package bridge

import (
	"encoding/binary"
	"errors"
	"github.com/cnlh/nps/lib/common"
	"github.com/cnlh/nps/lib/conn"
	"github.com/cnlh/nps/lib/crypt"
	"github.com/cnlh/nps/lib/file"
	"github.com/cnlh/nps/lib/kcp"
	"github.com/cnlh/nps/lib/lg"
	"github.com/cnlh/nps/lib/pool"
	"github.com/cnlh/nps/server/tool"
	"log"
	"net"
	"strconv"
	"sync"
	"time"
)

type Client struct {
	tunnel        *conn.Conn
	signal        *conn.Conn
	linkMap       map[int]*conn.Link
	linkStatusMap map[int]bool
	stop          chan bool
	sync.RWMutex
}

func NewClient(t *conn.Conn, s *conn.Conn) *Client {
	return &Client{
		linkMap:       make(map[int]*conn.Link),
		stop:          make(chan bool),
		linkStatusMap: make(map[int]bool),
		signal:        s,
		tunnel:        t,
	}
}

type Bridge struct {
	TunnelPort  int              //通信隧道端口
	tcpListener *net.TCPListener //server端监听
	kcpListener *kcp.Listener    //server端监听
	Client      map[int]*Client
	tunnelType  string //bridge type kcp or tcp
	OpenTask    chan *file.Tunnel
	CloseClient chan int
	lock        sync.Mutex
	tunnelLock  sync.Mutex
	clientLock  sync.RWMutex
}

func NewTunnel(tunnelPort int, tunnelType string) *Bridge {
	t := new(Bridge)
	t.TunnelPort = tunnelPort
	t.Client = make(map[int]*Client)
	t.tunnelType = tunnelType
	t.OpenTask = make(chan *file.Tunnel)
	t.CloseClient = make(chan int)
	return t
}

func (s *Bridge) StartTunnel() error {
	var err error
	if s.tunnelType == "kcp" {
		s.kcpListener, err = kcp.ListenWithOptions(":"+strconv.Itoa(s.TunnelPort), nil, 150, 3)
		if err != nil {
			return err
		}
		go func() {
			for {
				c, err := s.kcpListener.AcceptKCP()
				conn.SetUdpSession(c)
				if err != nil {
					lg.Println(err)
					continue
				}
				go s.cliProcess(conn.NewConn(c))
			}
		}()
	} else {
		s.tcpListener, err = net.ListenTCP("tcp", &net.TCPAddr{net.ParseIP("0.0.0.0"), s.TunnelPort, ""})
		if err != nil {
			return err
		}
		go func() {
			for {
				c, err := s.tcpListener.Accept()
				if err != nil {
					lg.Println(err)
					continue
				}
				go s.cliProcess(conn.NewConn(c))
			}
		}()
	}
	return nil
}

//验证失败，返回错误验证flag，并且关闭连接
func (s *Bridge) verifyError(c *conn.Conn) {
	c.Write([]byte(common.VERIFY_EER))
	c.Conn.Close()
}

func (s *Bridge) verifySuccess(c *conn.Conn) {
	c.Write([]byte(common.VERIFY_SUCCESS))
}

func (s *Bridge) cliProcess(c *conn.Conn) {
	c.SetReadDeadline(5, s.tunnelType)
	var buf []byte
	var err error
	if buf, err = c.ReadLen(32); err != nil {
		c.Close()
		return
	}
	//验证
	id, err := file.GetCsvDb().GetIdByVerifyKey(string(buf), c.Conn.RemoteAddr().String())
	if err != nil {
		lg.Println("当前客户端连接校验错误，关闭此客户端:", c.Conn.RemoteAddr())
		s.verifyError(c)
		return
	} else {
		s.verifySuccess(c)
	}
	//做一个判断 添加到对应的channel里面以供使用
	if flag, err := c.ReadFlag(); err == nil {
		s.typeDeal(flag, c, id)
	} else {
		log.Println(222)
		log.Println(err, flag)
	}
	return
}

func (s *Bridge) closeClient(id int) {
	s.clientLock.Lock()
	defer s.clientLock.Unlock()
	if v, ok := s.Client[id]; ok {
		if c, err := file.GetCsvDb().GetClient(id); err == nil && c.NoStore {
			s.CloseClient <- c.Id
		}
		v.signal.WriteClose()
		delete(s.Client, id)
	}
}

//tcp连接类型区分
func (s *Bridge) typeDeal(typeVal string, c *conn.Conn, id int) {
	switch typeVal {
	case common.WORK_MAIN:
		//客户端已经存在，下线
		s.clientLock.Lock()
		if v, ok := s.Client[id]; ok {
			s.clientLock.Unlock()
			if v.signal != nil {
				v.signal.WriteClose()
			}
			v.Lock()
			v.signal = c
			v.Unlock()
		} else {
			s.Client[id] = NewClient(nil, c)
			s.clientLock.Unlock()
		}
		lg.Printf("clientId %d connection succeeded, address:%s ", id, c.Conn.RemoteAddr())
		go s.GetStatus(id)
	case common.WORK_CHAN:
		s.clientLock.Lock()
		if v, ok := s.Client[id]; ok {
			s.clientLock.Unlock()
			v.Lock()
			v.tunnel = c
			v.Unlock()
		} else {
			s.Client[id] = NewClient(c, nil)
			s.clientLock.Unlock()
		}
		go s.clientCopy(id)
	case common.WORK_CONFIG:
		go s.GetConfig(c)
	}
	c.SetAlive(s.tunnelType)
	return
}

//等待
func (s *Bridge) waitStatus(clientId, id int) (bool) {
	ticker := time.NewTicker(time.Millisecond * 100)
	stop := time.After(time.Second * 10)
	for {
		select {
		case <-ticker.C:
			s.clientLock.Lock()
			if v, ok := s.Client[clientId]; ok {
				s.clientLock.Unlock()
				v.Lock()
				if vv, ok := v.linkStatusMap[id]; ok {
					ticker.Stop()
					v.Unlock()
					return vv
				}
				v.Unlock()
			} else {
				s.clientLock.Unlock()
			}
		case <-stop:
			return false
		}
	}
	return false
}

func (s *Bridge) SendLinkInfo(clientId int, link *conn.Link) (tunnel *conn.Conn, err error) {
	s.clientLock.Lock()
	if v, ok := s.Client[clientId]; ok {
		s.clientLock.Unlock()
		v.signal.SendLinkInfo(link)
		if err != nil {
			lg.Println("send link information error:", err, link.Id)
			s.DelClient(clientId)
			return
		}
		if v.tunnel == nil {
			err = errors.New("get tunnel connection error")
			return
		} else {
			tunnel = v.tunnel
		}
		v.Lock()
		v.linkMap[link.Id] = link
		v.Unlock()
		if !s.waitStatus(clientId, link.Id) {
			err = errors.New("connect fail")
			return
		}
	} else {
		s.clientLock.Unlock()
		err = errors.New("the connection is not connect")
	}
	return
}

//删除通信通道
func (s *Bridge) DelClient(id int) {
	s.closeClient(id)
}

//get config
func (s *Bridge) GetConfig(c *conn.Conn) {
	var client *file.Client
	var fail bool
	for {
		flag, err := c.ReadFlag()
		if err != nil {
			break
		}
		switch flag {
		case common.WORK_STATUS:
			if b, err := c.ReadLen(16); err != nil {
				break
			} else {
				var str string
				id, err := file.GetCsvDb().GetClientIdByVkey(string(b))
				if err != nil {
					break
				}
				for _, v := range file.GetCsvDb().Hosts {
					if v.Client.Id == id {
						str += v.Remark + common.CONN_DATA_SEQ
					}
				}
				for _, v := range file.GetCsvDb().Tasks {
					if v.Client.Id == id {
						str += v.Remark + common.CONN_DATA_SEQ
					}
				}
				binary.Write(c, binary.LittleEndian, int32(len([]byte(str))))
				binary.Write(c, binary.LittleEndian, []byte(str))
			}
		case common.NEW_CONF:
			//new client ,Set the client not to store to the file
			client = file.NewClient(crypt.GetRandomString(16), true, false)
			client.Remark = "public veky"
			//Send the key to the client
			file.GetCsvDb().NewClient(client)
			c.Write([]byte(client.VerifyKey))

			if config, err := c.GetConfigInfo(); err != nil {
				fail = true
				c.WriteAddFail()
				break
			} else {
				client.Cnf = config
				c.WriteAddOk()
			}
		case common.NEW_HOST:
			if h, err := c.GetHostInfo(); err != nil {
				fail = true
				c.WriteAddFail()
				break
			} else if file.GetCsvDb().IsHostExist(h.Host) {
				fail = true
				c.WriteAddFail()
			} else {
				h.Client = client
				file.GetCsvDb().NewHost(h)
				c.WriteAddOk()
			}
		case common.NEW_TASK:
			if t, err := c.GetTaskInfo(); err != nil {
				fail = true
				c.WriteAddFail()
				break
			} else {
				t.Client = client
				file.GetCsvDb().NewTask(t)
				if b := tool.TestServerPort(t.Port, t.Mode); !b {
					fail = true
					c.WriteAddFail()
				} else {
					s.OpenTask <- t
				}
				c.WriteAddOk()
			}
		}
	}
	if fail && client != nil {
		s.CloseClient <- client.Id
	}
	c.Close()
}

func (s *Bridge) GetStatus(clientId int) {
	s.clientLock.Lock()
	client := s.Client[clientId]
	s.clientLock.Unlock()

	if client == nil {
		return
	}
	for {
		if id, status, err := client.signal.GetConnStatus(); err != nil {
			s.closeClient(clientId)
			return
		} else {
			client.Lock()
			client.linkStatusMap[id] = status
			client.Unlock()
		}
	}
}

func (s *Bridge) clientCopy(clientId int) {

	s.clientLock.Lock()
	client := s.Client[clientId]
	s.clientLock.Unlock()

	for {
		if id, err := client.tunnel.GetLen(); err != nil {
			s.closeClient(clientId)
			lg.Println("读取msg id 错误", err, id)
			break
		} else {
			client.Lock()
			if link, ok := client.linkMap[id]; ok {
				client.Unlock()
				if content, err := client.tunnel.GetMsgContent(link); err != nil {
					pool.PutBufPoolCopy(content)
					s.closeClient(clientId)
					lg.Println("read msg content error", err, "close client")
					break
				} else {
					if len(content) == len(common.IO_EOF) && string(content) == common.IO_EOF {
						if link.Conn != nil {
							link.Conn.Close()
						}
					} else {
						if link.UdpListener != nil && link.UdpRemoteAddr != nil {
							link.UdpListener.WriteToUDP(content, link.UdpRemoteAddr)
						} else {
							link.Conn.Write(content)
						}
						link.Flow.Add(0, len(content))
					}
					pool.PutBufPoolCopy(content)
				}
			} else {
				client.Unlock()
				continue
			}
		}
	}
}