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