commit 7b1c126acd47955ef5a952c6bf898d0be163bf4a
Author: kenneth <lyydhl.03280324.zhang@outlook.com>
Date:   Sun Dec 24 00:10:41 2023 +0800

    first commit

diff --git a/README.md b/README.md
new file mode 100644
index 0000000..fd2d928
--- /dev/null
+++ b/README.md
@@ -0,0 +1,7 @@
+# TCP CHAT
+
++ `/nick <name>` 设置自己的昵称
++ `/join <room>` 加入聊天房间
++ `/rooms` 获取聊天房间列表
++ `/msg <msg>` 发送消息
++ `/quit` 退出房间
\ No newline at end of file
diff --git a/client.go b/client.go
new file mode 100644
index 0000000..9db2879
--- /dev/null
+++ b/client.go
@@ -0,0 +1,71 @@
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+	"strings"
+)
+
+type client struct {
+	conn     net.Conn
+	nick     string
+	room     *room
+	commands chan<- command
+}
+
+func (c *client) readInput() {
+	for {
+		msg, err := bufio.NewReader(c.conn).ReadString('\n')
+		if err != nil {
+			return
+		}
+
+		msg = strings.Trim(msg, "\r\n")
+		args := strings.Split(msg, " ")
+		cmd := strings.TrimSpace(args[0])
+
+		switch cmd {
+		case "/nick":
+			c.commands <- command{
+				id:     CMD_NICK,
+				client: c,
+				args:   args,
+			}
+		case "/join":
+			c.commands <- command{
+				id:     CMD_JOIN,
+				client: c,
+				args:   args,
+			}
+		case "/rooms":
+			c.commands <- command{
+				id:     CMD_ROOMS,
+				client: c,
+				args:   args,
+			}
+		case "/msg":
+			c.commands <- command{
+				id:     CMD_MSG,
+				client: c,
+				args:   args,
+			}
+		case "/quit":
+			c.commands <- command{
+				id:     CMD_QUIT,
+				client: c,
+				args:   args,
+			}
+		default:
+			c.err(fmt.Errorf("unknown command %s", cmd))
+		}
+	}
+}
+
+func (c *client) err(err error) {
+	c.conn.Write([]byte("ERR: " + err.Error() + "\n"))
+}
+
+func (c *client) msg(msg string) {
+	c.conn.Write([]byte("> " + msg + "\n"))
+}
diff --git a/command.go b/command.go
new file mode 100644
index 0000000..0ffcdff
--- /dev/null
+++ b/command.go
@@ -0,0 +1,17 @@
+package main
+
+type commandId int
+
+const (
+	CMD_NICK = iota
+	CMD_JOIN
+	CMD_ROOMS
+	CMD_MSG
+	CMD_QUIT
+)
+
+type command struct {
+	id     commandId
+	client *client
+	args   []string
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..92197e6
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,3 @@
+module github.com/zhang2092/tcp-chat
+
+go 1.21.4
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..6847b05
--- /dev/null
+++ b/main.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"log"
+	"net"
+)
+
+func main() {
+	s := newServer()
+	go s.run()
+
+	linstener, err := net.Listen("tcp", ":8888")
+	if err != nil {
+		log.Fatalf("failed to start server: %v", err)
+	}
+	defer linstener.Close()
+	log.Println("started server on :8888")
+
+	for {
+		conn, err := linstener.Accept()
+		if err != nil {
+			log.Printf("failed to accept connection: %v", err)
+			continue
+		}
+
+		go s.newClient(conn)
+	}
+}
diff --git a/room.go b/room.go
new file mode 100644
index 0000000..13e444a
--- /dev/null
+++ b/room.go
@@ -0,0 +1,16 @@
+package main
+
+import "net"
+
+type room struct {
+	name    string
+	members map[net.Addr]*client
+}
+
+func (r *room) broadcast(c *client, msg string) {
+	for addr, m := range r.members {
+		if addr != c.conn.RemoteAddr() {
+			m.msg(msg)
+		}
+	}
+}
diff --git a/server.go b/server.go
new file mode 100644
index 0000000..b132940
--- /dev/null
+++ b/server.go
@@ -0,0 +1,109 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"strings"
+)
+
+type server struct {
+	rooms    map[string]*room
+	commands chan command
+}
+
+func newServer() *server {
+	return &server{
+		rooms:    make(map[string]*room),
+		commands: make(chan command),
+	}
+}
+
+func (s *server) run() {
+	for cmd := range s.commands {
+		switch cmd.id {
+		case CMD_NICK:
+			s.nick(cmd.client, cmd.args)
+		case CMD_JOIN:
+			s.join(cmd.client, cmd.args)
+		case CMD_ROOMS:
+			s.listRooms(cmd.client, cmd.args)
+		case CMD_MSG:
+			s.msg(cmd.client, cmd.args)
+		case CMD_QUIT:
+			s.quit(cmd.client, cmd.args)
+		}
+	}
+}
+
+func (s *server) newClient(conn net.Conn) {
+	log.Printf("new client has connected: %s", conn.RemoteAddr().String())
+
+	c := &client{
+		conn:     conn,
+		nick:     "anonymous",
+		commands: s.commands,
+	}
+
+	c.readInput()
+}
+
+func (s *server) nick(c *client, args []string) {
+	c.nick = args[1]
+	c.msg(fmt.Sprintf("all right, I will call you %s", c.nick))
+}
+
+func (s *server) join(c *client, args []string) {
+	roomName := args[1]
+
+	r, ok := s.rooms[roomName]
+	if !ok {
+		r = &room{
+			name:    roomName,
+			members: make(map[net.Addr]*client),
+		}
+		s.rooms[roomName] = r
+	}
+
+	r.members[c.conn.RemoteAddr()] = c
+
+	s.quitCurrentRoom(c)
+	c.room = r
+
+	r.broadcast(c, fmt.Sprintf("%s has joined the room", c.nick))
+	c.msg(fmt.Sprintf("Wecome to %s", r.name))
+}
+
+func (s *server) listRooms(c *client, args []string) {
+	var rooms []string
+	for name := range s.rooms {
+		rooms = append(rooms, name)
+	}
+
+	c.msg(fmt.Sprintf("available rooms are: %s", strings.Join(rooms, ", ")))
+}
+
+func (s *server) msg(c *client, args []string) {
+	if c.room == nil {
+		c.err(errors.New("you must join the room first"))
+		return
+	}
+
+	c.room.broadcast(c, strings.Join(args[1:], " "))
+}
+
+func (s *server) quit(c *client, args []string) {
+	log.Printf("client has disconnection: %s", c.conn.RemoteAddr().String())
+
+	s.quitCurrentRoom(c)
+	c.msg("sad to see you go :(")
+	c.conn.Close()
+}
+
+func (s *server) quitCurrentRoom(c *client) {
+	if c.room != nil {
+		delete(c.room.members, c.conn.RemoteAddr())
+		c.room.broadcast(c, fmt.Sprintf("%s has left the room", c.nick))
+	}
+}