|
// ==++==
//
// Copyright (c) Microsoft Corporation. All rights reserved.
//
// ==--==
namespace System.Globalization {
using System;
using System.Diagnostics.Contracts;
////////////////////////////////////////////////////////////////////////////
//
// Notes about PersianCalendar
//
////////////////////////////////////////////////////////////////////////////
// Modern Persian calendar is a solar observation based calendar. Each new year begins on the day when the vernal equinox occurs before noon.
// The epoch is the date of the vernal equinox prior to the epoch of the Islamic calendar (Microsoft 19, 622 Julian or Microsoft 22, 622 Gregorian)
// There is no Persian year 0. Ordinary years have 365 days. Leap years have 366 days with the last month (Esfand) gaining the extra day.
/*
** Calendar support range:
** Calendar Minimum Maximum
** ========== ========== ==========
** Gregorian 0622/03/22 9999/12/31
** Persian 0001/01/01 9378/10/13
*/
[Serializable]
public class PersianCalendar : Calendar {
public static readonly int PersianEra = 1;
internal static long PersianEpoch = new DateTime(622, 3, 22).Ticks / GregorianCalendar.TicksPerDay;
const int ApproximateHalfYear = 180;
internal const int DatePartYear = 0;
internal const int DatePartDayOfYear = 1;
internal const int DatePartMonth = 2;
internal const int DatePartDay = 3;
internal const int MonthsPerYear = 12;
internal static int[] DaysToMonth = { 0, 31, 62, 93, 124, 155, 186, 216, 246, 276, 306, 336, 366 };
internal const int MaxCalendarYear = 9378;
internal const int MaxCalendarMonth = 10;
internal const int MaxCalendarDay = 13;
// Persian calendar (year: 1, month: 1, day:1 ) = Gregorian (year: 622, month: 3, day: 22)
// This is the minimal Gregorian date that we support in the PersianCalendar.
internal static DateTime minDate = new DateTime(622, 3, 22);
internal static DateTime maxDate = DateTime.MaxValue;
/*=================================GetDefaultInstance==========================
**Action: Internal method to provide a default intance of PersianCalendar. Used by NLS+ implementation
** and other calendars.
**Returns:
**Arguments:
**Exceptions:
============================================================================*/
/*
internal static Calendar GetDefaultInstance() {
if (m_defaultInstance == null) {
m_defaultInstance = new PersianCalendar();
}
return (m_defaultInstance);
}
*/
public override DateTime MinSupportedDateTime
{
get
{
return (minDate);
}
}
public override DateTime MaxSupportedDateTime
{
get
{
return (maxDate);
}
}
// Return the type of the Persian calendar.
//
public override CalendarAlgorithmType AlgorithmType {
get {
return CalendarAlgorithmType.SolarCalendar;
}
}
// Construct an instance of Persian calendar.
public PersianCalendar() {
}
internal override int BaseCalendarID {
get {
return (CAL_GREGORIAN);
}
}
internal override int ID {
get {
return (CAL_PERSIAN);
}
}
/*=================================GetAbsoluteDatePersian==========================
**Action: Gets the Absolute date for the given Persian date. The absolute date means
** the number of days from January 1st, 1 A.D.
**Returns:
**Arguments:
**Exceptions:
============================================================================*/
long GetAbsoluteDatePersian(int year, int month, int day) {
if (year >= 1 && year <= MaxCalendarYear && month >= 1 && month <= 12)
{
int ordinalDay = DaysInPreviousMonths(month) + day - 1; // day is one based, make 0 based since this will be the number of days we add to beginning of year below
int approximateDaysFromEpochForYearStart = (int)(CalendricalCalculationsHelper.MeanTropicalYearInDays * (year - 1));
long yearStart = CalendricalCalculationsHelper.PersianNewYearOnOrBefore(PersianEpoch + approximateDaysFromEpochForYearStart + ApproximateHalfYear);
yearStart += ordinalDay;
return yearStart;
}
throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay"));
}
static internal void CheckTicksRange(long ticks) {
if (ticks < minDate.Ticks || ticks > maxDate.Ticks) {
throw new ArgumentOutOfRangeException(
"time",
String.Format(
CultureInfo.InvariantCulture,
Environment.GetResourceString("ArgumentOutOfRange_CalendarRange"),
minDate,
maxDate));
}
}
static internal void CheckEraRange(int era) {
if (era != CurrentEra && era != PersianEra) {
throw new ArgumentOutOfRangeException("era", Environment.GetResourceString("ArgumentOutOfRange_InvalidEraValue"));
}
}
static internal void CheckYearRange(int year, int era) {
CheckEraRange(era);
if (year < 1 || year > MaxCalendarYear) {
throw new ArgumentOutOfRangeException(
"year",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
1,
MaxCalendarYear));
}
}
static internal void CheckYearMonthRange(int year, int month, int era) {
CheckYearRange(year, era);
if (year == MaxCalendarYear) {
if (month > MaxCalendarMonth) {
throw new ArgumentOutOfRangeException(
"month",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
1,
MaxCalendarMonth));
}
}
if (month < 1 || month > 12) {
throw new ArgumentOutOfRangeException("month", Environment.GetResourceString("ArgumentOutOfRange_Month"));
}
}
static int MonthFromOrdinalDay(int ordinalDay)
{
Contract.Assert(ordinalDay <= 366);
int index = 0;
while (ordinalDay > DaysToMonth[index])
index++;
return index;
}
static int DaysInPreviousMonths(int month)
{
Contract.Assert(1 <= month && month <= 12);
--month; // months are one based but for calculations use 0 based
return DaysToMonth[month];
}
/*=================================GetDatePart==========================
**Action: Returns a given date part of this <i>DateTime</i>. This method is used
** to compute the year, day-of-year, month, or day part.
**Returns:
**Arguments:
**Exceptions: ArgumentException if part is incorrect.
============================================================================*/
internal int GetDatePart(long ticks, int part) {
long NumDays; // The calculation buffer in number of days.
CheckTicksRange(ticks);
//
// Get the absolute date. The absolute date is the number of days from January 1st, 1 A.D.
// 1/1/0001 is absolute date 1.
//
NumDays = ticks / GregorianCalendar.TicksPerDay + 1;
//
// Calculate the appromixate Persian Year.
//
long yearStart = CalendricalCalculationsHelper.PersianNewYearOnOrBefore(NumDays);
int y = (int)(Math.Floor(((yearStart - PersianEpoch) / CalendricalCalculationsHelper.MeanTropicalYearInDays) + 0.5)) + 1;
Contract.Assert(y >= 1);
if (part == DatePartYear)
{
return y;
}
//
// Calculate the Persian Month.
//
int ordinalDay = (int)(NumDays - CalendricalCalculationsHelper.GetNumberOfDays(this.ToDateTime(y, 1, 1, 0, 0, 0, 0, 1)));
if (part == DatePartDayOfYear)
{
return ordinalDay;
}
int m = MonthFromOrdinalDay(ordinalDay);
Contract.Assert(ordinalDay >= 1);
Contract.Assert(m >= 1 && m <= 12);
if (part == DatePartMonth)
{
return m;
}
int d = ordinalDay - DaysInPreviousMonths(m);
Contract.Assert(1 <= d);
Contract.Assert(d <= 31);
//
// Calculate the Persian Day.
//
if (part == DatePartDay)
{
return (d);
}
// Incorrect part value.
throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_DateTimeParsing"));
}
// Returns the DateTime resulting from adding the given number of
// months to the specified DateTime. The result is computed by incrementing
// (or decrementing) the year and month parts of the specified DateTime by
// value months, and, if required, adjusting the day part of the
// resulting date downwards to the last day of the resulting month in the
// resulting year. The time-of-day part of the result is the same as the
// time-of-day part of the specified DateTime.
//
// In more precise terms, considering the specified DateTime to be of the
// form y / m / d + t, where y is the
// year, m is the month, d is the day, and t is the
// time-of-day, the result is y1 / m1 / d1 + t,
// where y1 and m1 are computed by adding value months
// to y and m, and d1 is the largest value less than
// or equal to d that denotes a valid day in month m1 of year
// y1.
//
public override DateTime AddMonths(DateTime time, int months) {
if (months < -120000 || months > 120000) {
throw new ArgumentOutOfRangeException(
"months",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
-120000,
120000));
}
Contract.EndContractBlock();
// Get the date in Persian calendar.
int y = GetDatePart(time.Ticks, DatePartYear);
int m = GetDatePart(time.Ticks, DatePartMonth);
int d = GetDatePart(time.Ticks, DatePartDay);
int i = m - 1 + months;
if (i >= 0) {
m = i % 12 + 1;
y = y + i / 12;
} else {
m = 12 + (i + 1) % 12;
y = y + (i - 11) / 12;
}
int days = GetDaysInMonth(y, m);
if (d > days) {
d = days;
}
long ticks = GetAbsoluteDatePersian(y, m, d) * TicksPerDay + time.Ticks % TicksPerDay;
Calendar.CheckAddResult(ticks, MinSupportedDateTime, MaxSupportedDateTime);
return (new DateTime(ticks));
}
// Returns the DateTime resulting from adding the given number of
// years to the specified DateTime. The result is computed by incrementing
// (or decrementing) the year part of the specified DateTime by value
// years. If the month and day of the specified DateTime is 2/29, and if the
// resulting year is not a leap year, the month and day of the resulting
// DateTime becomes 2/28. Otherwise, the month, day, and time-of-day
// parts of the result are the same as those of the specified DateTime.
//
public override DateTime AddYears(DateTime time, int years) {
return (AddMonths(time, years * 12));
}
// Returns the day-of-month part of the specified DateTime. The returned
// value is an integer between 1 and 31.
//
public override int GetDayOfMonth(DateTime time) {
return (GetDatePart(time.Ticks, DatePartDay));
}
// Returns the day-of-week part of the specified DateTime. The returned value
// is an integer between 0 and 6, where 0 indicates Sunday, 1 indicates
// Monday, 2 indicates Tuesday, 3 indicates Wednesday, 4 indicates
// Thursday, 5 indicates Friday, and 6 indicates Saturday.
//
public override DayOfWeek GetDayOfWeek(DateTime time) {
return ((DayOfWeek)((int)(time.Ticks / TicksPerDay + 1) % 7));
}
// Returns the day-of-year part of the specified DateTime. The returned value
// is an integer between 1 and 366.
//
public override int GetDayOfYear(DateTime time) {
return (GetDatePart(time.Ticks, DatePartDayOfYear));
}
// Returns the number of days in the month given by the year and
// month arguments.
//
public override int GetDaysInMonth(int year, int month, int era) {
CheckYearMonthRange(year, month, era);
if ((month==MaxCalendarMonth) && (year==MaxCalendarYear)) {
return MaxCalendarDay;
}
int daysInMonth = DaysToMonth[month] - DaysToMonth[month - 1];
if ((month == MonthsPerYear) && !IsLeapYear(year))
{
Contract.Assert(daysInMonth == 30);
--daysInMonth;
}
return daysInMonth;
}
// Returns the number of days in the year given by the year argument for the current era.
//
public override int GetDaysInYear(int year, int era) {
CheckYearRange(year, era);
if (year==MaxCalendarYear) {
return DaysToMonth[MaxCalendarMonth-1] + MaxCalendarDay;
}
// Common years have 365 days. Leap years have 366 days.
return (IsLeapYear(year, CurrentEra) ? 366: 365);
}
// Returns the era for the specified DateTime value.
public override int GetEra(DateTime time) {
CheckTicksRange(time.Ticks);
return (PersianEra);
}
public override int[] Eras {
get {
return (new int[] {PersianEra});
}
}
// Returns the month part of the specified DateTime. The returned value is an
// integer between 1 and 12.
//
public override int GetMonth(DateTime time) {
return (GetDatePart(time.Ticks, DatePartMonth));
}
// Returns the number of months in the specified year and era.
public override int GetMonthsInYear(int year, int era) {
CheckYearRange(year, era);
if (year==MaxCalendarYear) {
return MaxCalendarMonth;
}
return (12);
}
// Returns the year part of the specified DateTime. The returned value is an
// integer between 1 and MaxCalendarYear.
//
public override int GetYear(DateTime time) {
return (GetDatePart(time.Ticks, DatePartYear));
}
// Checks whether a given day in the specified era is a leap day. This method returns true if
// the date is a leap day, or false if not.
//
public override bool IsLeapDay(int year, int month, int day, int era) {
// The year/month/era value checking is done in GetDaysInMonth().
int daysInMonth = GetDaysInMonth(year, month, era);
if (day < 1 || day > daysInMonth) {
throw new ArgumentOutOfRangeException(
"day",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Day"),
daysInMonth,
month));
}
return (IsLeapYear(year, era) && month == 12 && day == 30);
}
// Returns the leap month in a calendar year of the specified era. This method returns 0
// if this calendar does not have leap month, or this year is not a leap year.
//
public override int GetLeapMonth(int year, int era)
{
CheckYearRange(year, era);
return (0);
}
// Checks whether a given month in the specified era is a leap month. This method returns true if
// month is a leap month, or false if not.
//
public override bool IsLeapMonth(int year, int month, int era) {
CheckYearMonthRange(year, month, era);
return (false);
}
// Checks whether a given year in the specified era is a leap year. This method returns true if
// year is a leap year, or false if not.
//
public override bool IsLeapYear(int year, int era) {
CheckYearRange(year, era);
if (year == MaxCalendarYear)
{
return false;
}
return (GetAbsoluteDatePersian(year + 1, 1, 1) - GetAbsoluteDatePersian(year, 1, 1)) == 366;
}
// Returns the date and time converted to a DateTime value. Throws an exception if the n-tuple is invalid.
//
public override DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int era) {
// The year/month/era checking is done in GetDaysInMonth().
int daysInMonth = GetDaysInMonth(year, month, era);
if (day < 1 || day > daysInMonth) {
BCLDebug.Log("year = " + year + ", month = " + month + ", day = " + day);
throw new ArgumentOutOfRangeException(
"day",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Day"),
daysInMonth,
month));
}
long lDate = GetAbsoluteDatePersian(year, month, day);
if (lDate >= 0) {
return (new DateTime(lDate * GregorianCalendar.TicksPerDay + TimeToTicks(hour, minute, second, millisecond)));
} else {
throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay"));
}
}
private const int DEFAULT_TWO_DIGIT_YEAR_MAX = 1410;
public override int TwoDigitYearMax {
get {
if (twoDigitYearMax == -1) {
twoDigitYearMax = GetSystemTwoDigitYearSetting(ID, DEFAULT_TWO_DIGIT_YEAR_MAX);
}
return (twoDigitYearMax);
}
set {
VerifyWritable();
if (value < 99 || value > MaxCalendarYear)
{
throw new ArgumentOutOfRangeException(
"value",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
99,
MaxCalendarYear));
}
twoDigitYearMax = value;
}
}
public override int ToFourDigitYear(int year) {
if (year < 0) {
throw new ArgumentOutOfRangeException("year",
Environment.GetResourceString("ArgumentOutOfRange_NeedNonNegNum"));
}
Contract.EndContractBlock();
if (year < 100) {
return (base.ToFourDigitYear(year));
}
if (year > MaxCalendarYear) {
throw new ArgumentOutOfRangeException(
"year",
String.Format(
CultureInfo.CurrentCulture,
Environment.GetResourceString("ArgumentOutOfRange_Range"),
1,
MaxCalendarYear));
}
return (year);
}
}
}
|