summaryrefslogtreecommitdiff
path: root/src/ui-calendar.c
blob: dcafc0f3f8623e44073d198fa16784b065349c5a (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
/*
 * Calcurse - text-based organizer
 *
 * Copyright (c) 2004-2016 calcurse Development Team <misc@calcurse.org>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the
 *        following disclaimer in the documentation and/or other
 *        materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * Send your feedback or comments to : misc@calcurse.org
 * Calcurse home page : http://calcurse.org
 *
 */

#include <unistd.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <time.h>
#include <math.h>

#include "calcurse.h"

#ifndef M_PI
#define	M_PI	  3.14159265358979323846
#endif

#define	EPOCH	  90
#define	EPSILONg  279.403303	/* solar ecliptic long at EPOCH */
#define	RHOg	  282.768422	/* solar ecliptic long of perigee at EPOCH */
#define	ECCEN	  0.016713	/* solar orbit eccentricity */
#define	lzero	  318.351648	/* lunar mean long at EPOCH */
#define	Pzero	  36.340410	/* lunar mean long of perigee at EPOCH */
#define	Nzero	  318.510107	/* lunar mean long of node at EPOCH */

#define ISLEAP(y) ((((y) % 4) == 0 && ((y) % 100) != 0) || ((y) % 400) == 0)

enum pom {
	NO_POM,
	FIRST_QUARTER,
	FULL_MOON,
	LAST_QUARTER,
	NEW_MOON,
	MOON_PHASES
};

static struct date today, slctd_day;
static unsigned ui_calendar_view, week_begins_on_monday;
static pthread_mutex_t date_thread_mutex = PTHREAD_MUTEX_INITIALIZER;
static pthread_t ui_calendar_t_date;

static void draw_monthly_view(struct scrollwin *, struct date *, unsigned);
static void draw_weekly_view(struct scrollwin *, struct date *, unsigned);
static void (*draw_calendar[CAL_VIEWS]) (struct scrollwin *, struct date *,
					 unsigned) = {
draw_monthly_view, draw_weekly_view};

static int monthly_view_cache[MAXDAYSPERMONTH];
static int monthly_view_cache_valid = 0;
static int monthly_view_cache_month = 0;

/* Switch between calendar views (monthly view is selected by default). */
void ui_calendar_view_next(void)
{
	ui_calendar_view++;
	if (ui_calendar_view == CAL_VIEWS)
		ui_calendar_view = 0;

	/* The calendar panel needs to be erased when switching views. */
	monthly_view_cache_month = 0;
}

void ui_calendar_view_prev(void)
{
	if (ui_calendar_view == 0)
		ui_calendar_view = CAL_VIEWS;
	ui_calendar_view--;

	/* The calendar panel needs to be erased when switching views. */
	monthly_view_cache_month = 0;
}

void ui_calendar_set_view(int view)
{
	ui_calendar_view = (view < 0
			    || view >= CAL_VIEWS) ? CAL_MONTH_VIEW : view;
}

int ui_calendar_get_view(void)
{
	return (int)ui_calendar_view;
}

/* Thread needed to update current date in calendar. */
/* ARGSUSED0 */
static void *ui_calendar_date_thread(void *arg)
{
	time_t actual, tomorrow;

	for (;;) {
		tomorrow = (time_t) (get_today() + DAYINSEC);

		while ((actual = time(NULL)) < tomorrow)
			sleep(tomorrow - actual);

		ui_calendar_set_current_date();
		ui_calendar_update_panel();
	}

	return NULL;
}

/* Launch the calendar date thread. */
void ui_calendar_start_date_thread(void)
{
	pthread_create(&ui_calendar_t_date, NULL, ui_calendar_date_thread,
		       NULL);
}

/* Stop the calendar date thread. */
void ui_calendar_stop_date_thread(void)
{
	if (ui_calendar_t_date) {
		pthread_cancel(ui_calendar_t_date);
		pthread_join(ui_calendar_t_date, NULL);
	}
}

/* Set static variable today to current date */
void ui_calendar_set_current_date(void)
{
	time_t timer;
	struct tm tm;

	timer = time(NULL);
	localtime_r(&timer, &tm);

	pthread_mutex_lock(&date_thread_mutex);
	today.dd = tm.tm_mday;
	today.mm = tm.tm_mon + 1;
	today.yyyy = tm.tm_year + 1900;
	pthread_mutex_unlock(&date_thread_mutex);
}

/* Needed to display sunday or monday as the first day of week in calendar. */
void ui_calendar_set_first_day_of_week(enum wday first_day)
{
	switch (first_day) {
	case SUNDAY:
		week_begins_on_monday = 0;
		break;
	case MONDAY:
		week_begins_on_monday = 1;
		break;
	default:
		ERROR_MSG(_("ERROR setting first day of week"));
		week_begins_on_monday = 0;
		/* NOTREACHED */
	}
}

/* Swap first day of week in calendar. */
void ui_calendar_change_first_day_of_week(void)
{
	week_begins_on_monday = !week_begins_on_monday;
}

/* Return 1 if week begins on monday, 0 otherwise. */
unsigned ui_calendar_week_begins_on_monday(void)
{
	return week_begins_on_monday;
}

/* Fill in the given variable with the current date. */
void ui_calendar_store_current_date(struct date *date)
{
	pthread_mutex_lock(&date_thread_mutex);
	*date = today;
	pthread_mutex_unlock(&date_thread_mutex);
}

/* This is to start at the current date in calendar. */
void ui_calendar_init_slctd_day(void)
{
	ui_calendar_store_current_date(&slctd_day);
}

/* Return the selected day in calendar */
struct date *ui_calendar_get_slctd_day(void)
{
	return &slctd_day;
}

/* Returned value represents the selected day in calendar (in seconds) */
time_t ui_calendar_get_slctd_day_sec(void)
{
	return date2sec(slctd_day, 0, 0);
}

static int ui_calendar_get_wday(struct date *date)
{
	struct tm t;

	memset(&t, 0, sizeof(struct tm));
	t.tm_mday = date->dd;
	t.tm_mon = date->mm - 1;
	t.tm_year = date->yyyy - 1900;

	mktime(&t);

	return t.tm_wday;
}

static unsigned months_to_days(unsigned month)
{
	return (month * 3057 - 3007) / 100;
}

static long years_to_days(unsigned year)
{
	return year * 365L + year / 4 - year / 100 + year / 400;
}

static long ymd_to_scalar(unsigned year, unsigned month, unsigned day)
{
	long scalar;

	scalar = day + months_to_days(month);
	if (month > 2)
		scalar -= ISLEAP(year) ? 1 : 2;
	year--;
	scalar += years_to_days(year);

	return scalar;
}

void ui_calendar_monthly_view_cache_set_invalid(void)
{
	monthly_view_cache_valid = 0;
}

static int weeknum(const struct tm *t, int firstweekday)
{
	int wday, wnum;

	wday = t->tm_wday;
	if (firstweekday == MONDAY) {
		if (wday == SUNDAY)
			wday = 6;
		else
			wday--;
	}
	wnum = ((t->tm_yday + WEEKINDAYS - wday) / WEEKINDAYS);
	if (wnum < 0)
		wnum = 0;

	return wnum;
}

/*
 * Compute the week number according to ISO 8601.
 */
static int ISO8601weeknum(const struct tm *t)
{
	int wnum, jan1day;

	wnum = weeknum(t, MONDAY);

	jan1day = t->tm_wday - (t->tm_yday % WEEKINDAYS);
	if (jan1day < 0)
		jan1day += WEEKINDAYS;

	switch (jan1day) {
	case MONDAY:
		break;
	case TUESDAY:
	case WEDNESDAY:
	case THURSDAY:
		wnum++;
		break;
	case FRIDAY:
	case SATURDAY:
	case SUNDAY:
		if (wnum == 0) {
			/* Get week number of last week of last year. */
			struct tm dec31ly;	/* 12/31 last year */

			dec31ly = *t;
			dec31ly.tm_year--;
			dec31ly.tm_mon = 11;
			dec31ly.tm_mday = 31;
			dec31ly.tm_wday =
			    (jan1day == SUNDAY) ? 6 : jan1day - 1;
			dec31ly.tm_yday =
			    364 + ISLEAP(dec31ly.tm_year + 1900);
			wnum = ISO8601weeknum(&dec31ly);
		}
		break;
	}

	if (t->tm_mon == 11) {
		int wday, mday;

		wday = t->tm_wday;
		mday = t->tm_mday;
		if ((wday == MONDAY && (mday >= 29 && mday <= 31))
		    || (wday == TUESDAY && (mday == 30 || mday == 31))
		    || (wday == WEDNESDAY && mday == 31))
			wnum = 1;
	}

	return wnum;
}

static struct tm get_first_weekday(unsigned sunday_first)
{
	int c_wday, days_to_remove;
	struct tm t;

	c_wday = ui_calendar_get_wday(&slctd_day);
	if (sunday_first)
		days_to_remove = c_wday;
	else
		days_to_remove = c_wday == 0 ? WEEKINDAYS - 1 : c_wday - 1;

	t = date2tm(slctd_day, 0, 0);
	date_change(&t, 0, -days_to_remove);

	return t;
}

static void draw_week_number(struct scrollwin *sw, struct tm t)
{
	int weeknum = ISO8601weeknum(&t);

	WINS_CALENDAR_LOCK;
	werase(sw_cal.inner);
	custom_apply_attr(sw->inner, ATTR_HIGHEST);
	if (wins_slctd() == CAL)
		wattron(sw->win, COLOR_PAIR(COLR_CUSTOM));
	mvwprintw(sw->win, conf.compact_panels ? 0 : 2, sw->w - 9,
		  "(# %02d)", weeknum);
	if (wins_slctd() == CAL)
		wattroff(sw->win, COLOR_PAIR(COLR_CUSTOM));
	custom_remove_attr(sw->inner, ATTR_HIGHEST);
	WINS_CALENDAR_UNLOCK;
}

/* Draw the monthly view inside calendar panel. */
static void
draw_monthly_view(struct scrollwin *sw, struct date *current_day,
		  unsigned sunday_first)
{
	struct date check_day;
	int c_day, c_day_1, day_1_sav, numdays, j;
	unsigned yr, mo;
	int w, ofs_x, ofs_y;
	int item_this_day = 0;
	struct tm t = get_first_weekday(sunday_first);

	mo = slctd_day.mm;
	yr = slctd_day.yyyy;

	/* offset for centering calendar in window */
	w = wins_sbar_width() - 2;
	ofs_y = 0;
	ofs_x = (w - 27) / 2;

	/* checking the number of days in february */
	numdays = days[mo - 1];
	if (2 == mo && ISLEAP(yr))
		++numdays;

	/*
	 * the first calendar day will be monday or sunday, depending on
	 * 'week_begins_on_monday' value
	 */
	c_day_1 =
	    (int)((ymd_to_scalar(yr, mo, 1 + sunday_first) -
		   (long)1) % 7L);

	/* Print the week number. */
	draw_week_number(sw, t);

	/* Write the current month and year on top of the calendar */
	WINS_CALENDAR_LOCK;
	if (yr * YEARINMONTHS + mo != monthly_view_cache_month) {
		/* erase the window if a new month is selected */
		werase(sw_cal.inner);
	}
	custom_apply_attr(sw->inner, ATTR_HIGHEST);
	mvwprintw(sw->inner, ofs_y,
		  (w - (strlen(_(monthnames[mo - 1])) + 5)) / 2,
		  "%s %d", _(monthnames[mo - 1]), slctd_day.yyyy);
	custom_remove_attr(sw->inner, ATTR_HIGHEST);
	++ofs_y;

	/* print the days, with regards to the first day of the week */
	custom_apply_attr(sw->inner, ATTR_HIGHEST);
	for (j = 0; j < WEEKINDAYS; j++) {
		mvwaddstr(sw->inner, ofs_y, ofs_x + 4 * j,
			  _(daynames[1 + j - sunday_first]));
	}
	custom_remove_attr(sw->inner, ATTR_HIGHEST);
	WINS_CALENDAR_UNLOCK;

	day_1_sav = (c_day_1 + 1) * 3 + c_day_1 - 7;

	/* invalidate cache if a new month is selected */
	if (yr * YEARINMONTHS + mo != monthly_view_cache_month) {
		monthly_view_cache_month = yr * YEARINMONTHS + mo;
		monthly_view_cache_valid = 0;
	}

	for (c_day = 1; c_day <= numdays; ++c_day, ++c_day_1, c_day_1 %= 7) {
		unsigned attr;

		check_day.dd = c_day;
		check_day.mm = slctd_day.mm;
		check_day.yyyy = slctd_day.yyyy;

		/* check if the day contains an event or an appointment */
		if (monthly_view_cache_valid) {
			item_this_day = monthly_view_cache[c_day - 1];
		} else {
			item_this_day = monthly_view_cache[c_day - 1] =
			    day_check_if_item(check_day);
		}

		/* Go to next line, the week is over. */
		if (!c_day_1 && 1 != c_day) {
			ofs_y++;
			ofs_x = (w - 27) / 2 - day_1_sav - 4 * c_day;
		}

		if (c_day == current_day->dd
		    && current_day->mm == slctd_day.mm
		    && current_day->yyyy == slctd_day.yyyy
		    && current_day->dd != slctd_day.dd)
			attr = ATTR_LOWEST;
		else if (c_day == slctd_day.dd)
			attr = ATTR_HIGHEST;
		else if (item_this_day == 1)
			attr = ATTR_LOW;
		else if (item_this_day == 2)
			attr = ATTR_TRUE;
		else
			attr = 0;

		WINS_CALENDAR_LOCK;
		if (attr)
			custom_apply_attr(sw->inner, attr);
		mvwprintw(sw->inner, ofs_y + 1,
			  ofs_x + day_1_sav + 4 * c_day + 1, "%2d", c_day);
		if (attr)
			custom_remove_attr(sw->inner, attr);
		WINS_CALENDAR_UNLOCK;
	}

	monthly_view_cache_valid = 1;
}

/* Draw the weekly view inside calendar panel. */
static void
draw_weekly_view(struct scrollwin *sw, struct date *current_day,
		 unsigned sunday_first)
{
#define DAYSLICESNO  6
	const int WCALWIDTH = 28;
	struct tm t = get_first_weekday(sunday_first);
	int OFFY, OFFX, j;

	OFFY = 0;
	OFFX = (wins_sbar_width() - 2 - WCALWIDTH) / 2;

	/* Print the week number. */
	draw_week_number(sw, t);

	/* Now draw calendar view. */
	for (j = 0; j < WEEKINDAYS; j++) {
		struct date date;
		unsigned attr, item_this_day;
		int i, slices[DAYSLICESNO];

		/* print the day names, with regards to the first day of the week */
		custom_apply_attr(sw->inner, ATTR_HIGHEST);
		mvwaddstr(sw->inner, OFFY, OFFX + 4 * j,
			  _(daynames[1 + j - sunday_first]));
		custom_remove_attr(sw->inner, ATTR_HIGHEST);

		/* Check if the day to be printed has an item or not. */
		date.dd = t.tm_mday;
		date.mm = t.tm_mon + 1;
		date.yyyy = t.tm_year + 1900;
		item_this_day = day_check_if_item(date);

		/* Print the day numbers with appropriate decoration. */
		if (t.tm_mday == current_day->dd
		    && current_day->mm == slctd_day.mm
		    && current_day->yyyy == slctd_day.yyyy
		    && current_day->dd != slctd_day.dd)
			attr = ATTR_LOWEST;
		else if (t.tm_mday == slctd_day.dd)
			attr = ATTR_HIGHEST;
		else if (item_this_day == 1)
			attr = ATTR_LOW;
		else if (item_this_day == 2)
			attr = ATTR_TRUE;
		else
			attr = 0;

		WINS_CALENDAR_LOCK;
		if (attr)
			custom_apply_attr(sw->inner, attr);
		mvwprintw(sw->inner, OFFY + 1, OFFX + 1 + 4 * j, "%02d",
			  t.tm_mday);
		if (attr)
			custom_remove_attr(sw->inner, attr);
		WINS_CALENDAR_UNLOCK;

		/* Draw slices indicating appointment times. */
		memset(slices, 0, DAYSLICESNO * sizeof *slices);
		if (day_chk_busy_slices(date, DAYSLICESNO, slices)) {
			for (i = 0; i < DAYSLICESNO; i++) {
				if (j != WEEKINDAYS - 1
				    && i != DAYSLICESNO - 1) {
					WINS_CALENDAR_LOCK;
					mvwhline(sw->inner, OFFY + 2 + i,
						 OFFX + 3 + 4 * j, ACS_S9,
						 2);
					WINS_CALENDAR_UNLOCK;
				}
				if (slices[i]) {
					int highlight;

					highlight =
					    (t.tm_mday ==
					     slctd_day.dd) ? 1 : 0;
					WINS_CALENDAR_LOCK;
					if (highlight)
						custom_apply_attr(sw->inner,
								  attr);
					wattron(sw->inner, A_REVERSE);
					mvwaddstr(sw->inner, OFFY + 2 + i,
						  OFFX + 1 + 4 * j, " ");
					mvwaddstr(sw->inner, OFFY + 2 + i,
						  OFFX + 2 + 4 * j, " ");
					wattroff(sw->inner, A_REVERSE);
					if (highlight)
						custom_remove_attr(sw->inner,
								   attr);
					WINS_CALENDAR_UNLOCK;
				}
			}
		}

		/* get next day */
		date_change(&t, 0, 1);
	}

	/* Draw marks to indicate midday on the sides of the calendar. */
	WINS_CALENDAR_LOCK;
	custom_apply_attr(sw->inner, ATTR_HIGHEST);
	mvwhline(sw->inner, OFFY + 1 + DAYSLICESNO / 2, OFFX, ACS_S9, 1);
	mvwhline(sw->inner, OFFY + 1 + DAYSLICESNO / 2,
		 OFFX + WCALWIDTH - 1, ACS_S9, 1);
	custom_remove_attr(sw->inner, ATTR_HIGHEST);
	WINS_CALENDAR_UNLOCK;

#undef DAYSLICESNO
}

/* Function used to display the calendar panel. */
void ui_calendar_update_panel(void)
{
	struct date current_day;
	unsigned sunday_first;

	ui_calendar_store_current_date(&current_day);
	sunday_first = !ui_calendar_week_begins_on_monday();
	draw_calendar[ui_calendar_view] (&sw_cal, &current_day, sunday_first);
	wins_scrollwin_display(&sw_cal);
}

/* Set the selected day in calendar to current day. */
void ui_calendar_goto_today(void)
{
	struct date today;

	ui_calendar_store_current_date(&today);
	slctd_day.dd = today.dd;
	slctd_day.mm = today.mm;
	slctd_day.yyyy = today.yyyy;
}

/*
 * Ask for a date to jump to, then check the correctness of that date
 * and jump to it.
 * If the entered date is empty, automatically jump to the current date.
 * slctd_day is updated with the newly selected date.
 */
void ui_calendar_change_day(int datefmt)
{
#define LDAY 11
	char selected_day[LDAY] = "";
	char *outstr;
	int dday, dmonth, dyear;
	int wrong_day = 1;
	const char *mesg_line1 = _("The day you entered is not valid");
	const char *mesg_line2 = _("Press [ENTER] to continue");
	const char *request_date =
	    _("Enter the day to go to [ENTER for today] : %s");

	while (wrong_day) {
		asprintf(&outstr, request_date, DATEFMT_DESC(datefmt));
		status_mesg(outstr, "");
		mem_free(outstr);
		if (getstring(win[STA].p, selected_day, LDAY, 0, 1) ==
		    GETSTRING_ESC) {
			return;
		} else {
			if (strlen(selected_day) == 0) {
				wrong_day = 0;
				ui_calendar_goto_today();
			} else
			    if (parse_date
				(selected_day, datefmt, &dyear, &dmonth,
				 &dday, ui_calendar_get_slctd_day())) {
				wrong_day = 0;
				/* go to chosen day */
				slctd_day.dd = dday;
				slctd_day.mm = dmonth;
				slctd_day.yyyy = dyear;
			}
			if (wrong_day) {
				status_mesg(mesg_line1, mesg_line2);
				wgetch(win[KEY].p);
			}
		}
	}

	return;
}

void ui_calendar_move(enum move move, int count)
{
	int ret, days_to_remove, days_to_add;
	struct tm t;

	memset(&t, 0, sizeof(struct tm));
	t.tm_mday = slctd_day.dd;
	t.tm_mon = slctd_day.mm - 1;
	t.tm_year = slctd_day.yyyy - 1900;

	switch (move) {
	case DAY_PREV:
		ret = date_change(&t, 0, -count);
		break;
	case DAY_NEXT:
		ret = date_change(&t, 0, count);
		break;
	case WEEK_PREV:
		ret = date_change(&t, 0, -count * WEEKINDAYS);
		break;
	case WEEK_NEXT:
		ret = date_change(&t, 0, count * WEEKINDAYS);
		break;
	case MONTH_PREV:
		ret = date_change(&t, -count, 0);
		break;
	case MONTH_NEXT:
		ret = date_change(&t, count, 0);
		break;
	case YEAR_PREV:
		ret = date_change(&t, -count * YEARINMONTHS, 0);
		break;
	case YEAR_NEXT:
		ret = date_change(&t, count * YEARINMONTHS, 0);
		break;
	case WEEK_START:
		/* Normalize struct tm to get week day number. */
		mktime(&t);
		if (ui_calendar_week_begins_on_monday())
			days_to_remove =
			    ((t.tm_wday ==
			      0) ? WEEKINDAYS - 1 : t.tm_wday - 1);
		else
			days_to_remove =
			    ((t.tm_wday == 0) ? 0 : t.tm_wday);
		days_to_remove += (count - 1) * WEEKINDAYS;
		ret = date_change(&t, 0, -days_to_remove);
		break;
	case WEEK_END:
		mktime(&t);
		if (ui_calendar_week_begins_on_monday())
			days_to_add =
			    ((t.tm_wday ==
			      0) ? 0 : WEEKINDAYS - t.tm_wday);
		else
			days_to_add = ((t.tm_wday == 0) ?
				       WEEKINDAYS - 1 : WEEKINDAYS - 1 -
				       t.tm_wday);
		days_to_add += (count - 1) * WEEKINDAYS;
		ret = date_change(&t, 0, days_to_add);
		break;
	default:
		ret = 1;
		/* NOTREACHED */
	}

	if (ret == 0) {
		if (t.tm_year < 2) {
			t.tm_mday = 1;
			t.tm_mon = 0;
			t.tm_year = 2;
		}

		slctd_day.dd = t.tm_mday;
		slctd_day.mm = t.tm_mon + 1;
		slctd_day.yyyy = t.tm_year + 1900;
	}
}

/* Returns the beginning of current year as a long. */
long ui_calendar_start_of_year(void)
{
	time_t timer;
	struct tm tm;

	timer = time(NULL);
	localtime_r(&timer, &tm);
	tm.tm_mon = 0;
	tm.tm_mday = 1;
	tm.tm_hour = 0;
	tm.tm_min = 0;
	tm.tm_sec = 0;
	timer = mktime(&tm);

	return (long)timer;
}

long ui_calendar_end_of_year(void)
{
	time_t timer;
	struct tm tm;

	timer = time(NULL);
	localtime_r(&timer, &tm);
	tm.tm_mon = 0;
	tm.tm_mday = 1;
	tm.tm_hour = 0;
	tm.tm_min = 0;
	tm.tm_sec = 0;
	tm.tm_year++;
	timer = mktime(&tm);

	return (long)(timer - 1);
}

/*
 * The pom, potm, dotr, adj360 are used to compute the current
 * phase of the moon.
 * The code is based on the OpenBSD version of pom(6).
 * Below is reported the copyright notice.
 */
/*
 * Copyright (c) 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software posted to USENET.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

/*
 * dtor --
 *	convert degrees to radians
 */
static double dtor(double deg)
{
	return deg * M_PI / 180;
}

/*
 * adj360 --
 *	adjust value so 0 <= deg <= 360
 */
static void adj360(double *deg)
{
	for (;;)
		if (*deg < 0.0)
			*deg += 360.0;
		else if (*deg > 360.0)
			*deg -= 360.0;
		else
			break;
}

/*
 * potm --
 *	return phase of the moon
 */
static double potm(double days)
{
	double N, Msol, Ec, LambdaSol, l, Mm, Ev, Ac, A3, Mmprime;
	double A4, lprime, V, ldprime, D, Nm;

	N = 360.0 * days / 365.242191;	/* sec 46 #3 */
	adj360(&N);
	Msol = N + EPSILONg - RHOg;	/* sec 46 #4 */
	adj360(&Msol);
	Ec = 360 / M_PI * ECCEN * sin(dtor(Msol));	/* sec 46 #5 */
	LambdaSol = N + Ec + EPSILONg;	/* sec 46 #6 */
	adj360(&LambdaSol);
	l = 13.1763966 * days + lzero;	/* sec 65 #4 */
	adj360(&l);
	Mm = l - (0.1114041 * days) - Pzero;	/* sec 65 #5 */
	adj360(&Mm);
	Nm = Nzero - (0.0529539 * days);	/* sec 65 #6 */
	adj360(&Nm);
	Ev = 1.2739 * sin(dtor(2 * (l - LambdaSol) - Mm));	/* sec 65 #7 */
	Ac = 0.1858 * sin(dtor(Msol));	/* sec 65 #8 */
	A3 = 0.37 * sin(dtor(Msol));
	Mmprime = Mm + Ev - Ac - A3;	/* sec 65 #9 */
	Ec = 6.2886 * sin(dtor(Mmprime));	/* sec 65 #10 */
	A4 = 0.214 * sin(dtor(2 * Mmprime));	/* sec 65 #11 */
	lprime = l + Ev + Ec - Ac + A4;	/* sec 65 #12 */
	V = 0.6583 * sin(dtor(2 * (lprime - LambdaSol)));	/* sec 65 #13 */
	ldprime = lprime + V;	/* sec 65 #14 */
	D = ldprime - LambdaSol;	/* sec 67 #2 */
	return 50.0 * (1 - cos(dtor(D)));	/* sec 67 #3 */
}

/*
 * Phase of the Moon.  Calculates the current phase of the moon.
 * Based on routines from `Practical Astronomy with Your Calculator',
 * by Duffett-Smith.  Comments give the section from the book that
 * particular piece of code was adapted from.
 *
 * -- Keith E. Brandt  VIII 1984
 *
 * Updated to the Third Edition of Duffett-Smith's book, IX 1998
 *
 */
static double pom(time_t tmpt)
{
	struct tm *GMT;
	double days;
	int cnt;

	GMT = gmtime(&tmpt);
	days = (GMT->tm_yday + 1) + ((GMT->tm_hour + (GMT->tm_min / 60.0) +
				      (GMT->tm_sec / 3600.0)) / 24.0);
	for (cnt = EPOCH; cnt < GMT->tm_year; ++cnt)
		days += ISLEAP(cnt + TM_YEAR_BASE) ? 366 : 365;
	/* Selected time could be before EPOCH */
	for (cnt = GMT->tm_year; cnt < EPOCH; ++cnt)
		days -= ISLEAP(cnt + TM_YEAR_BASE) ? 366 : 365;

	return potm(days);
}

/*
 * Return a pictogram representing the current phase of the moon.
 * Careful: date is the selected day in calendar at 00:00, so it represents
 * the phase of the moon for previous day.
 */
const char *ui_calendar_get_pom(time_t date)
{
	const char *pom_pict[MOON_PHASES] =
	    { "   ", "|) ", "(|)", "(| ", " | " };
	enum pom phase = NO_POM;
	double pom_today, relative_pom, pom_yesterday, pom_tomorrow;
	const double half = 50.0;

	pom_yesterday = pom(date);
	pom_today = pom(date + DAYINSEC);
	relative_pom = abs(pom_today - half);
	pom_tomorrow = pom(date + 2 * DAYINSEC);
	if (pom_today > pom_yesterday && pom_today > pom_tomorrow)
		phase = FULL_MOON;
	else if (pom_today < pom_yesterday && pom_today < pom_tomorrow)
		phase = NEW_MOON;
	else if (relative_pom < abs(pom_yesterday - half)
		 && relative_pom < abs(pom_tomorrow - half))
		phase =
		    (pom_tomorrow >
		     pom_today) ? FIRST_QUARTER : LAST_QUARTER;

	return pom_pict[phase];
}