From bcd354f77d27f01c4bb48c218e41664032091c46 Mon Sep 17 00:00:00 2001
From: Ery Lee <ery.lee@gmail.com>
Date: Thu, 12 Mar 2015 00:38:56 +0800
Subject: [PATCH] event manager

---
 apps/emqttd/src/emqttd_app.erl   |  1 +
 apps/emqttd/src/emqttd_event.erl | 91 +++++++++++++++++++++++++++++++-
 2 files changed, 90 insertions(+), 2 deletions(-)

diff --git a/apps/emqttd/src/emqttd_app.erl b/apps/emqttd/src/emqttd_app.erl
index e7dad3684..404591480 100644
--- a/apps/emqttd/src/emqttd_app.erl
+++ b/apps/emqttd/src/emqttd_app.erl
@@ -96,6 +96,7 @@ start_servers(Sup) ->
 			?PRINT_MSG("[done]~n")
 		end,
 	 	[{"emqttd config", emqttd_config},
+	 	 {"emqttd event", emqttd_event},
 		 {"emqttd server", emqttd_server, RetainOpts},
          {"emqttd client manager", emqttd_cm},
          {"emqttd session manager", emqttd_sm},
diff --git a/apps/emqttd/src/emqttd_event.erl b/apps/emqttd/src/emqttd_event.erl
index 1f2de5fb9..a2fa6fdf0 100644
--- a/apps/emqttd/src/emqttd_event.erl
+++ b/apps/emqttd/src/emqttd_event.erl
@@ -26,8 +26,95 @@
 %%%-----------------------------------------------------------------------------
 -module(emqttd_event).
 
--export([start_link/0]).
+-include("emqttd_packet.hrl").
 
+%% API Function Exports
+-export([start_link/0,
+         add_handler/2]).
+
+%% gen_event Function Exports
+-export([init/1,
+         handle_event/2,
+         handle_call/2,
+         handle_info/2,
+         terminate/2,
+         code_change/3]).
+
+-record(state, {systop}).
+
+%%------------------------------------------------------------------------------
+%% @doc
+%% Start emqttd event manager.
+%%
+%% @end
+%%------------------------------------------------------------------------------
+-spec start_link() -> {ok, pid()} | {error, any()}.
 start_link() ->
-    gen_event:start_link({local, ?MODULE}).
+    case gen_event:start_link({local, ?MODULE}) of
+        {ok, Pid} -> 
+            add_handler(?MODULE, []),
+            {ok, Pid};
+        {error, Reason} ->
+            {error, Reason}
+    end.
+
+add_handler(Handler, Args) ->
+    gen_event:add_handler(?MODULE, Handler, Args).
+
+%%%=============================================================================
+%%% gen_event callbacks
+%%%=============================================================================
+
+init([]) ->
+    SysTop = list_to_binary(lists:concat(["$SYS/brokers/", node()])),
+    {ok, #state{systop = SysTop}}.
+
+handle_event({connected, ClientId, Params}, State = #state{systop = SysTop}) ->
+    Topic = <<SysTop/binary, "clients/", ClientId/binary, "/connected">>,
+    Msg = #mqtt_message{topic = Topic, payload = payload(connected, Params)},
+    emqttd_pubsub:publish(Msg),
+    {ok, State};
+
+handle_event({disconnectd, ClientId, Reason}, State = #state{systop = SysTop}) ->
+    Topic = <<SysTop/binary, "clients/", ClientId/binary, "/disconnected">>,
+    Msg = #mqtt_message{topic = Topic, payload = payload(disconnected, Reason)},
+    emqttd_pubsub:publish(Msg),
+    {ok, State};
+
+handle_event({subscribed, ClientId, TopicTable}, State) ->
+    lager:error("TODO: subscribed ~s, ~p", [ClientId, TopicTable]),
+    {ok, State};
+
+handle_event({unsubscribed, ClientId, Topics}, State) ->
+    lager:error("TODO: unsubscribed ~s, ~p", [ClientId, Topics]),
+    {ok, State};
+
+handle_event(_Event, State) ->
+    {ok, State}.
+
+handle_call(_Request, State) ->
+    Reply = ok,
+    {ok, Reply, State}.
+
+handle_info(_Info, State) ->
+    {ok, State}.
+
+terminate(_Reason, _State) ->
+    ok.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+%% ------------------------------------------------------------------
+%% Internal Function Definitions
+%% ------------------------------------------------------------------
+
+payload(connected, Params) ->
+    From = proplists:get_value(from, Params),
+    Proto = proplists:get_value(protocol, Params),
+    Sess = proplists:get_value(session, Params),
+    iolist_to_binary(io_lib:format("from: ~s~nprotocol: ~p~nsession: ~s", [From, Proto, Sess]));
+
+payload(disconnected, Reason) ->
+    list_to_binary(lists:concat(["reason: ", Reason])).