1 files changed, 46 insertions, 0 deletions
diff --git a/learn-you-some-erlang/m8ball/src/m8ball_server.erl b/learn-you-some-erlang/m8ball/src/m8ball_server.erl
new file mode 100644
index 0000000..4e821ad
--- /dev/null
+++ b/learn-you-some-erlang/m8ball/src/m8ball_server.erl
@@ -0,0 +1,46 @@
+-module(m8ball_server).
+-behaviour(gen_server).
+-export([start_link/0, stop/0, ask/1]).
+-export([init/1, handle_call/3, handle_cast/2, handle_info/2,
+         code_change/3, terminate/2]).
+
+%%%%%%%%%%%%%%%%%
+%%% INTERFACE %%%
+%%%%%%%%%%%%%%%%%
+start_link() ->
+    gen_server:start_link({global, ?MODULE}, ?MODULE, [], []).
+
+stop() ->
+    gen_server:call({global, ?MODULE}, stop).
+
+ask(_Question) -> % the question doesn't matter!
+    gen_server:call({global, ?MODULE}, question).
+
+%%%%%%%%%%%%%%%%%
+%%% CALLBACKS %%%
+%%%%%%%%%%%%%%%%%
+init([]) ->
+    <<A:32, B:32, C:32>> = crypto:rand_bytes(12),
+    random:seed(A,B,C),
+    {ok, []}.
+
+handle_call(question, _From, State) ->
+    {ok, Answers} = application:get_env(m8ball, answers),
+    Answer = element(random:uniform(tuple_size(Answers)), Answers),
+    {reply, Answer, State};
+handle_call(stop, _From, State) ->
+    {stop, normal, ok, State};
+handle_call(_Call, _From, State) ->
+    {noreply, State}.
+
+handle_cast(_Cast, State) ->
+    {noreply, State}.
+
+handle_info(_Info, State) ->
+    {noreply, State}.
+
+code_change(_OldVsn, State, _Extra) ->
+    {ok, State}.
+
+terminate(_Reason, _State) ->
+    ok.