1/*
2 * Copyright (C) 2003-2009, International Business Machines Corporation
3 * and others. All Rights Reserved.
4 ******************************************************************************
5 *
6 * File INDIANCAL.CPP
7 *****************************************************************************
8 */
9
10#include "indiancal.h"
11#include <stdlib.h>
12#if !UCONFIG_NO_FORMATTING
13
14#include "mutex.h"
15#include <float.h>
16#include "gregoimp.h" // Math
17#include "astro.h" // CalendarAstronomer
18#include "uhash.h"
19#include "ucln_in.h"
20
21// Debugging
22#ifdef U_DEBUG_INDIANCAL
23#include <stdio.h>
24#include <stdarg.h>
25
26#endif
27
28U_NAMESPACE_BEGIN
29
30// Implementation of the IndianCalendar class
31
32//-------------------------------------------------------------------------
33// Constructors...
34//-------------------------------------------------------------------------
35
36
37Calendar* IndianCalendar::clone() const {
38  return new IndianCalendar(*this);
39}
40
41IndianCalendar::IndianCalendar(const Locale& aLocale, UErrorCode& success)
42  :   Calendar(TimeZone::createDefault(), aLocale, success)
43{
44  setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
45}
46
47IndianCalendar::IndianCalendar(const IndianCalendar& other) : Calendar(other) {
48}
49
50IndianCalendar::~IndianCalendar()
51{
52}
53const char *IndianCalendar::getType() const {
54   return "indian";
55}
56
57static const int32_t LIMITS[UCAL_FIELD_COUNT][4] = {
58    // Minimum  Greatest     Least   Maximum
59    //           Minimum   Maximum
60    {        0,        0,        0,        0}, // ERA
61    { -5000000, -5000000,  5000000,  5000000}, // YEAR
62    {        0,        0,       11,       11}, // MONTH
63    {        1,        1,       52,       53}, // WEEK_OF_YEAR
64    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
65    {        1,        1,       30,       31}, // DAY_OF_MONTH
66    {        1,        1,      365,      366}, // DAY_OF_YEAR
67    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
68    {       -1,       -1,        5,        5}, // DAY_OF_WEEK_IN_MONTH
69    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
70    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
71    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
72    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
73    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
74    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
75    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
76    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
77    { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
78    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
79    { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
80    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
81    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
82    {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
83};
84
85static const double JULIAN_EPOCH = 1721425.5;
86static const int32_t INDIAN_ERA_START  = 78;
87static const int32_t INDIAN_YEAR_START = 80;
88
89int32_t IndianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
90  return LIMITS[field][limitType];
91}
92
93/*
94 * Determine whether the given gregorian year is a Leap year
95 */
96static UBool isGregorianLeap(int32_t year)
97{
98    return ((year % 4) == 0) && (!(((year % 100) == 0) && ((year % 400) != 0)));
99}
100
101//----------------------------------------------------------------------
102// Calendar framework
103//----------------------------------------------------------------------
104
105/*
106 * Return the length (in days) of the given month.
107 *
108 * @param eyear  The year in Saka Era
109 * @param month  The month(0-based) in Indian calendar
110 */
111int32_t IndianCalendar::handleGetMonthLength(int32_t eyear, int32_t month) const {
112   if (month < 0 || month > 11) {
113      eyear += ClockMath::floorDivide(month, 12, month);
114   }
115
116   if (isGregorianLeap(eyear + INDIAN_ERA_START) && month == 0) {
117       return 31;
118   }
119
120   if (month >= 1 && month <= 5) {
121       return 31;
122   }
123
124   return 30;
125}
126
127/*
128 * Return the number of days in the given Indian year
129 *
130 * @param eyear The year in Saka Era.
131 */
132int32_t IndianCalendar::handleGetYearLength(int32_t eyear) const {
133    return isGregorianLeap(eyear + INDIAN_ERA_START) ? 366 : 365;
134}
135/*
136 * Returns the Julian Day corresponding to gregorian date
137 *
138 * @param year The Gregorian year
139 * @param month The month in Gregorian Year
140 * @param date The date in Gregorian day in month
141 */
142static double gregorianToJD(int32_t year, int32_t month, int32_t date) {
143   double julianDay = (JULIAN_EPOCH - 1) +
144      (365 * (year - 1)) +
145      uprv_floor((year - 1) / 4) +
146      (-uprv_floor((year - 1) / 100)) +
147      uprv_floor((year - 1) / 400) +
148      uprv_floor((((367 * month) - 362) / 12) +
149            ((month <= 2) ? 0 :
150             (isGregorianLeap(year) ? -1 : -2)
151            ) +
152            date);
153
154   return julianDay;
155}
156
157/*
158 * Returns the Gregorian Date corresponding to a given Julian Day
159 * @param jd The Julian Day
160 */
161static int32_t* jdToGregorian(double jd, int32_t gregorianDate[3]) {
162   double wjd, depoch, quadricent, dqc, cent, dcent, quad, dquad, yindex, yearday, leapadj;
163   int32_t year, month, day;
164   wjd = uprv_floor(jd - 0.5) + 0.5;
165   depoch = wjd - JULIAN_EPOCH;
166   quadricent = uprv_floor(depoch / 146097);
167   dqc = (int32_t)uprv_floor(depoch) % 146097;
168   cent = uprv_floor(dqc / 36524);
169   dcent = (int32_t)uprv_floor(dqc) % 36524;
170   quad = uprv_floor(dcent / 1461);
171   dquad = (int32_t)uprv_floor(dcent) % 1461;
172   yindex = uprv_floor(dquad / 365);
173   year = (int32_t)((quadricent * 400) + (cent * 100) + (quad * 4) + yindex);
174   if (!((cent == 4) || (yindex == 4))) {
175      year++;
176   }
177   yearday = wjd - gregorianToJD(year, 1, 1);
178   leapadj = ((wjd < gregorianToJD(year, 3, 1)) ? 0
179         :
180         (isGregorianLeap(year) ? 1 : 2)
181         );
182   month = (int32_t)uprv_floor((((yearday + leapadj) * 12) + 373) / 367);
183   day = (int32_t)(wjd - gregorianToJD(year, month, 1)) + 1;
184
185   gregorianDate[0] = year;
186   gregorianDate[1] = month;
187   gregorianDate[2] = day;
188
189   return gregorianDate;
190}
191
192
193//-------------------------------------------------------------------------
194// Functions for converting from field values to milliseconds....
195//-------------------------------------------------------------------------
196static double IndianToJD(int32_t year, int32_t month, int32_t date) {
197   int32_t leapMonth, gyear, m;
198   double start, jd;
199
200   gyear = year + INDIAN_ERA_START;
201
202
203   if(isGregorianLeap(gyear)) {
204      leapMonth = 31;
205      start = gregorianToJD(gyear, 3, 21);
206   }
207   else {
208      leapMonth = 30;
209      start = gregorianToJD(gyear, 3, 22);
210   }
211
212   if (month == 1) {
213      jd = start + (date - 1);
214   } else {
215      jd = start + leapMonth;
216      m = month - 2;
217
218      //m = Math.min(m, 5);
219      if (m > 5) {
220          m = 5;
221      }
222
223      jd += m * 31;
224
225      if (month >= 8) {
226         m = month - 7;
227         jd += m * 30;
228      }
229      jd += date - 1;
230   }
231
232   return jd;
233}
234
235/*
236 * Return JD of start of given month/year of Indian Calendar
237 * @param eyear The year in Indian Calendar measured from Saka Era (78 AD).
238 * @param month The month in Indian calendar
239 */
240int32_t IndianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /* useMonth */ ) const {
241
242   //month is 0 based; converting it to 1-based
243   int32_t imonth;
244
245    // If the month is out of range, adjust it into range, and adjust the extended eyar accordingly
246   if (month < 0 || month > 11) {
247      eyear += (int32_t)ClockMath::floorDivide(month, 12, month);
248   }
249
250   if(month == 12){
251       imonth = 1;
252   } else {
253       imonth = month + 1;
254   }
255
256   double jd = IndianToJD(eyear ,imonth, 1);
257
258   return (int32_t)jd;
259}
260
261//-------------------------------------------------------------------------
262// Functions for converting from milliseconds to field values
263//-------------------------------------------------------------------------
264
265int32_t IndianCalendar::handleGetExtendedYear() {
266    int32_t year;
267
268    if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
269        year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
270    } else {
271        year = internalGet(UCAL_YEAR, 1); // Default to year 1
272    }
273
274    return year;
275}
276
277/*
278 * Override Calendar to compute several fields specific to the Indian
279 * calendar system.  These are:
280 *
281 * <ul><li>ERA
282 * <li>YEAR
283 * <li>MONTH
284 * <li>DAY_OF_MONTH
285 * <li>EXTENDED_YEAR</ul>
286 *
287 * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
288 * method is called. The getGregorianXxx() methods return Gregorian
289 * calendar equivalents for the given Julian day.
290 */
291void IndianCalendar::handleComputeFields(int32_t julianDay, UErrorCode&  /* status */) {
292    double jdAtStartOfGregYear;
293    int32_t leapMonth, IndianYear, yday, IndianMonth, IndianDayOfMonth, mday;
294    int32_t gregorianYear;      // Stores gregorian date corresponding to Julian day;
295    int32_t gd[3];
296
297    gregorianYear = jdToGregorian(julianDay, gd)[0];          // Gregorian date for Julian day
298    IndianYear = gregorianYear - INDIAN_ERA_START;            // Year in Saka era
299    jdAtStartOfGregYear = gregorianToJD(gregorianYear, 1, 1); // JD at start of Gregorian year
300    yday = (int32_t)(julianDay - jdAtStartOfGregYear);        // Day number in Gregorian year (starting from 0)
301
302    if (yday < INDIAN_YEAR_START) {
303        // Day is at the end of the preceding Saka year
304        IndianYear -= 1;
305        leapMonth = isGregorianLeap(gregorianYear - 1) ? 31 : 30; // Days in leapMonth this year, previous Gregorian year
306        yday += leapMonth + (31 * 5) + (30 * 3) + 10;
307    } else {
308        leapMonth = isGregorianLeap(gregorianYear) ? 31 : 30; // Days in leapMonth this year
309        yday -= INDIAN_YEAR_START;
310    }
311
312    if (yday < leapMonth) {
313        IndianMonth = 0;
314        IndianDayOfMonth = yday + 1;
315    } else {
316        mday = yday - leapMonth;
317        if (mday < (31 * 5)) {
318            IndianMonth = (int32_t)uprv_floor(mday / 31) + 1;
319            IndianDayOfMonth = (mday % 31) + 1;
320        } else {
321            mday -= 31 * 5;
322            IndianMonth = (int32_t)uprv_floor(mday / 30) + 6;
323            IndianDayOfMonth = (mday % 30) + 1;
324        }
325   }
326
327   internalSet(UCAL_ERA, 0);
328   internalSet(UCAL_EXTENDED_YEAR, IndianYear);
329   internalSet(UCAL_YEAR, IndianYear);
330   internalSet(UCAL_MONTH, IndianMonth);
331   internalSet(UCAL_DAY_OF_MONTH, IndianDayOfMonth);
332   internalSet(UCAL_DAY_OF_YEAR, yday + 1); // yday is 0-based
333}
334
335UBool
336IndianCalendar::inDaylightTime(UErrorCode& status) const
337{
338    // copied from GregorianCalendar
339    if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) {
340        return FALSE;
341    }
342
343    // Force an update of the state of the Calendar.
344    ((IndianCalendar*)this)->complete(status); // cast away const
345
346    return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
347}
348
349// default century
350const UDate     IndianCalendar::fgSystemDefaultCentury          = DBL_MIN;
351const int32_t   IndianCalendar::fgSystemDefaultCenturyYear      = -1;
352
353UDate           IndianCalendar::fgSystemDefaultCenturyStart     = DBL_MIN;
354int32_t         IndianCalendar::fgSystemDefaultCenturyStartYear = -1;
355
356
357UBool IndianCalendar::haveDefaultCentury() const
358{
359    return TRUE;
360}
361
362UDate IndianCalendar::defaultCenturyStart() const
363{
364    return internalGetDefaultCenturyStart();
365}
366
367int32_t IndianCalendar::defaultCenturyStartYear() const
368{
369    return internalGetDefaultCenturyStartYear();
370}
371
372UDate
373IndianCalendar::internalGetDefaultCenturyStart() const
374{
375    // lazy-evaluate systemDefaultCenturyStart
376    UBool needsUpdate;
377    {
378        Mutex m;
379        needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
380    }
381
382    if (needsUpdate) {
383        initializeSystemDefaultCentury();
384    }
385
386    // use defaultCenturyStart unless it's the flag value;
387    // then use systemDefaultCenturyStart
388
389    return fgSystemDefaultCenturyStart;
390}
391
392int32_t
393IndianCalendar::internalGetDefaultCenturyStartYear() const
394{
395    // lazy-evaluate systemDefaultCenturyStartYear
396    UBool needsUpdate;
397    {
398        Mutex m;
399
400        needsUpdate = (fgSystemDefaultCenturyStart == fgSystemDefaultCentury);
401    }
402
403    if (needsUpdate) {
404        initializeSystemDefaultCentury();
405    }
406
407    // use defaultCenturyStart unless it's the flag value;
408    // then use systemDefaultCenturyStartYear
409
410    return    fgSystemDefaultCenturyStartYear;
411}
412
413void
414IndianCalendar::initializeSystemDefaultCentury()
415{
416    // initialize systemDefaultCentury and systemDefaultCenturyYear based
417    // on the current time.  They'll be set to 80 years before
418    // the current time.
419    // No point in locking as it should be idempotent.
420    if (fgSystemDefaultCenturyStart == fgSystemDefaultCentury) {
421        UErrorCode status = U_ZERO_ERROR;
422
423        IndianCalendar calendar(Locale("@calendar=Indian"),status);
424        if (U_SUCCESS(status)) {
425            calendar.setTime(Calendar::getNow(), status);
426            calendar.add(UCAL_YEAR, -80, status);
427
428            UDate    newStart = calendar.getTime(status);
429            int32_t  newYear  = calendar.get(UCAL_YEAR, status);
430
431            {
432                Mutex m;
433
434                fgSystemDefaultCenturyStart = newStart;
435                fgSystemDefaultCenturyStartYear = newYear;
436            }
437        }
438
439        // We have no recourse upon failure unless we want to propagate the failure
440        // out.
441    }
442}
443
444UOBJECT_DEFINE_RTTI_IMPLEMENTATION(IndianCalendar)
445
446U_NAMESPACE_END
447
448#endif
449
450