3 files changed, 158 insertions, 0 deletions
diff --git a/chat/buddy.go b/chat/buddy.go
new file mode 100644
index 0000000..c6f07ad
--- /dev/null
+++ b/chat/buddy.go
@@ -0,0 +1,41 @@
+package chat
+
+import (
+	"time"
+)
+
+type Buddy struct {
+	Nick    string
+	Receive chan Message
+	room    *Room
+}
+
+func NewBuddy(nick string, room *Room) *Buddy {
+	return &Buddy{
+		Nick:    nick,
+		Receive: make(chan Message),
+		room:    room,
+	}
+}
+
+func (b *Buddy) Leave() {
+	b.room.Leave(b.Nick)
+}
+
+func (b *Buddy) Push(msg Message) {
+	go func() {
+		select {
+		case b.Receive <- msg:
+		case <-time.Tick(time.Millisecond * 100):
+		}
+	}()
+}
+
+// Say sends a text as a chat message of this user to the connected room.
+func (b *Buddy) Say(text string) {
+	b.room.Messages <- Message{
+		Type: MsgChat,
+		User: b.Nick,
+		Text: text,
+	}
+}
diff --git a/chat/messages.go b/chat/messages.go
new file mode 100644
index 0000000..793fc6c
--- /dev/null
+++ b/chat/messages.go
@@ -0,0 +1,33 @@
+package chat
+
+import (
+	"encoding/json"
+	"errors"
+)
+
+type MsgType int
+
+const (
+	MsgChat MsgType = iota // Default
+	MsgJoin
+	MsgLeave
+)
+
+func (mt *MsgType) MarshalJSON() ([]byte, error) {
+	switch *mt {
+	case MsgChat:
+		return json.Marshal("chat")
+	case MsgJoin:
+		return json.Marshal("join")
+	case MsgLeave:
+		return json.Marshal("leave")
+	}
+
+	return nil, errors.New("Unknown message type")
+}
+
+type Message struct {
+	Type MsgType `json:"type"`
+	User string  `json:"user"`
+	Text string  `json:"text,omitempty"`
+}
diff --git a/chat/rooms.go b/chat/rooms.go
new file mode 100644
index 0000000..e954e29
--- /dev/null
+++ b/chat/rooms.go
@@ -0,0 +1,84 @@
+package chat
+
+import (
+	"errors"
+)
+
+type Room struct {
+	Messages chan Message
+	Buddies  map[string]*Buddy
+}
+
+func NewRoom() (r *Room) {
+	r = new(Room)
+	r.Messages = make(chan Message)
+	r.Buddies = make(map[string]*Buddy)
+	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)
+	} else {
+		r.Messages <- Message{
+			Type: MsgLeave,
+			User: nick,
+		}
+	}
+}
+
+func (r *Room) Broadcast() {
+	for m := range r.Messages {
+		for _, buddy := range r.Buddies {
+			buddy.Push(m)
+		}
+	}
+}
+
+func (r *Room) ListBuddies() (buddies []string) {
+	for nick := range r.Buddies {
+		buddies = append(buddies, nick)
+	}
+	return
+}
+
+var (
+	rooms   map[string]*Room
+	perroom int
+)
+
+func InitRooms(room_limit int) {
+	rooms = make(map[string]*Room)
+	perroom = room_limit
+}
+
+func Join(room, nick string) (*Buddy, *Room, error) {
+	r, ok := rooms[room]
+	if !ok {
+		r = NewRoom()
+		rooms[room] = r
+	}
+
+	if _, there := r.Buddies[nick]; there {
+		return nil, nil, errors.New("Nickname is already in use")
+	}
+
+	if len(r.Buddies) >= perroom {
+		return nil, nil, errors.New("Room is full")
+	}
+
+	r.Messages <- Message{
+		Type: MsgJoin,
+		User: nick,
+	}
+
+	b := NewBuddy(nick, r)
+	r.Buddies[nick] = b
+	return b, r, nil
+}