gistfile1.clj

(ns chat.channel
  (:use 
    [clojure.contrib.def]
    [chat.common]))

(defvar channels (agent {}))

(defn- list-users
  [channel]
  (map #(% :user-name) (@channel :users)))

(defn- write
  [channel message]
  (doseq [user (@channel :users)]
    (user :send :write message))
  nil)

(defn- say
  [channel user-name message]
  (write channel (str "message " (@channel :channel-name) " " user-name " " message)))

(defn- user-join
  [channel user-name]
  (write channel (str "join " (@channel :channel-name) " " user-name)))

(defn- leave
  [channel user-name]
  (write channel (str "leave " (@channel :channel-name) " " user-name)))

(defn dispatcher
  [state message & args]
  (cond 
    (= message :agent) state
    (= message :state) @state
    (= message :channel-name) (@state :channel-name)
    (= message :list-users) (apply list-users state args)
    (= message :join) (apply user-join state args)
    (= message :leave) (apply leave state args)
    (= message :say) (apply say state args)
    (= message :send)
      (do
        (apply chat.common/send-message state args)
        (partial dispatcher state))
    :else (throw (IllegalArgumentException. 
                   (str "unknown message in [" "channel" "] " message)))))

(defn- add-user
  [channel user]
  (conj channel {:users (conj (channel :users) user)}))

(defn create
  [channel-name]
  (let 
    [
     new-channel
     (partial dispatcher     
       (agent 
         {
          :channel-name channel-name 
          :users '()
          :add-user add-user
          }))]
    (send channels conj {channel-name new-channel})
    new-channel))

(defn delete-all
  []
  (defvar channels (agent {})))