User: []*protocol.User{
						{
							Account: serial.ToTypedMessage(&vmess.Account{
								Id:      userID.String(),
								AlterId: 64,
							}),
						},
					},
				}),
			},
		},
		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(&outbound.Config{
					Receiver: []*protocol.ServerEndpoint{
						{
							Address: net.NewIPOrDomain(net.LocalHostIP),
							Port:    uint32(serverPort),
							User: []*protocol.User{
								{
									Account: serial.ToTypedMessage(&vmess.Account{
										Id:      userID.String(),
										AlterId: 64,
										SecuritySettings: &protocol.SecurityConfig{
											Type: protocol.SecurityType_AES128_GCM,
										},
									}),
								},
							},
						},
					},
				}),
			},
		},
	}

	servers, err := InitializeServerConfigs(serverConfig, clientConfig)
	assert(err, IsNil)

	var wg sync.WaitGroup
	wg.Add(10)
	for i := 0; i < 10; i++ {
		go func() {
			conn, err := net.DialTCP("tcp", nil, &net.TCPAddr{
				IP:   []byte{127, 0, 0, 1},
				Port: int(clientPort),
			})
			assert(err, IsNil)

			payload := make([]byte, 10240*1024)
			rand.Read(payload)

			nBytes, err := conn.Write([]byte(payload))
			assert(err, IsNil)
			assert(nBytes, Equals, len(payload))

			response := readFrom(conn, time.Second*20, 10240*1024)
			assert(response, Equals, xor([]byte(payload)))
			assert(conn.Close(), IsNil)
			wg.Done()
		}()
	}
	wg.Wait()

	CloseAllServers(servers)
}