%%
%% %CopyrightBegin%
%%
%% Copyright Ericsson AB 1997-2010. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
%% compliance with the License. You should have received a copy of the
%% Erlang Public License along with this software. If not, it can be
%% retrieved online at http://www.erlang.org/.
%%
%% Software distributed under the License is distributed on an "AS IS"
%% basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
%% the License for the specific language governing rights and limitations
%% under the License.
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%% %CopyrightEnd%
%%
-module(calendar_SUITE).

-include_lib("test_server/include/test_server.hrl").

-export([all/0, suite/0,groups/0,init_per_suite/1, end_per_suite/1, 
	 init_per_group/2,end_per_group/2, 
	 gregorian_days/1,
	 gregorian_seconds/1,
	 day_of_the_week/1,
	 day_of_the_week_calibrate/1,
	 leap_years/1,
	 last_day_of_the_month/1,
	 local_time_to_universal_time_dst/1,
	 iso_week_number/1]).

-define(START_YEAR, 1947).			
-define(END_YEAR, 2012).

suite() -> [{ct_hooks,[ts_install_cth]}].

all() -> 
    [gregorian_days, gregorian_seconds, day_of_the_week,
     day_of_the_week_calibrate, leap_years,
     last_day_of_the_month, local_time_to_universal_time_dst, iso_week_number].

groups() -> 
    [].

init_per_suite(Config) ->
    Config.

end_per_suite(_Config) ->
    ok.

init_per_group(_GroupName, Config) ->
    Config.

end_per_group(_GroupName, Config) ->
    Config.

gregorian_days(doc) ->
    "Tests that date_to_gregorian_days and gregorian_days_to_date "
    "are each others inverses from ?START_YEAR-01-01 up to ?END_YEAR-01-01. "
    "At the same time valid_date is tested.";
gregorian_days(suite) ->
    [];
gregorian_days(Config) when is_list(Config) ->
    ?line Days = calendar:date_to_gregorian_days({?START_YEAR, 1, 1}),
    ?line MaxDays = calendar:date_to_gregorian_days({?END_YEAR, 1, 1}),
    ?line check_gregorian_days(Days, MaxDays).

gregorian_seconds(doc) ->
    "Tests that datetime_to_gregorian_seconds and "
    "gregorian_seconds_to_date are each others inverses for a sampled "
    "number of seconds from ?START_YEAR-01-01 up to ?END_YEAR-01-01: We check "
    "every 2 days + 1 second.";
gregorian_seconds(suite) ->
    [];
gregorian_seconds(Config) when is_list(Config) ->
    ?line Secs = calendar:datetime_to_gregorian_seconds({{?START_YEAR, 1, 1},
							 {0, 0, 0}}),
    ?line MaxSecs = calendar:datetime_to_gregorian_seconds({{?END_YEAR, 1, 1},
							    {0, 0, 0}}),
    ?line check_gregorian_seconds(Secs, MaxSecs).

day_of_the_week(doc) ->
    "Tests that day_of_the_week reports correctly the day of the week from "
    "year ?START_YEAR up to ?END_YEAR.";
day_of_the_week(suite) ->
    [];
day_of_the_week(Config) when is_list(Config) ->
    ?line Days = calendar:date_to_gregorian_days({?START_YEAR, 1, 1}),
    ?line MaxDays = calendar:date_to_gregorian_days({?END_YEAR, 1, 1}),
    ?line DayNumber = calendar:day_of_the_week({?START_YEAR, 1, 1}),
    ?line check_day_of_the_week(Days, MaxDays, DayNumber).

day_of_the_week_calibrate(doc) ->
    "Tests that day_of_the_week for 1997-11-11 is Tuesday (2)";
day_of_the_week_calibrate(suite) ->
    [];
day_of_the_week_calibrate(Config) when is_list(Config) ->
    ?line 2 = calendar:day_of_the_week({1997, 11, 11}).

leap_years(doc) ->
    "Tests that is_leap_year reports correctly the leap years from "
    "year ?START_YEAR up to ?END_YEAR.";
leap_years(suite) ->
    [];
leap_years(Config) when is_list(Config) ->
    ?line check_leap_years(?START_YEAR, ?END_YEAR).

last_day_of_the_month(doc) ->
    "Tests that last_day_of_the_month reports correctly from "
    "year ?START_YEAR up to ?END_YEAR.";
last_day_of_the_month(suite) ->
    [];
last_day_of_the_month(Config) when is_list(Config) ->
    ?line check_last_day_of_the_month({?START_YEAR, 1}, {?END_YEAR, 1}).

local_time_to_universal_time_dst(doc) ->
    "Tests local_time_to_universal_time_dst for MET";
local_time_to_universal_time_dst(suite) ->
    [];
local_time_to_universal_time_dst(Config) when is_list(Config) ->
    case os:type() of
	{unix,_} ->
	    case os:cmd("date '+%Z'") of
		"SAST"++_ ->
		    {comment, "Spoky time zone with zero-set DST, skipped"};
		_ ->
		    local_time_to_universal_time_dst_x(Config)
	    end;
	_ ->
	    local_time_to_universal_time_dst_x(Config)
    end.
local_time_to_universal_time_dst_x(Config) when is_list(Config) ->
    %% Assumes MET (UTC+1 / UTC+2(dst)
    ?line LtW   = {{2003,01,15},{14,00,00}}, % Winter
    ?line UtW   = {{2003,01,15},{13,00,00}}, % 
    ?line UtWd  = {{2003,01,15},{12,00,00}}, % dst
    ?line LtS   = {{2003,07,15},{14,00,00}}, % Summer
    ?line UtS   = {{2003,07,15},{13,00,00}}, % 
    ?line UtSd  = {{2003,07,15},{12,00,00}}, % dst
    ?line LtWS  = {{2003,03,30},{02,30,00}}, % Winter->Summer
    ?line UtWS  = {{2003,03,30},{01,30,00}}, % 
    ?line UtWSd = {{2003,03,30},{00,30,00}}, % dst
    ?line LtSW  = {{2003,10,26},{02,30,00}}, % Summer->Winter
    ?line UtSW  = {{2003,10,26},{01,30,00}}, % 
    ?line UtSWd = {{2003,10,26},{00,30,00}}, % dst
    %%
    ?line UtW   = calendar:local_time_to_universal_time(LtW, false),
    ?line UtWd  = calendar:local_time_to_universal_time(LtW, true),
    ?line UtW   = calendar:local_time_to_universal_time(LtW, undefined),
    %%
    ?line UtS   = calendar:local_time_to_universal_time(LtS, false),
    ?line UtSd  = calendar:local_time_to_universal_time(LtS, true),
    ?line UtSd  = calendar:local_time_to_universal_time(LtS, undefined),
    %%
    case calendar:local_time_to_universal_time(LtWS, false) of
	UtWS ->
	    ?line UtWSd = calendar:local_time_to_universal_time(LtWS, true),
	    ?line []    = calendar:local_time_to_universal_time_dst(LtWS),
	    %%
	    ?line UtSW  = calendar:local_time_to_universal_time(LtSW, false),
	    ?line UtSWd = calendar:local_time_to_universal_time(LtSW, true),
	    ?line [UtSWd, UtSW] = calendar:local_time_to_universal_time_dst(LtSW),
	    ok;
	{{1969,12,31},{23,59,59}} ->
	    %% It seems that Apple has no intention of fixing this bug in
	    %% Mac OS 10.3.9, and we have no intention of implementing a
	    %% workaround. 
	    {comment,"Bug in mktime() in this OS"}
    end.

iso_week_number(doc) ->
	"Test the iso week number calculation for all three possibilities."
	" When the date falls on the last week of the previous year,"
	" when the date falls on a week within the given year and finally,"
	" when the date falls on the first week of the next year.";
iso_week_number(suite) ->
	[];
iso_week_number(Config) when is_list(Config) ->
	?line check_iso_week_number().

%%
%% LOCAL FUNCTIONS
%%

%% check_gregorian_days
%% 
check_gregorian_days(Days, MaxDays) when Days < MaxDays ->
    ?line Date = calendar:gregorian_days_to_date(Days), 
    ?line true = calendar:valid_date(Date),
    ?line Days = calendar:date_to_gregorian_days(Date),
    ?line check_gregorian_days(Days + 1, MaxDays);
check_gregorian_days(_Days, _MaxDays) ->
    ok.

%% check_gregorian_seconds
%% 
%% We increment with something prime (172801 = 2 days + 1 second).
%%
check_gregorian_seconds(Secs, MaxSecs) when Secs < MaxSecs ->
    ?line DateTime = calendar:gregorian_seconds_to_datetime(Secs), 
    ?line Secs = calendar:datetime_to_gregorian_seconds(DateTime),
    ?line check_gregorian_seconds(Secs + 172801, MaxSecs);
check_gregorian_seconds(_Secs, _MaxSecs) ->
    ok.


%% check_day_of_the_week
%%
check_day_of_the_week(Days, MaxDays, DayNumber) when Days < MaxDays ->
    ?line Date = calendar:gregorian_days_to_date(Days),
    ?line DayNumber = calendar:day_of_the_week(Date),
    ?line check_day_of_the_week(Days + 1, MaxDays, 
				((DayNumber rem 7) + 1));
check_day_of_the_week(_Days, _MaxDays, _DayNumber) ->
    ok.

%% check_leap_years
%%
%% SYr must be larger than 1800, and EYr must be less than ?END_YEAR.
%%
check_leap_years(SYr, EYr) when SYr < EYr ->
    ?line Rem = SYr rem 4,
    case Rem of
	0 ->
	    case SYr of
		1900 ->
		    ?line false = calendar:is_leap_year(SYr);
		2000 ->
		    ?line true = calendar:is_leap_year(SYr);
		_  ->
		    ?line true = calendar:is_leap_year(SYr)
	    end;
	_ ->
	    ?line false = calendar:is_leap_year(SYr)
    end,
    check_leap_years(SYr + 1, EYr);
check_leap_years(_SYr, _EYr) ->
    ok.

check_last_day_of_the_month({SYr, SMon}, {EYr, EMon}) when SYr < EYr ->
    ?line LastDay = calendar:last_day_of_the_month(SYr, SMon),
    ?line LastDay = case SMon of
			 1 -> 31;
			 2 ->
			     case calendar:is_leap_year(SYr) of
				 true -> 29;
				 false  -> 28
			     end;
			 3 -> 31;
			 4 -> 30;
			 5 -> 31;
			 6 -> 30;
			 7 -> 31;
			 8 -> 31;
			 9 -> 30;
			 10 -> 31;
			 11 -> 30;
			 12 -> 31
		     end,
    ?line NYr = case SMon of
		    12 -> SYr + 1;
		    _ -> SYr
		end,
    ?line check_last_day_of_the_month({NYr, (SMon rem 12) + 1}, 
				      {EYr, EMon});
check_last_day_of_the_month(_, _) ->
    ok.

%% check_iso_week_number
%%
check_iso_week_number() ->
    ?line {2004, 53} = calendar:iso_week_number({2005, 1, 1}),
    ?line {2007, 1} = calendar:iso_week_number({2007, 1, 1}),
    ?line {2009, 1} = calendar:iso_week_number({2008, 12, 29}).