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+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed
+ * with this work for additional information regarding copyright
+ * ownership. The ASF licenses this file to you under the Apache
+ * License, Version 2.0 (the "License"); you may not use this file
+ * except in compliance with the License. You may obtain a copy of
+ * the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+#include <tools/date.hxx>
+#include <sal/log.hxx>
+#include <com/sun/star/util/DateTime.hpp>
+
+#include <systemdatetime.hxx>
+
+const sal_uInt16 aDaysInMonth[12] = { 31, 28, 31, 30, 31, 30,
+ 31, 31, 30, 31, 30, 31 };
+
+// Once upon a time the number of days we internally handled was limited to
+// MAX_DAYS 3636532. That changed with a full 16-bit year.
+// Assuming the first valid positive date in a proleptic Gregorian calendar is
+// 0001-01-01, this resulted in an end date of 9957-06-26.
+// Hence we documented that years up to and including 9956 are handled.
+/* XXX: it is unclear history why this value was chosen, the representable
+ * 9999-12-31 would be 3652060 days from 0001-01-01. Even 9998-12-31 to
+ * distinguish from a maximum possible date would be 3651695.
+ * There is connectivity/source/commontools/dbconversion.cxx that still has the
+ * same value to calculate with css::util::Date */
+/* XXX can that dbconversion cope with years > 9999 or negative years at all?
+ * Database fields may be limited to positive 4 digits. */
+
+const sal_Int32 MIN_DAYS = -11968265; // -32768-01-01
+const sal_Int32 MAX_DAYS = 11967900; // 32767-12-31
+
+namespace
+{
+
+const sal_Int16 kYearMax = SAL_MAX_INT16;
+const sal_Int16 kYearMin = SAL_MIN_INT16;
+
+// Days until start of year from zero, so month and day of month can be added.
+// year 1 => 0 days, year 2 => 365 days, ...
+// year -1 => -366 days, year -2 => -731 days, ...
+sal_Int32 ImpYearToDays( sal_Int16 nYear )
+{
+ assert( nYear != 0 );
+ sal_Int32 nOffset;
+ sal_Int32 nYr;
+ if (nYear < 0)
+ {
+ nOffset = -366;
+ nYr = nYear + 1;
+ }
+ else
+ {
+ nOffset = 0;
+ nYr = nYear - 1;
+ }
+ return nOffset + nYr*365 + nYr/4 - nYr/100 + nYr/400;
+}
+
+bool ImpIsLeapYear( sal_Int16 nYear )
+{
+ // Leap years BCE are -1, -5, -9, ...
+ // See
+ // https://en.wikipedia.org/wiki/Proleptic_Gregorian_calendar#Usage
+ // https://en.wikipedia.org/wiki/0_(year)#History_of_astronomical_usage
+ assert( nYear != 0 );
+ if (nYear < 0)
+ nYear = -nYear - 1;
+ return ( ( ((nYear % 4) == 0) && ((nYear % 100) != 0) ) ||
+ ( (nYear % 400) == 0 ) );
+}
+
+// All callers must have sanitized or normalized month and year values!
+sal_uInt16 ImplDaysInMonth( sal_uInt16 nMonth, sal_Int16 nYear )
+{
+ if ( nMonth != 2 )
+ return aDaysInMonth[nMonth-1];
+ else
+ {
+ if (ImpIsLeapYear(nYear))
+ return aDaysInMonth[nMonth-1] + 1;
+ else
+ return aDaysInMonth[nMonth-1];
+ }
+}
+
+}
+
+void Date::setDateFromDMY( sal_uInt16 nDay, sal_uInt16 nMonth, sal_Int16 nYear )
+{
+ // don't warn about 0/0/0, commonly used as a default-value/no-value
+ SAL_WARN_IF( nYear == 0 && !(nYear == 0 && nMonth == 0 && nDay == 0),
+ "tools.datetime", "Date::setDateFromDMY - sure about 0 year? It's not in the calendar.");
+ assert( nMonth < 100 && "nMonth % 100 not representable" );
+ assert( nDay < 100 && "nDay % 100 not representable" );
+ if (nYear < 0)
+ mnDate =
+ (static_cast<sal_Int32>( nYear ) * 10000) -
+ (static_cast<sal_Int32>( nMonth % 100 ) * 100) -
+ static_cast<sal_Int32>( nDay % 100 );
+ else
+ mnDate =
+ (static_cast<sal_Int32>( nYear ) * 10000) +
+ (static_cast<sal_Int32>( nMonth % 100 ) * 100) +
+ static_cast<sal_Int32>( nDay % 100 );
+}
+
+void Date::SetDate( sal_Int32 nNewDate )
+{
+ assert( ((nNewDate / 10000) != 0) && "you don't want to set a 0 year, do you?" );
+ mnDate = nNewDate;
+}
+
+// static
+sal_uInt16 Date::GetDaysInMonth( sal_uInt16 nMonth, sal_Int16 nYear )
+{
+ SAL_WARN_IF( nMonth < 1 || 12 < nMonth, "tools.datetime", "Date::GetDaysInMonth - nMonth out of bounds " << nMonth);
+ if (nMonth < 1)
+ nMonth = 1;
+ else if (12 < nMonth)
+ nMonth = 12;
+ return ImplDaysInMonth( nMonth, nYear);
+}
+
+sal_Int32 Date::GetAsNormalizedDays() const
+{
+ // This is a very common datum we often calculate from.
+ if (mnDate == 18991230) // 1899-12-30
+ {
+ assert(DateToDays( GetDay(), GetMonth(), GetYear() ) == 693594);
+ return 693594;
+ }
+ return DateToDays( GetDay(), GetMonth(), GetYear() );
+}
+
+sal_Int32 Date::DateToDays( sal_uInt16 nDay, sal_uInt16 nMonth, sal_Int16 nYear )
+{
+ Normalize( nDay, nMonth, nYear);
+
+ sal_Int32 nDays = ImpYearToDays(nYear);
+ for( sal_uInt16 i = 1; i < nMonth; i++ )
+ nDays += ImplDaysInMonth(i,nYear);
+ nDays += nDay;
+ return nDays;
+}
+
+static Date lcl_DaysToDate( sal_Int32 nDays )
+{
+ if ( nDays <= MIN_DAYS )
+ return Date( 1, 1, kYearMin );
+ if ( nDays >= MAX_DAYS )
+ return Date( 31, 12, kYearMax );
+
+ // Day 0 is -0001-12-31, day 1 is 0001-01-01
+ const sal_Int16 nSign = (nDays <= 0 ? -1 : 1);
+ sal_Int32 nTempDays;
+ sal_Int32 i = 0;
+ bool bCalc;
+
+ sal_Int16 nYear;
+ do
+ {
+ nYear = static_cast<sal_Int16>((nDays / 365) - (i * nSign));
+ if (nYear == 0)
+ nYear = nSign;
+ nTempDays = nDays - ImpYearToDays(nYear);
+ bCalc = false;
+ if ( nTempDays < 1 )
+ {
+ i += nSign;
+ bCalc = true;
+ }
+ else
+ {
+ if ( nTempDays > 365 )
+ {
+ if ( (nTempDays != 366) || !ImpIsLeapYear( nYear ) )
+ {
+ i -= nSign;
+ bCalc = true;
+ }
+ }
+ }
+ }
+ while ( bCalc );
+
+ sal_uInt16 nMonth = 1;
+ while ( nTempDays > ImplDaysInMonth( nMonth, nYear ) )
+ {
+ nTempDays -= ImplDaysInMonth( nMonth, nYear );
+ ++nMonth;
+ }
+
+ return Date( static_cast<sal_uInt16>(nTempDays), nMonth, nYear );
+}
+
+Date::Date( DateInitSystem )
+{
+ if ( !GetSystemDateTime( &mnDate, nullptr ) )
+ setDateFromDMY( 1, 1, 1900 );
+}
+
+Date::Date( const css::util::DateTime& rDateTime )
+{
+ setDateFromDMY( rDateTime.Day, rDateTime.Month, rDateTime.Year );
+}
+
+void Date::SetDay( sal_uInt16 nNewDay )
+{
+ setDateFromDMY( nNewDay, GetMonth(), GetYear() );
+}
+
+void Date::SetMonth( sal_uInt16 nNewMonth )
+{
+ setDateFromDMY( GetDay(), nNewMonth, GetYear() );
+}
+
+void Date::SetYear( sal_Int16 nNewYear )
+{
+ assert( nNewYear != 0 );
+ setDateFromDMY( GetDay(), GetMonth(), nNewYear );
+}
+
+void Date::AddYears( sal_Int16 nAddYears )
+{
+ sal_Int16 nYear = GetYear();
+ if (nYear < 0)
+ {
+ if (nAddYears < 0)
+ {
+ if (nYear < kYearMin - nAddYears)
+ nYear = kYearMin;
+ else
+ nYear += nAddYears;
+ }
+ else
+ {
+ nYear += nAddYears;
+ if (nYear == 0)
+ nYear = 1;
+ }
+ }
+ else
+ {
+ if (nAddYears > 0)
+ {
+ if (kYearMax - nAddYears < nYear)
+ nYear = kYearMax;
+ else
+ nYear += nAddYears;
+ }
+ else
+ {
+ nYear += nAddYears;
+ if (nYear == 0)
+ nYear = -1;
+ }
+ }
+
+ SetYear( nYear );
+ if (GetMonth() == 2 && GetDay() == 29 && !ImpIsLeapYear( nYear))
+ SetDay(28);
+}
+
+void Date::AddMonths( sal_Int32 nAddMonths )
+{
+ sal_Int32 nMonths = GetMonth() + nAddMonths;
+ sal_Int32 nNewMonth = nMonths % 12;
+ sal_Int32 nYear = GetYear() + nMonths / 12;
+ if( nMonths <= 0 || nNewMonth == 0 )
+ --nYear;
+ if( nNewMonth <= 0 )
+ nNewMonth += 12;
+ if (nYear == 0)
+ nYear = (nAddMonths < 0 ? -1 : 1);
+ else if (nYear < kYearMin)
+ nYear = kYearMin;
+ else if (nYear > kYearMax)
+ nYear = kYearMax;
+ SetMonth( static_cast<sal_uInt16>(nNewMonth) );
+ SetYear( static_cast<sal_Int16>(nYear) );
+ Normalize();
+}
+
+DayOfWeek Date::GetDayOfWeek() const
+{
+ return static_cast<DayOfWeek>((GetAsNormalizedDays()-1) % 7);
+}
+
+sal_uInt16 Date::GetDayOfYear() const
+{
+ sal_uInt16 nDay = GetDay();
+ sal_uInt16 nMonth = GetMonth();
+ sal_Int16 nYear = GetYear();
+ Normalize( nDay, nMonth, nYear);
+
+ for( sal_uInt16 i = 1; i < nMonth; i++ )
+ nDay += ::ImplDaysInMonth( i, nYear );
+ return nDay;
+}
+
+sal_uInt16 Date::GetWeekOfYear( DayOfWeek eStartDay,
+ sal_Int16 nMinimumNumberOfDaysInWeek ) const
+{
+ short nWeek;
+ short n1WDay = static_cast<short>(Date( 1, 1, GetYear() ).GetDayOfWeek());
+ short nDayOfYear = static_cast<short>(GetDayOfYear());
+
+ // weekdays start at 0, thus decrement one
+ nDayOfYear--;
+ // account for StartDay
+ n1WDay = (n1WDay+(7-static_cast<short>(eStartDay))) % 7;
+
+ if (nMinimumNumberOfDaysInWeek < 1 || 7 < nMinimumNumberOfDaysInWeek)
+ {
+ SAL_WARN( "tools.datetime", "Date::GetWeekOfYear: invalid nMinimumNumberOfDaysInWeek" );
+ nMinimumNumberOfDaysInWeek = 4;
+ }
+
+ if ( nMinimumNumberOfDaysInWeek == 1 )
+ {
+ nWeek = ((n1WDay+nDayOfYear)/7) + 1;
+ // Set to 53rd week only if we're not in the
+ // first week of the new year
+ if ( nWeek == 54 )
+ nWeek = 1;
+ else if ( nWeek == 53 )
+ {
+ short nDaysInYear = static_cast<short>(GetDaysInYear());
+ short nDaysNextYear = static_cast<short>(Date( 1, 1, GetNextYear() ).GetDayOfWeek());
+ nDaysNextYear = (nDaysNextYear+(7-static_cast<short>(eStartDay))) % 7;
+ if ( nDayOfYear > (nDaysInYear-nDaysNextYear-1) )
+ nWeek = 1;
+ }
+ }
+ else if ( nMinimumNumberOfDaysInWeek == 7 )
+ {
+ nWeek = ((n1WDay+nDayOfYear)/7);
+ // First week of a year is equal to the last week of the previous year
+ if ( nWeek == 0 )
+ {
+ Date aLastDatePrevYear( 31, 12, GetPrevYear() );
+ nWeek = aLastDatePrevYear.GetWeekOfYear( eStartDay, nMinimumNumberOfDaysInWeek );
+ }
+ }
+ else // ( nMinimumNumberOfDaysInWeek == something_else, commentary examples for 4 )
+ {
+ // x_monday - thursday
+ if ( n1WDay < nMinimumNumberOfDaysInWeek )
+ nWeek = 1;
+ // Friday
+ else if ( n1WDay == nMinimumNumberOfDaysInWeek )
+ nWeek = 53;
+ // Saturday
+ else if ( n1WDay == nMinimumNumberOfDaysInWeek + 1 )
+ {
+ // Year after leap year
+ if ( Date( 1, 1, GetPrevYear() ).IsLeapYear() )
+ nWeek = 53;
+ else
+ nWeek = 52;
+ }
+ // Sunday
+ else
+ nWeek = 52;
+
+ if ( (nWeek == 1) || (nDayOfYear + n1WDay > 6) )
+ {
+ if ( nWeek == 1 )
+ nWeek += (nDayOfYear + n1WDay) / 7;
+ else
+ nWeek = (nDayOfYear + n1WDay) / 7;
+ if ( nWeek == 53 )
+ {
+ // next x_Sunday == first x_Sunday in the new year
+ // == still the same week!
+ sal_Int32 nTempDays = GetAsNormalizedDays();
+
+ nTempDays += 6 - (GetDayOfWeek()+(7-static_cast<short>(eStartDay))) % 7;
+ nWeek = lcl_DaysToDate( nTempDays ).GetWeekOfYear( eStartDay, nMinimumNumberOfDaysInWeek );
+ }
+ }
+ }
+
+ return static_cast<sal_uInt16>(nWeek);
+}
+
+sal_uInt16 Date::GetDaysInMonth() const
+{
+ sal_uInt16 nDay = GetDay();
+ sal_uInt16 nMonth = GetMonth();
+ sal_Int16 nYear = GetYear();
+ Normalize( nDay, nMonth, nYear);
+
+ return ImplDaysInMonth( nMonth, nYear );
+}
+
+bool Date::IsLeapYear() const
+{
+ sal_Int16 nYear = GetYear();
+ return ImpIsLeapYear( nYear );
+}
+
+bool Date::IsValidAndGregorian() const
+{
+ sal_uInt16 nDay = GetDay();
+ sal_uInt16 nMonth = GetMonth();
+ sal_Int16 nYear = GetYear();
+
+ if ( !nMonth || (nMonth > 12) )
+ return false;
+ if ( !nDay || (nDay > ImplDaysInMonth( nMonth, nYear )) )
+ return false;
+ else if ( nYear <= 1582 )
+ {
+ if ( nYear < 1582 )
+ return false;
+ else if ( nMonth < 10 )
+ return false;
+ else if ( (nMonth == 10) && (nDay < 15) )
+ return false;
+ }
+
+ return true;
+}
+
+bool Date::IsValidDate() const
+{
+ return IsValidDate( GetDay(), GetMonth(), GetYear());
+}
+
+//static
+bool Date::IsValidDate( sal_uInt16 nDay, sal_uInt16 nMonth, sal_Int16 nYear )
+{
+ if (nYear == 0)
+ return false;
+ if ( !nMonth || (nMonth > 12) )
+ return false;
+ if ( !nDay || (nDay > ImplDaysInMonth( nMonth, nYear )) )
+ return false;
+ return true;
+}
+
+bool Date::IsEndOfMonth() const
+{
+ return IsEndOfMonth(GetDay(), GetMonth(), GetYear());
+}
+
+//static
+bool Date::IsEndOfMonth(sal_uInt16 nDay, sal_uInt16 nMonth, sal_Int16 nYear)
+{
+ return IsValidDate(nDay, nMonth, nYear) && ImplDaysInMonth(nMonth, nYear) == nDay;
+}
+
+void Date::Normalize()
+{
+ sal_uInt16 nDay = GetDay();
+ sal_uInt16 nMonth = GetMonth();
+ sal_Int16 nYear = GetYear();
+
+ if (!Normalize( nDay, nMonth, nYear))
+ return;
+
+ setDateFromDMY( nDay, nMonth, nYear );
+}
+
+//static
+bool Date::Normalize( sal_uInt16 & rDay, sal_uInt16 & rMonth, sal_Int16 & rYear )
+{
+ if (IsValidDate( rDay, rMonth, rYear))
+ return false;
+
+ if (rDay == 0 && rMonth == 0 && rYear == 0)
+ return false; // empty date
+
+ if (rDay == 0)
+ {
+ if (rMonth == 0)
+ ; // nothing, handled below
+ else
+ --rMonth;
+ // Last day of month is determined at the end.
+ }
+
+ if (rMonth > 12)
+ {
+ rYear += rMonth / 12;
+ rMonth = rMonth % 12;
+ if (rYear == 0)
+ rYear = 1;
+ }
+ if (rMonth == 0)
+ {
+ --rYear;
+ if (rYear == 0)
+ rYear = -1;
+ rMonth = 12;
+ }
+
+ if (rYear < 0)
+ {
+ sal_uInt16 nDays;
+ while (rDay > (nDays = ImplDaysInMonth( rMonth, rYear)))
+ {
+ rDay -= nDays;
+ if (rMonth > 1)
+ --rMonth;
+ else
+ {
+ if (rYear == kYearMin)
+ {
+ rDay = 1;
+ rMonth = 1;
+ return true;
+ }
+ --rYear;
+ rMonth = 12;
+ }
+ }
+ }
+ else
+ {
+ sal_uInt16 nDays;
+ while (rDay > (nDays = ImplDaysInMonth( rMonth, rYear)))
+ {
+ rDay -= nDays;
+ if (rMonth < 12)
+ ++rMonth;
+ else
+ {
+ if (rYear == kYearMax)
+ {
+ rDay = 31;
+ rMonth = 12;
+ return true;
+ }
+ ++rYear;
+ rMonth = 1;
+ }
+ }
+ }
+
+ if (rDay == 0)
+ rDay = ImplDaysInMonth( rMonth, rYear);
+
+ return true;
+}
+
+void Date::AddDays( sal_Int32 nDays )
+{
+ if (nDays != 0)
+ *this = lcl_DaysToDate( GetAsNormalizedDays() + nDays );
+}
+
+Date& Date::operator ++()
+{
+ *this = lcl_DaysToDate( GetAsNormalizedDays() + 1 );
+ return *this;
+}
+
+Date& Date::operator --()
+{
+ *this = lcl_DaysToDate( GetAsNormalizedDays() - 1 );
+ return *this;
+}
+
+Date operator +( const Date& rDate, sal_Int32 nDays )
+{
+ Date aDate( rDate );
+ aDate.AddDays( nDays );
+ return aDate;
+}
+
+Date operator -( const Date& rDate, sal_Int32 nDays )
+{
+ Date aDate( rDate );
+ aDate.AddDays( -nDays );
+ return aDate;
+}
+
+sal_Int32 operator -( const Date& rDate1, const Date& rDate2 )
+{
+ return rDate1.GetAsNormalizedDays() - rDate2.GetAsNormalizedDays();
+}
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */