1 files changed, 74 insertions, 0 deletions
diff --git a/learn-you-some-erlang/kitty_server.erl b/learn-you-some-erlang/kitty_server.erl
new file mode 100644
index 0000000..a40e20a
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+++ b/learn-you-some-erlang/kitty_server.erl
@@ -0,0 +1,74 @@
+%%%%% Naive version
+-module(kitty_server).
+
+-export([start_link/0, order_cat/4, return_cat/2, close_shop/1]).
+
+-record(cat, {name, color=green, description}).
+
+%%% Client API
+start_link() -> spawn_link(fun init/0).
+
+%% Synchronous call
+order_cat(Pid, Name, Color, Description) ->
+    Ref = erlang:monitor(process, Pid),
+    Pid ! {self(), Ref, {order, Name, Color, Description}},
+    receive
+        {Ref, Cat = #cat{}} ->
+            erlang:demonitor(Ref, [flush]),
+            Cat;
+        {'DOWN', Ref, process, Pid, Reason} ->
+            erlang:error(Reason)
+    after 5000 ->
+        erlang:error(timeout)
+    end.
+
+%% This call is asynchronous
+return_cat(Pid, Cat = #cat{}) ->
+    Pid ! {return, Cat},
+    ok.
+
+%% Synchronous call
+close_shop(Pid) ->
+    Ref = erlang:monitor(process, Pid),
+    Pid ! {self(), Ref, terminate},
+    receive
+        {Ref, ok} ->
+            erlang:demonitor(Ref, [flush]),
+            ok;
+        {'DOWN', Ref, process, Pid, Reason} ->
+            erlang:error(Reason)
+    after 5000 ->
+        erlang:error(timeout)
+    end.
+    
+%%% Server functions
+init() -> loop([]).
+
+loop(Cats) ->
+    receive
+        {Pid, Ref, {order, Name, Color, Description}} ->
+            if Cats =:= [] ->
+                Pid ! {Ref, make_cat(Name, Color, Description)},
+                loop(Cats); 
+               Cats =/= [] -> % got to empty the stock
+                Pid ! {Ref, hd(Cats)},
+                loop(tl(Cats))
+            end;
+        {return, Cat = #cat{}} ->
+            loop([Cat|Cats]);
+        {Pid, Ref, terminate} ->
+            Pid ! {Ref, ok},
+            terminate(Cats);
+        Unknown ->
+            %% do some logging here too
+            io:format("Unknown message: ~p~n", [Unknown]),
+            loop(Cats)
+    end.
+
+%%% Private functions
+make_cat(Name, Col, Desc) ->
+    #cat{name=Name, color=Col, description=Desc}.
+
+terminate(Cats) ->
+    [io:format("~p was set free.~n",[C#cat.name]) || C <- Cats],
+    ok.