michael@0: /*
michael@0:  ******************************************************************************
michael@0:  * Copyright (C) 2003-2013, International Business Machines Corporation
michael@0:  * and others. All Rights Reserved.
michael@0:  ******************************************************************************
michael@0:  *
michael@0:  * File PERSNCAL.CPP
michael@0:  *
michael@0:  * Modification History:
michael@0:  *
michael@0:  *   Date        Name        Description
michael@0:  *   9/23/2003   mehran      posted to icu-design
michael@0:  *   10/1/2012   roozbeh     Fixed algorithm and heavily refactored and rewrote
michael@0:  *                           based on the implementation of Gregorian
michael@0:  *****************************************************************************
michael@0:  */
michael@0: 
michael@0: #include "persncal.h"
michael@0: 
michael@0: #if !UCONFIG_NO_FORMATTING
michael@0: 
michael@0: #include "umutex.h"
michael@0: #include "gregoimp.h" // Math
michael@0: #include <float.h>
michael@0: 
michael@0: static const int16_t kPersianNumDays[]
michael@0: = {0,31,62,93,124,155,186,216,246,276,306,336}; // 0-based, for day-in-year
michael@0: static const int8_t kPersianMonthLength[]
michael@0: = {31,31,31,31,31,31,30,30,30,30,30,29}; // 0-based
michael@0: static const int8_t kPersianLeapMonthLength[]
michael@0: = {31,31,31,31,31,31,30,30,30,30,30,30}; // 0-based
michael@0: 
michael@0: static const int32_t kPersianCalendarLimits[UCAL_FIELD_COUNT][4] = {
michael@0:     // Minimum  Greatest     Least   Maximum
michael@0:     //           Minimum   Maximum
michael@0:     {        0,        0,        0,        0}, // ERA
michael@0:     { -5000000, -5000000,  5000000,  5000000}, // YEAR
michael@0:     {        0,        0,       11,       11}, // MONTH
michael@0:     {        1,        1,       52,       53}, // WEEK_OF_YEAR
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // WEEK_OF_MONTH
michael@0:     {        1,       1,        29,       31}, // DAY_OF_MONTH
michael@0:     {        1,       1,       365,      366}, // DAY_OF_YEAR
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DAY_OF_WEEK
michael@0:     {        1,       1,         5,        5}, // DAY_OF_WEEK_IN_MONTH
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // AM_PM
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // HOUR_OF_DAY
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MINUTE
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // SECOND
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECOND
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // ZONE_OFFSET
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DST_OFFSET
michael@0:     { -5000000, -5000000,  5000000,  5000000}, // YEAR_WOY
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // DOW_LOCAL
michael@0:     { -5000000, -5000000,  5000000,  5000000}, // EXTENDED_YEAR
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // JULIAN_DAY
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // MILLISECONDS_IN_DAY
michael@0:     {/*N/A*/-1,/*N/A*/-1,/*N/A*/-1,/*N/A*/-1}, // IS_LEAP_MONTH
michael@0: };
michael@0: 
michael@0: U_NAMESPACE_BEGIN
michael@0: 
michael@0: static const int32_t PERSIAN_EPOCH = 1948320;
michael@0: 
michael@0: // Implementation of the PersianCalendar class
michael@0: 
michael@0: //-------------------------------------------------------------------------
michael@0: // Constructors...
michael@0: //-------------------------------------------------------------------------
michael@0: 
michael@0: const char *PersianCalendar::getType() const { 
michael@0:     return "persian";
michael@0: }
michael@0: 
michael@0: Calendar* PersianCalendar::clone() const {
michael@0:     return new PersianCalendar(*this);
michael@0: }
michael@0: 
michael@0: PersianCalendar::PersianCalendar(const Locale& aLocale, UErrorCode& success)
michael@0:   :   Calendar(TimeZone::createDefault(), aLocale, success)
michael@0: {
michael@0:     setTimeInMillis(getNow(), success); // Call this again now that the vtable is set up properly.
michael@0: }
michael@0: 
michael@0: PersianCalendar::PersianCalendar(const PersianCalendar& other) : Calendar(other) {
michael@0: }
michael@0: 
michael@0: PersianCalendar::~PersianCalendar()
michael@0: {
michael@0: }
michael@0: 
michael@0: //-------------------------------------------------------------------------
michael@0: // Minimum / Maximum access functions
michael@0: //-------------------------------------------------------------------------
michael@0: 
michael@0: 
michael@0: int32_t PersianCalendar::handleGetLimit(UCalendarDateFields field, ELimitType limitType) const {
michael@0:     return kPersianCalendarLimits[field][limitType];
michael@0: }
michael@0: 
michael@0: //-------------------------------------------------------------------------
michael@0: // Assorted calculation utilities
michael@0: //
michael@0: 
michael@0: /**
michael@0:  * Determine whether a year is a leap year in the Persian calendar
michael@0:  */
michael@0: UBool PersianCalendar::isLeapYear(int32_t year)
michael@0: {
michael@0:     int32_t remainder;
michael@0:     ClockMath::floorDivide(25 * year + 11, 33, remainder);
michael@0:     return (remainder < 8);
michael@0: }
michael@0:     
michael@0: /**
michael@0:  * Return the day # on which the given year starts.  Days are counted
michael@0:  * from the Persian epoch, origin 0.
michael@0:  */
michael@0: int32_t PersianCalendar::yearStart(int32_t year) {
michael@0:     return handleComputeMonthStart(year,0,FALSE);
michael@0: }
michael@0:     
michael@0: /**
michael@0:  * Return the day # on which the given month starts.  Days are counted
michael@0:  * from the Persian epoch, origin 0.
michael@0:  *
michael@0:  * @param year  The Persian year
michael@0:  * @param year  The Persian month, 0-based
michael@0:  */
michael@0: int32_t PersianCalendar::monthStart(int32_t year, int32_t month) const {
michael@0:     return handleComputeMonthStart(year,month,TRUE);
michael@0: }
michael@0:     
michael@0: //----------------------------------------------------------------------
michael@0: // Calendar framework
michael@0: //----------------------------------------------------------------------
michael@0: 
michael@0: /**
michael@0:  * Return the length (in days) of the given month.
michael@0:  *
michael@0:  * @param year  The Persian year
michael@0:  * @param year  The Persian month, 0-based
michael@0:  */
michael@0: int32_t PersianCalendar::handleGetMonthLength(int32_t extendedYear, int32_t month) const {
michael@0:     // If the month is out of range, adjust it into range, and
michael@0:     // modify the extended year value accordingly.
michael@0:     if (month < 0 || month > 11) {
michael@0:         extendedYear += ClockMath::floorDivide(month, 12, month);
michael@0:     }
michael@0: 
michael@0:     return isLeapYear(extendedYear) ? kPersianLeapMonthLength[month] : kPersianMonthLength[month];
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Return the number of days in the given Persian year
michael@0:  */
michael@0: int32_t PersianCalendar::handleGetYearLength(int32_t extendedYear) const {
michael@0:     return isLeapYear(extendedYear) ? 366 : 365;
michael@0: }
michael@0:     
michael@0: //-------------------------------------------------------------------------
michael@0: // Functions for converting from field values to milliseconds....
michael@0: //-------------------------------------------------------------------------
michael@0: 
michael@0: // Return JD of start of given month/year
michael@0: int32_t PersianCalendar::handleComputeMonthStart(int32_t eyear, int32_t month, UBool /*useMonth*/) const {
michael@0:     // If the month is out of range, adjust it into range, and
michael@0:     // modify the extended year value accordingly.
michael@0:     if (month < 0 || month > 11) {
michael@0:         eyear += ClockMath::floorDivide(month, 12, month);
michael@0:     }
michael@0: 
michael@0:     int32_t julianDay = PERSIAN_EPOCH - 1 + 365 * (eyear - 1) + ClockMath::floorDivide(8 * eyear + 21, 33);
michael@0: 
michael@0:     if (month != 0) {
michael@0:         julianDay += kPersianNumDays[month];
michael@0:     }
michael@0: 
michael@0:     return julianDay;
michael@0: }
michael@0: 
michael@0: //-------------------------------------------------------------------------
michael@0: // Functions for converting from milliseconds to field values
michael@0: //-------------------------------------------------------------------------
michael@0: 
michael@0: int32_t PersianCalendar::handleGetExtendedYear() {
michael@0:     int32_t year;
michael@0:     if (newerField(UCAL_EXTENDED_YEAR, UCAL_YEAR) == UCAL_EXTENDED_YEAR) {
michael@0:         year = internalGet(UCAL_EXTENDED_YEAR, 1); // Default to year 1
michael@0:     } else {
michael@0:         year = internalGet(UCAL_YEAR, 1); // Default to year 1
michael@0:     }
michael@0:     return year;
michael@0: }
michael@0: 
michael@0: /**
michael@0:  * Override Calendar to compute several fields specific to the Persian
michael@0:  * calendar system.  These are:
michael@0:  *
michael@0:  * <ul><li>ERA
michael@0:  * <li>YEAR
michael@0:  * <li>MONTH
michael@0:  * <li>DAY_OF_MONTH
michael@0:  * <li>DAY_OF_YEAR
michael@0:  * <li>EXTENDED_YEAR</ul>
michael@0:  * 
michael@0:  * The DAY_OF_WEEK and DOW_LOCAL fields are already set when this
michael@0:  * method is called.
michael@0:  */
michael@0: void PersianCalendar::handleComputeFields(int32_t julianDay, UErrorCode &/*status*/) {
michael@0:     int32_t year, month, dayOfMonth, dayOfYear;
michael@0: 
michael@0:     int32_t daysSinceEpoch = julianDay - PERSIAN_EPOCH;
michael@0:     year = 1 + ClockMath::floorDivide(33 * daysSinceEpoch + 3, 12053);
michael@0: 
michael@0:     int32_t farvardin1 = 365 * (year - 1) + ClockMath::floorDivide(8 * year + 21, 33);
michael@0:     dayOfYear = (daysSinceEpoch - farvardin1); // 0-based
michael@0:     if (dayOfYear < 216) { // Compute 0-based month
michael@0:         month = dayOfYear / 31;
michael@0:     } else {
michael@0:         month = (dayOfYear - 6) / 30;
michael@0:     }
michael@0:     dayOfMonth = dayOfYear - kPersianNumDays[month] + 1;
michael@0:     ++dayOfYear; // Make it 1-based now
michael@0: 
michael@0:     internalSet(UCAL_ERA, 0);
michael@0:     internalSet(UCAL_YEAR, year);
michael@0:     internalSet(UCAL_EXTENDED_YEAR, year);
michael@0:     internalSet(UCAL_MONTH, month);
michael@0:     internalSet(UCAL_DAY_OF_MONTH, dayOfMonth);
michael@0:     internalSet(UCAL_DAY_OF_YEAR, dayOfYear);
michael@0: }    
michael@0: 
michael@0: UBool
michael@0: PersianCalendar::inDaylightTime(UErrorCode& status) const
michael@0: {
michael@0:     // copied from GregorianCalendar
michael@0:     if (U_FAILURE(status) || !getTimeZone().useDaylightTime()) 
michael@0:         return FALSE;
michael@0: 
michael@0:     // Force an update of the state of the Calendar.
michael@0:     ((PersianCalendar*)this)->complete(status); // cast away const
michael@0: 
michael@0:     return (UBool)(U_SUCCESS(status) ? (internalGet(UCAL_DST_OFFSET) != 0) : FALSE);
michael@0: }
michael@0: 
michael@0: // default century
michael@0: 
michael@0: static UDate           gSystemDefaultCenturyStart       = DBL_MIN;
michael@0: static int32_t         gSystemDefaultCenturyStartYear   = -1;
michael@0: static icu::UInitOnce  gSystemDefaultCenturyInit        = U_INITONCE_INITIALIZER;
michael@0: 
michael@0: UBool PersianCalendar::haveDefaultCentury() const
michael@0: {
michael@0:     return TRUE;
michael@0: }
michael@0: 
michael@0: static void U_CALLCONV initializeSystemDefaultCentury() {
michael@0:     // initialize systemDefaultCentury and systemDefaultCenturyYear based
michael@0:     // on the current time.  They'll be set to 80 years before
michael@0:     // the current time.
michael@0:     UErrorCode status = U_ZERO_ERROR;
michael@0:     PersianCalendar calendar(Locale("@calendar=persian"),status);
michael@0:     if (U_SUCCESS(status))
michael@0:     {
michael@0:         calendar.setTime(Calendar::getNow(), status);
michael@0:         calendar.add(UCAL_YEAR, -80, status);
michael@0: 
michael@0:         gSystemDefaultCenturyStart = calendar.getTime(status);
michael@0:         gSystemDefaultCenturyStartYear = calendar.get(UCAL_YEAR, status);
michael@0:     }
michael@0:     // We have no recourse upon failure unless we want to propagate the failure
michael@0:     // out.
michael@0: }
michael@0: 
michael@0: UDate PersianCalendar::defaultCenturyStart() const {
michael@0:     // lazy-evaluate systemDefaultCenturyStart
michael@0:     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
michael@0:     return gSystemDefaultCenturyStart;
michael@0: }
michael@0: 
michael@0: int32_t PersianCalendar::defaultCenturyStartYear() const {
michael@0:     // lazy-evaluate systemDefaultCenturyStartYear
michael@0:     umtx_initOnce(gSystemDefaultCenturyInit, &initializeSystemDefaultCentury);
michael@0:     return gSystemDefaultCenturyStartYear;
michael@0: }
michael@0: 
michael@0: UOBJECT_DEFINE_RTTI_IMPLEMENTATION(PersianCalendar)
michael@0: 
michael@0: U_NAMESPACE_END
michael@0: 
michael@0: #endif
michael@0: