FlexDXCluster/TCPClient.go

package main

import (
	"bufio"
	"net"
	"os"
	"regexp"
	"strings"
	"sync"
	"time"

	log "github.com/sirupsen/logrus"
)

var spotRe *regexp.Regexp = regexp.MustCompile(`DX\sde\s([\w\d]+).*:\s+(\d+.\d)\s+([\w\d\/]+)\s+(CW|SSB|FT8|FT4|RTTY|USB|LSB)?\s+(.*)\s\s\s+([\d]+\w{1})`)
var defaultLoginRe *regexp.Regexp = regexp.MustCompile("[\\w\\d-_]+ login:")
var defaultPasswordRe *regexp.Regexp = regexp.MustCompile("Password:")

type TCPClient struct {
	Login                string
	Password             string
	Address              string
	Port                 string
	LoggedIn             bool
	Timeout              time.Duration
	LogWriter            *bufio.Writer
	Reader               *bufio.Reader
	Writer               *bufio.Writer
	Scanner              *bufio.Scanner
	Mutex                sync.Mutex
	Conn                 net.Conn
	TCPServer            TCPServer
	MsgChan              chan string
	CmdChan              chan string
	SpotChanToFlex       chan TelnetSpot
	SpotChanToHTTPServer chan TelnetSpot
	Log                  *log.Logger
	Config               *Config
	Countries            Countries
	LoginRe              *regexp.Regexp
	PasswordRe           *regexp.Regexp
}

func NewTCPClient(TCPServer *TCPServer, Countries Countries) *TCPClient {
	return &TCPClient{
		Address:              Cfg.Cluster.Server,
		Port:                 Cfg.Cluster.Port,
		Login:                Cfg.Cluster.Login,
		Password:             Cfg.Cluster.Password,
		MsgChan:              TCPServer.MsgChan,
		CmdChan:              TCPServer.CmdChan,
		SpotChanToFlex:       make(chan TelnetSpot, 100),
		TCPServer:            *TCPServer,
		SpotChanToHTTPServer: make(chan TelnetSpot, 100),
		Countries:            Countries,
	}
}

func (c *TCPClient) setDefaultParams() {
	if c.Timeout == 0 {
		c.Timeout = 600 * time.Second
	}
	if c.LogWriter == nil {
		c.LogWriter = bufio.NewWriter(os.Stdout)
	}
	c.LoggedIn = false

	if c.LoginRe == nil {
		c.LoginRe = defaultLoginRe
	}

	if c.PasswordRe == nil {
		c.PasswordRe = defaultPasswordRe
	}
}

func (c *TCPClient) StartClient() {
	var err error
	c.setDefaultParams()

	c.Conn, err = net.Dial("tcp", c.Address+":"+c.Port)
	if err != nil {
		Log.Error("Cannot connect to Telnet Client:", err)
	}

	c.Reader = bufio.NewReader(c.Conn)
	c.Writer = bufio.NewWriter(c.Conn)

	go func() {
		for message := range c.TCPServer.CmdChan {
			c.Mutex.Lock()
			Log.Infof("Received Command: %s", message)
			c.Write([]byte(message + "\r\n"))
			c.Mutex.Unlock()
		}
	}()

	go c.ReadLine()
}

func (c *TCPClient) Close() {
	c.Writer.WriteString("bye")
	time.Sleep(time.Second * 2)
}

func (c *TCPClient) SetFilters() {
	if Cfg.Cluster.FT8 {
		c.Mutex.Lock()
		c.Write([]byte("set/ft8\r\n"))
		Log.Info("FT8: On")
		c.Mutex.Unlock()
	}

	if Cfg.Cluster.Skimmer {
		c.Mutex.Lock()
		c.Write([]byte("set/skimmer\r\n"))
		Log.Info("Skimmer: On")
		c.Mutex.Unlock()
	}

	if Cfg.Cluster.FT4 {
		c.Mutex.Lock()
		c.Write([]byte("set/ft4\r\n"))
		Log.Info("FT4: On")
		c.Mutex.Unlock()
	}

	if !Cfg.Cluster.FT8 {
		c.Mutex.Lock()
		c.Write([]byte("set/noft8\r\n"))
		Log.Info("FT8: Off")
		c.Mutex.Unlock()
	}

	if !Cfg.Cluster.FT4 {
		c.Mutex.Lock()
		c.Write([]byte("set/noft4\r\n"))
		Log.Info("FT4: Off")
		c.Mutex.Unlock()
	}

	if !Cfg.Cluster.Skimmer {
		c.Mutex.Lock()
		c.Write([]byte("set/noskimmer\r\n"))
		Log.Info("Skimmer: Off")
		c.Mutex.Unlock()
	}
}

func (c *TCPClient) ReadLine() {

	for {

		if !c.LoggedIn {
			message, err := c.Reader.ReadBytes(':')
			if err != nil {
				Log.Errorf("Error reading message: %s", err)
				c.Conn.Close()
				c.StartClient()
			}

			if strings.Contains(string(message), Cfg.Cluster.LoginPrompt) || strings.Contains(string(message), "login:") {
				time.Sleep(time.Second * 1)
				Log.Debug("Found login prompt...sending callsign")
				c.Write([]byte(c.Login + "\n\r"))
				c.LoggedIn = true
				Log.Infof("Connected to DX cluster %s:%s", Cfg.Cluster.Server, Cfg.Cluster.Port)
				continue
			}
		}

		if c.LoggedIn {
			message, err := c.Reader.ReadBytes('\n')
			messageString := string(message)

			if messageString != "" {
				if err != nil {
					Log.Errorf("Error reading message: %s", err)
					c.Conn.Close()
					c.StartClient()
				}

				if strings.Contains(messageString, "password") {
					Log.Debug("Found password prompt...sending password...")
					c.Write([]byte(c.Password + "\r\n"))
				}

				if strings.Contains(messageString, "Hello") || strings.Contains(messageString, "Welcome") {
					go c.SetFilters()
					if Cfg.Cluster.Command != "" {
						c.WriteString(Cfg.Cluster.Command + "\n\r")
						Log.Debugf("Sending Command: %s", Cfg.Cluster.Command)
					}
				}

				if strings.Contains(messageString, "Error reading from server: read tcp") {
					Log.Error("Disconnected from Telnet Server, reconnecting")
					c.Close()
					c.StartClient()
				}

				if strings.Contains(messageString, "DX") {
					ProcessTelnetSpot(spotRe, messageString, c.SpotChanToFlex, c.SpotChanToHTTPServer, c.Countries)
				}

				// Send the spot message to TCP server
				c.MsgChan <- messageString
			}
		}
	}
}

// Write sends raw data to remove telnet server
func (tc *TCPClient) Write(data []byte) (n int, err error) {
	n, err = tc.Writer.Write(data)
	if err == nil {
		err = tc.Writer.Flush()
	}

	return
}

func (tc *TCPClient) WriteString(data string) (n int, err error) {
	n, err = tc.Writer.Write([]byte(data))
	if err == nil {
		err = tc.Writer.Flush()
	}

	return
}