1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3/*
4 * Copyright (C) 2003-2014, International Business Machines Corporation
5 * and others. All Rights Reserved.
6 ******************************************************************************
7 *
8 * File INDIANCAL.CPP
9 *****************************************************************************
10 */
11
12#include "indiancal.h"
13#include <stdlib.h>
14#if !UCONFIG_NO_FORMATTING
15
16#include "mutex.h"
17#include <float.h>
18#include "gregoimp.h" // Math
19#include "astro.h" // CalendarAstronomer
20#include "uhash.h"
21
22// Debugging
23#ifdef U_DEBUG_INDIANCAL
24#include <stdio.h>
25#include <stdarg.h>
26
27#endif
28
29U_NAMESPACE_BEGIN
30
31// Implementation of the IndianCalendar class
32
33//-------------------------------------------------------------------------
34// Constructors...
35//-------------------------------------------------------------------------
36
37
38Calendar* IndianCalendar::clone() const {
39  return new IndianCalendar(*this);
40}
41
42IndianCalendar::IndianCalendar(const Locale& aLocale, UErrorCode& success)
43  :   Calendar(TimeZone::createDefault(), aLocale, success)
44{
45  setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
46}
47
48IndianCalendar::IndianCalendar(const IndianCalendar& other) : Calendar(other) {
49}
50
51IndianCalendar::~IndianCalendar()
52{
53}
54const char *IndianCalendar::getType() const {
55   return "indian";
56}
57
58static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
59    // Minimum  Greatest     Least   Maximum
60    //           Minimum   Maximum
61    {        0,        0,        0,        0}, // ERA
62    { -5000000, -5000000,  5000000,  5000000}, // YEAR
63    {        0,        0,       11,       11}, // MONTH
64    {        1,        1,       52,       53}, // WEEK_OF_YEAR
65    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
66    {        1,        1,       30,       31}, // DAY_OF_MONTH
67    {        1,        1,      365,      366}, // DAY_OF_YEAR
68    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
69    {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
70    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
71    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
72    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
73    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
74    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
75    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
76    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
77    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
78    { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
79    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
80    { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
81    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
82    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
83    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
84};
85
86static const double JULIAN_EPOCH = 1721425.5;
87static const int32_t INDIAN_ERA_START  = 78;
88static const int32_t INDIAN_YEAR_START = 80;
89
90int32_t IndianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
91  return LIMITS[field][limitType];
92}
93
94/*
95 * Determine whether the given gregorian year is a Leap year
96 */
97static UBool isGregorianLeap(int32_t year)
98{
99    return ((year % 4) == 0) && (!(((year % 100) == 0) && ((year % 400) != 0)));
100}
101
102//----------------------------------------------------------------------
103// Calendar framework
104//----------------------------------------------------------------------
105
106/*
107 * Return the length (in days) of the given month.
108 *
109 * @param eyear  The year in Saka Era
110 * @param month  The month(0-based) in Indian calendar
111 */
112int32_t IndianCalendar::handleGetMonthLength(int32_t eyear, int32_t month) const {
113   if (month < 0 || month > 11) {
114      eyear += ClockMath::floorDivide(month, 12, month);
115   }
116
117   if (isGregorianLeap(eyear + INDIAN_ERA_START) && month == 0) {
118       return 31;
119   }
120
121   if (month >= 1 && month <= 5) {
122       return 31;
123   }
124
125   return 30;
126}
127
128/*
129 * Return the number of days in the given Indian year
130 *
131 * @param eyear The year in Saka Era.
132 */
133int32_t IndianCalendar::handleGetYearLength(int32_t eyear) const {
134    return isGregorianLeap(eyear + INDIAN_ERA_START) ? 366 : 365;
135}
136/*
137 * Returns the Julian Day corresponding to gregorian date
138 *
139 * @param year The Gregorian year
140 * @param month The month in Gregorian Year
141 * @param date The date in Gregorian day in month
142 */
143static double gregorianToJD(int32_t year, int32_t month, int32_t date) {
144   double julianDay = (JULIAN_EPOCH - 1) +
145      (365 * (year - 1)) +
146      uprv_floor((year - 1) / 4) +
147      (-uprv_floor((year - 1) / 100)) +
148      uprv_floor((year - 1) / 400) +
149      uprv_floor((((367 * month) - 362) / 12) +
150            ((month <= 2) ? 0 :
151             (isGregorianLeap(year) ? -1 : -2)
152            ) +
153            date);
154
155   return julianDay;
156}
157
158/*
159 * Returns the Gregorian Date corresponding to a given Julian Day
160 * @param jd The Julian Day
161 */
162static int32_t* jdToGregorian(double jd, int32_t gregorianDate[3]) {
163   double wjd, depoch, quadricent, dqc, cent, dcent, quad, dquad, yindex, yearday, leapadj;
164   int32_t year, month, day;
165   wjd = uprv_floor(jd - 0.5) + 0.5;
166   depoch = wjd - JULIAN_EPOCH;
167   quadricent = uprv_floor(depoch / 146097);
168   dqc = (int32_t)uprv_floor(depoch) % 146097;
169   cent = uprv_floor(dqc / 36524);
170   dcent = (int32_t)uprv_floor(dqc) % 36524;
171   quad = uprv_floor(dcent / 1461);
172   dquad = (int32_t)uprv_floor(dcent) % 1461;
173   yindex = uprv_floor(dquad / 365);
174   year = (int32_t)((quadricent * 400) + (cent * 100) + (quad * 4) + yindex);
175   if (!((cent == 4) || (yindex == 4))) {
176      year++;
177   }
178   yearday = wjd - gregorianToJD(year, 1, 1);
179   leapadj = ((wjd < gregorianToJD(year, 3, 1)) ? 0
180         :
181         (isGregorianLeap(year) ? 1 : 2)
182         );
183   month = (int32_t)uprv_floor((((yearday + leapadj) * 12) + 373) / 367);
184   day = (int32_t)(wjd - gregorianToJD(year, month, 1)) + 1;
185
186   gregorianDate[0] = year;
187   gregorianDate[1] = month;
188   gregorianDate[2] = day;
189
190   return gregorianDate;
191}
192
193
194//-------------------------------------------------------------------------
195// Functions for converting from field values to milliseconds....
196//-------------------------------------------------------------------------
197static double IndianToJD(int32_t year, int32_t month, int32_t date) {
198   int32_t leapMonth, gyear, m;
199   double start, jd;
200
201   gyear = year + INDIAN_ERA_START;
202
203
204   if(isGregorianLeap(gyear)) {
205      leapMonth = 31;
206      start = gregorianToJD(gyear, 3, 21);
207   }
208   else {
209      leapMonth = 30;
210      start = gregorianToJD(gyear, 3, 22);
211   }
212
213   if (month == 1) {
214      jd = start + (date - 1);
215   } else {
216      jd = start + leapMonth;
217      m = month - 2;
218
219      //m = Math.min(m, 5);
220      if (m > 5) {
221          m = 5;
222      }
223
224      jd += m * 31;
225
226      if (month >= 8) {
227         m = month - 7;
228         jd += m * 30;
229      }
230      jd += date - 1;
231   }
232
233   return jd;
234}
235
236/*
237 * Return JD of start of given month/year of Indian Calendar
238 * @param eyear The year in Indian Calendar measured from Saka Era (78 AD).
239 * @param month The month in Indian calendar
240 */
241int32_t IndianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */ ) const {
242
243   //month is 0 based; converting it to 1-based
244   int32_t imonth;
245
246    // If the month is out of range, adjust it into range, and adjust the extended eyar accordingly
247   if (month < 0 || month > 11) {
248      eyear += (int32_t)ClockMath::floorDivide(month, 12, month);
249   }
250
251   if(month == 12){
252       imonth = 1;
253   } else {
254       imonth = month + 1;
255   }
256
257   double jd = IndianToJD(eyear ,imonth, 1);
258
259   return (int32_t)jd;
260}
261
262//-------------------------------------------------------------------------
263// Functions for converting from milliseconds to field values
264//-------------------------------------------------------------------------
265
266int32_t IndianCalendar::handleGetExtendedYear() {
267    int32_t year;
268
269    if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
270        year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
271    } else {
272        year = internalGet(UCAL_YEAR, 1); // Default to year 1
273    }
274
275    return year;
276}
277
278/*
279 * Override Calendar to compute several fields specific to the Indian
280 * calendar system.  These are:
281 *
282 * <ul><li>ERA
283 * <li>YEAR
284 * <li>MONTH
285 * <li>DAY_OF_MONTH
286 * <li>EXTENDED_YEAR</ul>
287 *
288 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
289 * method is called. The getGregorianXxx() methods return Gregorian
290 * calendar equivalents for the given Julian day.
291 */
292void IndianCalendar::handleComputeFields(int32_t julianDay, UErrorCode&  /* status */) {
293    double jdAtStartOfGregYear;
294    int32_t leapMonth, IndianYear, yday, IndianMonth, IndianDayOfMonth, mday;
295    int32_t gregorianYear;      // Stores gregorian date corresponding to Julian day;
296    int32_t gd[3];
297
298    gregorianYear = jdToGregorian(julianDay, gd)[0];          // Gregorian date for Julian day
299    IndianYear = gregorianYear - INDIAN_ERA_START;            // Year in Saka era
300    jdAtStartOfGregYear = gregorianToJD(gregorianYear, 1, 1); // JD at start of Gregorian year
301    yday = (int32_t)(julianDay - jdAtStartOfGregYear);        // Day number in Gregorian year (starting from 0)
302
303    if (yday < INDIAN_YEAR_START) {
304        // Day is at the end of the preceding Saka year
305        IndianYear -= 1;
306        leapMonth = isGregorianLeap(gregorianYear - 1) ? 31 : 30; // Days in leapMonth this year, previous Gregorian year
307        yday += leapMonth + (31 * 5) + (30 * 3) + 10;
308    } else {
309        leapMonth = isGregorianLeap(gregorianYear) ? 31 : 30; // Days in leapMonth this year
310        yday -= INDIAN_YEAR_START;
311    }
312
313    if (yday < leapMonth) {
314        IndianMonth = 0;
315        IndianDayOfMonth = yday + 1;
316    } else {
317        mday = yday - leapMonth;
318        if (mday < (31 * 5)) {
319            IndianMonth = (int32_t)uprv_floor(mday / 31) + 1;
320            IndianDayOfMonth = (mday % 31) + 1;
321        } else {
322            mday -= 31 * 5;
323            IndianMonth = (int32_t)uprv_floor(mday / 30) + 6;
324            IndianDayOfMonth = (mday % 30) + 1;
325        }
326   }
327
328   internalSet(UCAL_ERA, 0);
329   internalSet(UCAL_EXTENDED_YEAR, IndianYear);
330   internalSet(UCAL_YEAR, IndianYear);
331   internalSet(UCAL_MONTH, IndianMonth);
332   internalSet(UCAL_DAY_OF_MONTH, IndianDayOfMonth);
333   internalSet(UCAL_DAY_OF_YEAR, yday + 1); // yday is 0-based
334}
335
336UBool
337IndianCalendar::inDaylightTime(UErrorCode& status) const
338{
339    // copied from GregorianCalendar
340    if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) {
341        return FALSE;
342    }
343
344    // Force an update of the state of the Calendar.
345    ((IndianCalendar*)this)->complete(status); // cast away const
346
347    return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
348}
349
350// default century
351const UDate     IndianCalendar::fgSystemDefaultCentury          = DBL_MIN;
352const int32_t   IndianCalendar::fgSystemDefaultCenturyYear      = -1;
353
354UDate           IndianCalendar::fgSystemDefaultCenturyStart     = DBL_MIN;
355int32_t         IndianCalendar::fgSystemDefaultCenturyStartYear = -1;
356
357
358UBool IndianCalendar::haveDefaultCentury() const
359{
360    return TRUE;
361}
362
363UDate IndianCalendar::defaultCenturyStart() const
364{
365    return internalGetDefaultCenturyStart();
366}
367
368int32_t IndianCalendar::defaultCenturyStartYear() const
369{
370    return internalGetDefaultCenturyStartYear();
371}
372
373UDate
374IndianCalendar::internalGetDefaultCenturyStart() const
375{
376    // lazy-evaluate systemDefaultCenturyStart
377    UBool needsUpdate;
378    {
379        Mutex m;
380        needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
381    }
382
383    if (needsUpdate) {
384        initializeSystemDefaultCentury();
385    }
386
387    // use defaultCenturyStart unless it's the flag value;
388    // then use systemDefaultCenturyStart
389
390    return fgSystemDefaultCenturyStart;
391}
392
393int32_t
394IndianCalendar::internalGetDefaultCenturyStartYear() const
395{
396    // lazy-evaluate systemDefaultCenturyStartYear
397    UBool needsUpdate;
398    {
399        Mutex m;
400
401        needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
402    }
403
404    if (needsUpdate) {
405        initializeSystemDefaultCentury();
406    }
407
408    // use defaultCenturyStart unless it's the flag value;
409    // then use systemDefaultCenturyStartYear
410
411    return    fgSystemDefaultCenturyStartYear;
412}
413
414void
415IndianCalendar::initializeSystemDefaultCentury()
416{
417    // initialize systemDefaultCentury and systemDefaultCenturyYear based
418    // on the current time.  They'll be set to 80 years before
419    // the current time.
420    // No point in locking as it should be idempotent.
421    if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury) {
422        UErrorCode status = U_ZERO_ERROR;
423
424        IndianCalendar calendar(Locale("@calendar=Indian"),status);
425        if (U_SUCCESS(status)) {
426            calendar.setTime(Calendar::getNow(), status);
427            calendar.add(UCAL_YEAR, -80, status);
428
429            UDate    newStart = calendar.getTime(status);
430            int32_t  newYear  = calendar.get(UCAL_YEAR, status);
431
432            {
433                Mutex m;
434
435                fgSystemDefaultCenturyStart = newStart;
436                fgSystemDefaultCenturyStartYear = newYear;
437            }
438        }
439
440        // We have no recourse upon failure unless we want to propagate the failure
441        // out.
442    }
443}
444
445UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IndianCalendar)
446
447U_NAMESPACE_END
448
449#endif
450
451