Add timezone server basics with some tests

rebar.config

@@ -9,5 +9,5 @@
 
 {deps, [
     {erlware_commons, ".*", {git, "git://github.com/erlware/erlware_commons.git", "HEAD"}},
-    {erlang_localtime, ".*", {git, "git://github.com/dmitryme/erlang_localtime.git", "HEAD"}}
+    {erlang_localtime, ".*", {git, "git://github.com/choptastic/erlang_localtime.git", "HEAD"}}
 ]}.

src/qdate.app.src

@@ -7,6 +7,6 @@
                   kernel,
                   stdlib
                  ]},
-  {mod, { qdate, []}},
+  {mod, { qdate_app, []}},
   {env, []}
  ]}.

src/qdate.erl

@@ -21,12 +21,14 @@
 %% 	register_format/1
 %% ]).
 %% 
-%% -export([
-%% 	set_timezone/1,
-%% 	set_timezone/2,
-%% 	get_timezone/0,
-%% 	get_timezone/1
-%% ]).
+-export([
+	set_timezone/1,
+	set_timezone/2,
+	get_timezone/0,
+	get_timezone/1,
+	clear_timezone/0,
+	clear_timezone/1
+]).
 
 
 %% Exported for API compatibility with ec_date
@@ -52,11 +54,14 @@
 						TZ -> TZ 
 					end).
 
+-define(DETERMINE_TZ, determine_timezone()).
+
+
 to_string(Format) ->
 	to_string(Format, now()).
 
 to_string(Format, Date) ->
-	to_string(Format, ?DEFAULT_TZ, Date).
+	to_string(Format, ?DETERMINE_TZ, Date).
 
 to_string(Format, ToTZ, Date) ->
 	ec_date:format(Format,to_date(Date,ToTZ)).
@@ -85,28 +90,51 @@ raw_to_date(Date = {{_,_,_},{_,_,_}}) ->
 	Date.
 
 to_date(RawDate) ->
-	to_date(RawDate, ?DEFAULT_TZ).
+	to_date(RawDate, ?DETERMINE_TZ).
 
+to_date(RawDate, ToTZKey) when is_atom(ToTZKey) orelse is_tuple(ToTZKey) ->
+	case get_timezone(ToTZKey) of
+		undefined -> throw({timezone_key_not_found,ToTZKey});
+		ToTZ -> to_date(RawDate, ToTZ)
+	end;
 to_date(RawDate, ToTZ)  ->
 	{RawDate2,FromTZ} = extract_timezone(RawDate),
 	Date = raw_to_date(RawDate2),
 	localtime:local_to_local(Date,FromTZ,ToTZ).
 
+set_timezone(TZ) ->
+	qdate_srv:set_timezone(TZ).
+
+set_timezone(Key,TZ) ->
+	qdate_srv:set_timezone(Key, TZ).
+
+get_timezone() ->
+	qdate_srv:get_timezone().
+
+get_timezone(Key) ->
+	qdate_srv:get_timezone(Key).
+
+clear_timezone() ->
+	qdate_srv:clear_timezone().
+
+clear_timezone(Key) ->
+	qdate_srv:clear_timezone(Key).
+
 extract_timezone(Unixtime) when is_integer(Unixtime) ->
-	{Unixtime, ?DEFAULT_TZ};
+	{Unixtime, ?DETERMINE_TZ};
 extract_timezone(DateString) when is_list(DateString) ->
 	AllTimezones = localtime:list_timezones(),
 	RevDate = lists:reverse(DateString),
 	extract_timezone_helper(RevDate, AllTimezones);
 extract_timezone(Date={{_,_,_},{_,_,_}}) ->
-	{Date, ?DEFAULT_TZ};
+	{Date, ?DETERMINE_TZ};
 extract_timezone(Now={_,_,_}) ->
-	{Now, ?DEFAULT_TZ};
+	{Now, ?DETERMINE_TZ};
 extract_timezone({MiscDate,TZ}) ->
 	{MiscDate,TZ}.
 	
 extract_timezone_helper(RevDate, []) ->
-	{lists:reverse(RevDate), ?DEFAULT_TZ};
+	{lists:reverse(RevDate), ?DETERMINE_TZ};
 extract_timezone_helper(RevDate, [TZ | TZs]) ->
 	RevTZ = lists:reverse(TZ),
 	case lists:split(length(TZ),RevDate) of
@@ -116,6 +144,12 @@ extract_timezone_helper(RevDate, [TZ | TZs]) ->
 			extract_timezone_helper(RevDate, TZs)
 	end.
 
+determine_timezone() ->
+	case qdate_srv:get_timezone() of
+		undefined -> ?DEFAULT_TZ;
+		TZ -> TZ
+	end.
+
 to_unixtime(Unixtime) when is_integer(Unixtime) ->
 	Unixtime;
 to_unixtime({MegaSecs,Secs,_}) ->
@@ -156,7 +190,36 @@ floor(N) when N < 0 ->
 %% TESTS
 -include_lib("eunit/include/eunit.hrl").
 
-all_test_() ->
+%% emulates as if a forum-type website has a Site tz, and a user-specified tz
+-define(SITE_TZ,"PST").
+-define(USER_TZ,"CST").
+-define(SELF_TZ,"EST"). %% Self will be the pid of the current running process
+-define(SITE_KEY,test_site_key).
+-define(USER_KEY,test_user_key).
+
+
+
+tz_test_() ->
+	{
+		setup,
+		fun start_test/0,
+		fun stop_test/1,
+		fun(SetupData) ->
+			{spawn,[
+				simple_test(),
+				tz_tests(SetupData)
+			]}
+		end
+	}.
+
+tz_tests(_) ->
+	[
+		?_assertEqual(?SELF_TZ,begin set_timezone(?SELF_TZ),get_timezone() end),
+		?_assertEqual(?USER_TZ,get_timezone(?USER_KEY)),
+		?_assertEqual(?SITE_TZ,get_timezone(?SITE_KEY))
+	].
+
+simple_test() ->
 	[
 		?_assertEqual(0,to_unixtime({0,0,0})),
 		?_assertEqual({0,0,0},to_now(0)),
@@ -171,3 +234,18 @@ all_test_() ->
 		?_assertEqual({{2013,1,1},{0,15,15}},to_date("December 31, 2012 6:15:15pm CST","GMT"))
 	].
 
+%%tz_char_tests(_) ->
+%%	qdate:set_timezone(?SELF_TZ),
+
+
+
+	
+		
+		
+start_test() ->
+	application:start(qdate),
+	qdate:set_timezone(?SITE_KEY,?SITE_TZ),
+	qdate:set_timezone(?USER_KEY,?USER_TZ).
+
+stop_test(_) ->
+	ok.

src/qdate_app.erl

@@ -0,0 +1,16 @@
+-module(qdate_app).
+
+-behaviour(application).
+
+%% Application callbacks
+-export([start/2, stop/1]).
+
+%% ===================================================================
+%% Application callbacks
+%% ===================================================================
+
+start(_StartType, _StartArgs) ->
+    qdate_sup:start_link().
+
+stop(_State) ->
+    ok.

src/qdate_srv.erl

@@ -0,0 +1,114 @@
+-module(qdate_srv).
+-behaviour(gen_server).
+
+-define(SRV, ?MODULE).
+
+-export([
+	start_link/0,
+	init/1,
+	handle_call/3,
+	handle_cast/2,
+	handle_info/2,
+	code_change/3,
+	terminate/2
+]).
+
+-export([
+	set_timezone/1,
+	set_timezone/2,
+
+	get_timezone/0,
+	get_timezone/1,
+
+	clear_timezone/0,
+	clear_timezone/1
+
+%%	register_parser/1,
+%%	register_parser/2,
+%%	
+%%	deregister_parsers/0,
+%%	deregister_parsers/1,
+%%
+%%	register_format/1,
+%%	register_format/2,
+%%
+%%	deregister_format/0,
+%%	deregister_format/1
+]).
+
+%% PUBLIC API FUNCTIONS
+
+start_link() ->
+	gen_server:start_link({local, ?SRV}, ?MODULE, [], []).
+
+set_timezone(TZ) ->
+	set_timezone(self(),TZ).
+
+set_timezone(Key,TZ) ->
+	gen_server:call(?SRV,{set_timezone,Key,TZ}).
+
+get_timezone() ->
+	get_timezone(self()).
+
+get_timezone(Key) ->
+	gen_server:call(?SRV,{get_timezone,Key}).
+
+clear_timezone() ->
+	clear_timezone(self()).
+
+clear_timezone(Key) ->
+	gen_server:call(?SRV, {clear_timezone, Key}).
+
+%% SERVER FUNCTIONS
+
+-record(state, {tz, parsers, formats}).
+
+init(_) ->
+	State = #state{tz=dict:new(),parsers=dict:new(),formats=dict:new()},
+	{ok, State}.
+
+handle_cast(_,State) ->
+	{noreply, State}.
+
+handle_info({'DOWN', MonitorRef, process, Pid, _Reason}, State) ->
+	erlang:demonitor(MonitorRef),
+	NewTZ = dict:erase(Pid, State#state.tz),
+	NewParsers = dict:erase(Pid, State#state.parsers),
+	NewFormats = dict:erase(Pid, State#state.formats),
+	NewState = State#state{tz=NewTZ, parsers=NewParsers, formats=NewFormats},	
+	{noreply, NewState };
+handle_info(_, State) ->
+	{noreply, State}.
+
+handle_call({set_timezone,Key,TZ}, _From, State) ->
+	monitor_if_pid(Key),
+	NewTZ = dict:store(Key, TZ, State#state.tz),
+	NewState = State#state{tz=NewTZ},
+	{reply, ok, NewState};
+handle_call({clear_timezone,Key},_From, State) ->
+	NewTZ = dict:erase(Key, State#state.tz),
+	NewState = State#state{tz=NewTZ},
+	{reply, ok, NewState};
+handle_call({get_timezone,Key},_From, State) ->
+	Reply = case dict:find(Key, State#state.tz) of
+		error -> undefined;
+		{ok, Value} -> Value
+	end,
+	{reply, Reply, State}.
+%% handle_call({register_parser,Key,Parser}) ->
+%% handle_call({deregister_parsers,Key}) ->
+%% handle_call({register_format,Key,Format}) ->
+%% handle_call({deregister_formats,Key}) ->
+
+terminate(_Reason, _State) ->
+	ok.
+
+code_change(_OldVersion, State, _Extra) ->
+	{ok, State}.
+
+%% PRIVATE TOOLS
+
+monitor_if_pid(Key) when is_pid(Key) ->
+	erlang:monitor(process,Key);
+monitor_if_pid(_) ->
+	do_nothing.

src/qdate_sup.erl

@@ -0,0 +1,29 @@
+
+-module(qdate_sup).
+
+-behaviour(supervisor).
+
+%% API
+-export([start_link/0]).
+
+%% Supervisor callbacks
+-export([init/1]).
+
+%% Helper macro for declaring children of supervisor
+-define(CHILD(I, Type), {I, {I, start_link, []}, permanent, 5000, Type, [I]}).
+
+%% ===================================================================
+%% API functions
+%% ===================================================================
+
+start_link() ->
+    supervisor:start_link({local, ?MODULE}, ?MODULE, []).
+
+%% ===================================================================
+%% Supervisor callbacks
+%% ===================================================================
+
+init([]) ->
+	Server = ?CHILD(qdate_srv, worker),
+    {ok, { {one_for_one, 5, 10}, [Server]} }.
+