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package chat
import (
"errors"
)
var (
NickAlreadyInUse = errors.New("Nickname is already in use")
RoomIsFull = errors.New("Room is full")
EmptyNick = errors.New("Nickname must not be empty")
NickTooLong = errors.New("NIckname is too long")
)
const (
nickLenLimit = 16
msgLenLimit = 2000
)
// Room represents a chatroom.
type Room struct {
messages chan Message
buddies map[string]*Buddy
name string
}
func newRoom(name string) (r *Room) {
r = new(Room)
r.messages = make(chan Message)
r.buddies = make(map[string]*Buddy)
r.name = name
go r.broadcast()
return
}
func (r *Room) leave(nick string) {
if _, ok := r.buddies[nick]; !ok {
return
}
delete(r.buddies, nick)
if len(r.buddies) == 0 {
close(r.messages)
delete(rooms, r.name)
} else {
r.messages <- Message{
Type: MsgLeave,
User: nick,
}
}
}
func (r *Room) broadcast() {
for m := range r.messages {
if len(m.Text) > msgLenLimit {
text := []rune(m.Text)
text = text[:msgLenLimit]
m.Text = string(text) + " (message truncated. was too long)"
}
for _, buddy := range r.buddies {
buddy.Push(m)
}
}
}
// ListBuddies returns a list of nicknames of the connected buddies.
func (r *Room) ListBuddies() (buddies []string) {
for nick := range r.buddies {
buddies = append(buddies, nick)
}
return
}
var (
rooms map[string]*Room
perroom int
)
// InitRooms initializes the internal rooms variable. Use this, before calling Join.
func InitRooms(room_limit int) {
rooms = make(map[string]*Room)
perroom = room_limit
}
// Join joins a buddy to a room. The room will be created, if it doesn't exist.
func Join(room, nick string) (*Buddy, *Room, error) {
r, ok := rooms[room]
if !ok {
r = newRoom(room)
rooms[room] = r
}
if _, there := r.buddies[nick]; there {
return nil, nil, NickAlreadyInUse
}
if nick == "" {
return nil, nil, EmptyNick
}
if len(nick) > nickLenLimit {
return nil, nil, NickTooLong
}
if len(r.buddies) >= perroom {
return nil, nil, RoomIsFull
}
r.messages <- Message{
Type: MsgJoin,
User: nick,
}
b := newBuddy(nick, r)
r.buddies[nick] = b
return b, r, nil
}
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