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/
chat.go
116 lines (101 loc) · 2.45 KB
/
chat.go
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package main
import (
"bufio"
"fmt"
"io"
"log"
"net"
"os"
"strings"
)
type Client struct {
conn net.Conn
nickname string
ch chan string
}
func main() {
ln, err := net.Listen("tcp", ":6000")
if err != nil {
fmt.Println(err)
os.Exit(1)
}
msgchan := make(chan string)
addchan := make(chan Client)
rmchan := make(chan Client)
go handleMessages(msgchan, addchan, rmchan)
for {
conn, err := ln.Accept()
if err != nil {
fmt.Println(err)
continue
}
go handleConnection(conn, msgchan, addchan, rmchan)
}
}
func (c Client) ReadLinesInto(ch chan<- string) {
bufc := bufio.NewReader(c.conn)
for {
line, err := bufc.ReadString('\n')
if err != nil {
break
}
ch <- fmt.Sprintf("%s: %s", c.nickname, line)
}
}
func (c Client) WriteLinesFrom(ch <-chan string) {
for msg := range ch {
_, err := io.WriteString(c.conn, msg)
if err != nil {
return
}
}
}
func promptNick(c net.Conn, bufc *bufio.Reader) string {
io.WriteString(c, "\033[1;30;41mWelcome to the fancy demo chat!\033[0m\n")
io.WriteString(c, "What is your nick? ")
nick, _, _ := bufc.ReadLine()
return string(nick)
}
func handleConnection(c net.Conn, msgchan chan<- string, addchan chan<- Client, rmchan chan<- Client) {
bufc := bufio.NewReader(c)
defer c.Close()
client := Client{
conn: c,
nickname: promptNick(c, bufc),
ch: make(chan string),
}
if strings.TrimSpace(client.nickname) == "" {
io.WriteString(c, "Invalid Username\n")
return
}
// Register user
addchan <- client
defer func() {
msgchan <- fmt.Sprintf("User %s left the chat room.\n", client.nickname)
log.Printf("Connection from %v closed.\n", c.RemoteAddr())
rmchan <- client
}()
io.WriteString(c, fmt.Sprintf("Welcome, %s!\n\n", client.nickname))
msgchan <- fmt.Sprintf("New user %s has joined the chat room.\n", client.nickname)
// I/O
go client.ReadLinesInto(msgchan)
client.WriteLinesFrom(client.ch)
}
func handleMessages(msgchan <-chan string, addchan <-chan Client, rmchan <-chan Client) {
clients := make(map[net.Conn]chan<- string)
for {
select {
case msg := <-msgchan:
log.Printf("New message: %s", msg)
for _, ch := range clients {
go func(mch chan<- string) { mch <- "\033[1;33;40m" + msg + "\033[m" }(ch)
}
case client := <-addchan:
log.Printf("New client: %v\n", client.conn)
clients[client.conn] = client.ch
case client := <-rmchan:
log.Printf("Client disconnects: %v\n", client.conn)
delete(clients, client.conn)
}
}
}