finish budgetchat

cmd/budgetchat/client.go

@@ -0,0 +1,96 @@
+package main
+
+import (
+	"errors"
+	"fmt"
+	"log"
+	"net"
+	"regexp"
+	"strings"
+)
+
+type client struct {
+	c    net.Conn
+	name string
+}
+
+func isValidName(name string) bool {
+	pattern := "^[a-zA-Z0-9]+$"
+	nameReg, err := regexp.Compile(pattern)
+	if err != nil {
+		log.Fatalln(err)
+	}
+	return nameReg.MatchString(name)
+}
+
+func cleanString(buf []byte) string {
+	s := string(buf)
+	idx := strings.Index(s, "\n")
+	if idx != -1 {
+		s = s[:idx]
+	}
+	return s
+}
+
+func newClient(c net.Conn) (*client, error) {
+	cl := &client{
+		c:    c,
+		name: "",
+	}
+
+	cl.sendMessageString("Welcome to budgetchat! What shall I call you?")
+
+	r := make(chan string, 1)
+	var err error = nil
+	go func() {
+		for {
+			buf := make([]byte, 32)
+			_, err = c.Read(buf)
+			if err != nil {
+				c.Close()
+				r <- ""
+				return
+			}
+			name := cleanString(buf)
+
+			// Check legality
+			if !isValidName(name) {
+				cl.sendMessageString("The name %s is invalid", string(name))
+				err = errors.New("name invalid")
+				c.Close()
+				r <- name
+				return
+			}
+
+			// Check for duplicate name
+			for _, cls := range room {
+				if cls.name == name {
+					cl.sendMessageString("The name %s is already taken", string(name))
+					err = errors.New("name already taken")
+					c.Close()
+					r <- name
+					return
+				}
+			}
+			r <- name
+			return
+		}
+	}()
+
+	cl.name = <-r
+	if err != nil {
+		return nil, err
+	}
+	return cl, nil
+}
+
+func (cl *client) sendMessage(m []byte) {
+	_, err := cl.c.Write(m)
+	if err != nil {
+		log.Fatalln(err)
+	}
+}
+
+func (cl *client) sendMessageString(m string, vars ...any) {
+	cl.sendMessage([]byte(fmt.Sprintf(m, vars...) + "\n"))
+}

cmd/budgetchat/main.go

@@ -3,53 +3,83 @@ package main
 import (
 	"bufio"
 	"fmt"
+	"log"
 	"net"
-
 	"protohackers/pkg/conn"
 )
 
+type message struct {
+	msg    []byte
+	client *client
+}
+
+func msg(s string, c *client) message {
+	return message{[]byte(s), c}
+}
+
+var (
+	room     = make([]*client, 0)
+	messages = make(chan message, 32)
+)
+
 func main() {
-	l, err := net.Listen(conn.Type, conn.Port)
+	go broadcast()
+	err := conn.StartSimple(newUserHandler)
 	if err != nil {
-		panic(err)
+		log.Fatalln(err)
 	}
-	defer l.Close()
+}
 
-	fmt.Println(fmt.Sprintf("Listening on port %s", conn.Port))
-
-	r := createRoom()
+func broadcast() {
 	for {
-		c, err := l.Accept()
-		if err != nil {
+		select {
+		case m := <-messages:
+			for _, cl := range room {
+				if m.client == cl {
+					continue
+				}
+				cl.sendMessage(m.msg)
+			}
+		}
+	}
+}
+
+func userList() []byte {
+	m := "* The room contains: "
+	if len(room) > 0 {
+		for _, c := range room {
+			m += fmt.Sprintf("%s, ", c.name)
+		}
+		m = m[:len(m)-2]
+	}
+	return []byte(m + "\n")
+}
+
+func newUserHandler(c net.Conn) {
+	cl, err := newClient(c)
+	if err != nil {
+		return
+	}
+
+	cl.sendMessage(userList())
+	fmt.Printf("New client %s\n", cl.name)
+	messages <- msg(fmt.Sprintf("* %s has entered the room\n", cl.name), cl)
+	room = append(room, cl)
+
+	input := bufio.NewScanner(cl.c)
+	for input.Scan() {
+		m := fmt.Sprintf("[%s] %s\n", cl.name, input.Text())
+		messages <- msg(m, cl)
+	}
+
+	for i, p := range room {
+		if p == cl {
+			name := cl.name
+			cl.c.Close()
+			room = append(room[:i], room[i+1:]...)
+			fmt.Printf("%s has left", cl.name)
+			messages <- msg(fmt.Sprintf("* %s has left the room\n", name), cl)
 			break
 		}
-		go handleConn(r, c)
 	}
 }
-
-func handleConn(r *room, c net.Conn) {
-	u := newUser(c)
-	defer c.Close()
-	go u.sendMessage()
-
-	u.write("Welcome to budgetchat! What shall I call you?")
-
-	s := bufio.NewScanner(u.conn)
-	for s.Scan() {
-		input := s.Text()
-		if !u.online {
-			r.sendToRest(r.joinMsg(u), u)
-			u.write(r.connectMsg())
-			r.joinUser(u)
-		} else {
-			r.sendToRest(msgWrap(input, u), u)
-		}
-		if s.Err() != nil {
-			return
-		}
-	}
-}
-
-func msgWrap(msg string, u *user) string {
-	return fmt.Sprintf("[%s] %s", u.nick, msg)
-}

cmd/budgetchat/room.go

@@ -1,59 +0,0 @@
-package main
-
-import (
-	"fmt"
-	"strings"
-)
-
-type room struct {
-	users []*user
-}
-
-func createRoom() *room {
-	return &room{
-		users: make([]*user, 16),
-	}
-}
-
-func (r *room) joinUser(u *user) {
-	for _, usr := range r.users {
-		if usr.nick == u.nick {
-
-		}
-	}
-	r.users = append(r.users, u)
-	u.online = true
-}
-
-func (r *room) sendToAll(msg string) {
-	for _, u := range r.users {
-		if u.online {
-			u.write(msg)
-		}
-	}
-}
-
-func (r *room) sendToRest(msg string, skip *user) {
-	for _, u := range r.users {
-		if u.online && u != skip {
-			u.write(msg)
-		}
-	}
-}
-
-func (r *room) connected() (nicks []string) {
-	for _, u := range r.users {
-		if u.online {
-			nicks = append(nicks, u.nick)
-		}
-	}
-	return nicks
-}
-
-func (r *room) joinMsg(u *user) string {
-	return fmt.Sprintf("* %s has joined the channel", u.nick)
-}
-
-func (r *room) connectMsg() string {
-	return fmt.Sprintf("* The room contains: %s", strings.Join(r.connected(), ", "))
-}

cmd/budgetchat/user.go

@@ -1,27 +0,0 @@
-package main
-
-import "net"
-
-type user struct {
-	conn   net.Conn
-	nick   string
-	online bool
-	output chan string
-}
-
-func newUser(conn net.Conn) *user {
-	return &user{
-		conn:   conn,
-		output: make(chan string),
-	}
-}
-
-func (u *user) write(s string) {
-	u.output <- s + "\n"
-}
-
-func (u *user) sendMessage() {
-	for line := range u.output {
-		u.conn.Write([]byte(line))
-	}
-}

go.sum

@@ -0,0 +1,4 @@
+go.uber.org/multierr v1.11.0 h1:blXXJkSxSSfBVBlC76pxqeO+LN3aDfLQo+309xJstO0=
+go.uber.org/multierr v1.11.0/go.mod h1:20+QtiLqy0Nd6FdQB9TLXag12DsQkrbs3htMFfDN80Y=
+go.uber.org/zap v1.25.0 h1:4Hvk6GtkucQ790dqmj7l1eEnRdKm3k3ZUrUMS2d5+5c=
+go.uber.org/zap v1.25.0/go.mod h1:JIAUzQIH94IC4fOJQm7gMmBJP5k7wQfdcnYdPoEXJYk=