/****************************************************************************

** 

**

** Implementation of date and time classes

**

** Created : 940124

**

** Copyright (C) 1992-2000 Trolltech AS.  All rights reserved.

**

** This file is part of the tools module of the Qt GUI Toolkit.

**

** This file may be distributed under the terms of the Q Public License

** as defined by Trolltech AS of Norway and appearing in the file

** LICENSE.QPL included in the packaging of this file.

**

** This file may be distributed and/or modified under the terms of the

** GNU General Public License version 2 as published by the Free Software

** Foundation and appearing in the file LICENSE.GPL included in the

** packaging of this file.

**

** Licensees holding valid Qt Enterprise Edition or Qt Professional Edition

** licenses may use this file in accordance with the Qt Commercial License

** Agreement provided with the Software.

**

** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE

** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.

**

** See http://www.trolltech.com/pricing.html or email sales@trolltech.com for

**   information about Qt Commercial License Agreements.

** See http://www.trolltech.com/qpl/ for QPL licensing information.

** See http://www.trolltech.com/gpl/ for GPL licensing information.

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**********************************************************************/

#define gettimeofday	__hide_gettimeofday

#include "qdatetime.h"

#include "qdatastream.h"

#include <stdio.h>

#include <time.h>

#if defined(_OS_WIN32_)

#if defined(_CC_BOOL_DEF_)

#undef	bool

#include <windows.h>

#define bool int

#else

#include <windows.h>

#endif

#elif defined(_OS_MSDOS_)

#include <dos.h>

#elif defined(_OS_OS2_)

#include <os2.h>

#elif defined(_OS_UNIX_) || defined(_OS_MAC_)

#include <sys/time.h>

#include <unistd.h>

#undef	gettimeofday

extern "C" int gettimeofday( struct timeval *, struct timezone * );

#endif

static const uint FIRST_DAY	= 2361222;	// Julian day for 1752/09/14

static const int  FIRST_YEAR	= 1752;		// ### wrong for many countries

static const uint SECS_PER_DAY	= 86400;

static const uint MSECS_PER_DAY = 86400000;

static const uint SECS_PER_HOUR = 3600;

static const uint MSECS_PER_HOUR= 3600000;

static const uint SECS_PER_MIN	= 60;

static const uint MSECS_PER_MIN = 60000;

static const short monthDays[] ={0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31};

// ##### Localize.

const char * const QDate::monthNames[] = {

    "Jan", "Feb", "Mar", "Apr", "May", "Jun",

    "Jul", "Aug", "Sep", "Oct", "Nov", "Dec" };

const char * const QDate::weekdayNames[] ={

    "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun" };

/*****************************************************************************

  QDate member functions

 *****************************************************************************/

// REVISED: aavit

/*!

  \class QDate qdatetime.h

  \brief The QDate class provides date functions.

  \ingroup time

  A QDate object contains a calendar date, i.e. year, month, and day

  numbers in the modern western (Gregorian) calendar. It can read the

  current date from the system clock. It provides functions for

  comparing dates and for manipulating a date by adding a number of

  days.

  A QDate object is typically created either by giving the year, month

  and day numbers explicitly, or by using the static function

  currentDate(), which makes a QDate object which contains the

  system's clock date. An explicit date can also be set using

  setYMD().

  The year(), month(), and day() functions provide access to the year,

  month, and day numbers. Also, dayOfWeek() and dayOfYear() functions

  are provided. The same information is provided in textual format by

  the toString(), dayName(), and monthName() functions.

  QDate provides a full set of operators to compare two QDate

  objects. A date is considered smaller than another if it is earlier

  than the other.

  The date a given number of days later than a given date can be found

  using the addDays() function. Correspondingly, the number of days

  between two dates can be found using the daysTo() function.

  The daysInMonth() and daysInYear() functions tell how many days

  there are in this date's month and year, respectively. The

  isLeapYear() function tells whether this date is in a leap year.

  Note that QDate may not be used for date calculations for dates in

  the remote past, i.e. prior to the introduction of the Gregorian

  calendar. This calendar was adopted by England Sep. 14. 1752 (hence

  this is the earliest valid QDate), and subsequently by most other

  western countries, until 1923.

  The end of time is reached around 8000AD, by which time we expect Qt

  to be obsolete.

  \sa QTime, QDateTime

*/

/*!

  \fn QDate::QDate()

  Constructs a null date. Null dates are invalid.

  \sa isNull(), isValid()

*/

/*!

  Constructs a date with the year \a y, month \a m and day \a d.

  \a y must be in the range 1752-ca. 8000, \a m must be in the range

  1-12, and \a d must be in the range 1-31. Exception: if \a y is in

  the range 0-99, it is interpreted as 1900-1999.

  \sa isValid()

*/

QDate::QDate( int y, int m, int d )

{

    jd = 0;

    setYMD( y, m, d );

}

/*!

  \fn bool QDate::isNull() const

  Returns TRUE if the date is null.  A null date is invalid.

  \sa isValid()

*/

/*!

  Returns TRUE if this date is valid.

  \sa isNull()

*/

bool QDate::isValid() const

{

    return jd >= FIRST_DAY;

}

/*!

  Returns the year (>= 1752) of this date.

  \sa month(), day()

*/

int QDate::year() const

{

    int y, m, d;

    jul2greg( jd, y, m, d );

    return y;

}

/*!

  Returns the month (January=1 .. December=12) of this date.

  \sa year(), day()

*/

int QDate::month() const

{

    int y, m, d;

    jul2greg( jd, y, m, d );

    return m;

}

/*!

  Returns the day of the month (1..31) of this date.

  \sa year(), month(), dayOfWeek()

*/

int QDate::day() const

{

    int y, m, d;

    jul2greg( jd, y, m, d );

    return d;

}

/*!

  Returns the weekday (Monday=1 .. Sunday=7) for this date.

  \sa day(), dayOfYear()

*/

int QDate::dayOfWeek() const

{

    return (((jd+1) % 7) + 6)%7 + 1;

}

/*!

  Returns the day of the year (1..365) for this date.

  \sa day(), dayOfWeek()

*/

int QDate::dayOfYear() const

{

    return jd - greg2jul(year(), 1, 1) + 1;

}

/*!

  Returns the number of days in the month (28..31) for this date.

  \sa day(), daysInYear()

*/

int QDate::daysInMonth() const

{

    int y, m, d;

    jul2greg( jd, y, m, d );

    if ( m == 2 && leapYear(y) )

	return 29;

    else

	return monthDays[m];

}

/*!

  Returns the number of days in the year (365 or 366) for this date.

  \sa day(), daysInMonth()

*/

int QDate::daysInYear() const

{

    int y, m, d;

    jul2greg( jd, y, m, d );

    return leapYear(y) ? 366 : 365;

}

/*!

  Returns the name of the \a month.

  Month 1 == "Jan", month 2 == "Feb" etc.

  \sa toString(), dayName()

*/

QString QDate::monthName( int month ) const

{

#if defined(CHECK_RANGE)

    if ( month < 1 || month > 12 ) {

	qWarning( "QDate::monthName: Parameter out ouf range." );

	month = 1;

    }

#endif

    // ### Remove the fromLatin1 during localization

    return QString::fromLatin1(monthNames[month-1]);

}

/*!

  Returns the name of the \a weekday.

  Weekday 1 == "Mon", day 2 == "Tue" etc.

  \sa toString(), monthName()

*/

QString QDate::dayName( int weekday ) const

{

#if defined(CHECK_RANGE)

    if ( weekday < 1 || weekday > 7 ) {

	qWarning( "QDate::dayName: Parameter out of range." );

	weekday = 1;

    }

#endif

    // ### Remove the fromLatin1 during localization

    return QString::fromLatin1(weekdayNames[weekday-1]);

}

/*!

  Returns the date as a string.

  The string format is "Sat May 20 1995". This function uses the

  dayName() and monthName() functions to generate the string.

  \sa dayName(), monthName()

*/

QString QDate::toString() const

{

    int y, m, d;

    jul2greg( jd, y, m, d );

    QString buf = dayName(dayOfWeek());

    buf += ' ';

    buf += monthName(m);

    QString t;

    t.sprintf( " %d %d", d, y);

    buf += t;

    return buf;

}

/*!

  Sets the year \a y, month \a m and day \a d.

  \a y must be in the range 1752-ca. 8000, \a m must be in the range

  1-12, and \a d must be in the range 1-31. Exception: if \a y is in

  the range 0-99, it is interpreted as 1900-1999.

  Returns TRUE if the date is valid, otherwise FALSE.

*/

bool QDate::setYMD( int y, int m, int d )

{

    if ( !isValid(y,m,d) ) {

#if defined(CHECK_RANGE)

	 qWarning( "QDate::setYMD: Invalid date %04d/%02d/%02d", y, m, d );

#endif

	 return FALSE;

    }

    jd = greg2jul( y, m, d );

#if defined(DEBUG)

    ASSERT( year() == (y > 99 ? y : 1900+y) && month() == m && day() == d );

#endif

    return TRUE;

}

/*!

  Returns a QDate object containing a date \a ndays later than the

  date of this object (or earlier if \a ndays is negative).

  \sa daysTo()

*/

QDate QDate::addDays( int ndays ) const

{

    QDate d;

    d.jd = jd + ndays;

    return d;

}

/*!

  Returns the number of days from this date to \a d (which is negative

  if \a d is earlier than this date).

  Example:

  \code

    QDate d1( 1995, 5, 17 );		// May 17th 1995

    QDate d2( 1995, 5, 20 );		// May 20th 1995

    d1.daysTo( d2 );			// returns 3

    d2.daysTo( d1 );			// returns -3

  \endcode

  \sa addDays()

*/

int QDate::daysTo( const QDate &d ) const

{

    return d.jd - jd;

}

/*!

  \fn bool QDate::operator==( const QDate &d ) const

  Returns TRUE if this date is equal to \a d, or FALSE if

  they are different.

*/

/*!

  \fn bool QDate::operator!=( const QDate &d ) const

  Returns TRUE if this date is different from \a d, or FALSE if

  they are equal.

*/

/*!

  \fn bool QDate::operator<( const QDate &d ) const

  Returns TRUE if this date is earlier than \a d, otherwise FALSE.

*/

/*!

  \fn bool QDate::operator<=( const QDate &d ) const

  Returns TRUE if this date is earlier than or equal to \a d, otherwise FALSE.

*/

/*!

  \fn bool QDate::operator>( const QDate &d ) const

  Returns TRUE if this date is later than \a d, otherwise FALSE.

*/

/*!

  \fn bool QDate::operator>=( const QDate &d ) const

  Returns TRUE if this date is later than or equal to \a d, otherwise FALSE.

*/

/*!

  Returns the current date, as reported by the system clock.

  \sa QTime::currentTime(), QDateTime::currentDateTime()

*/

QDate QDate::currentDate()

{

#if defined(_OS_WIN32_)

    SYSTEMTIME t;

    GetLocalTime( &t );

    QDate d;

    d.jd = greg2jul( t.wYear, t.wMonth, t.wDay );

    return d;

#else

    time_t ltime;

    time( &ltime );

    tm *t = localtime( &ltime );

    QDate d;

    d.jd = greg2jul( t->tm_year + 1900, t->tm_mon + 1, t->tm_mday );

    return d;

#endif

}

/*!

  Returns TRUE if the specified date (year \a y, month \a m and day \a

  d) is valid.

  Example:

  \code

    QDate::isValid( 2002, 5, 17 );	// TRUE;  May 17th 2002 is OK.

    QDate::isValid( 2002, 2, 30 );	// FALSE; Feb 30th does not exist

    QDate::isValid( 2004, 2, 29 );	// TRUE; 2004 is a leap year

    QDate::isValid( 1202, 6, 6 );	// FALSE; 1202 is pre-Gregorian

  \endcode

  Note that a \a y value in the range 00-99 is interpreted as

  1900-1999.

  \sa isNull(), setYMD()

*/

bool QDate::isValid( int y, int m, int d )

{

    if ( y >= 0 && y <= 99 )

	y += 1900;

    else if ( y < FIRST_YEAR || (y == FIRST_YEAR && (m < 9 ||

						    (m == 9 && d < 14))) )

	return FALSE;

    return (d > 0 && m > 0 && m <= 12) &&

	   (d <= monthDays[m] || (d == 29 && m == 2 && leapYear(y)));

}

/*!

  Returns TRUE if the specified year \a y is a leap year.

*/

bool QDate::leapYear( int y )

{

    return (y % 4 == 0 && y % 100 != 0) || (y % 400 == 0);

}

/*!

  \internal

  Converts a Gregorian date to a Julian day.

  This algorithm is taken from Communications of the ACM, Vol 6, No 8.

  \sa jul2greg()

*/

uint QDate::greg2jul( int y, int m, int d )

{

    uint c, ya;

    if ( y <= 99 )

	y += 1900;

    if ( m > 2 ) {

	m -= 3;

    } else {

	m += 9;

	y--;

    }

    c = y;					// NOTE: Sym C++ 6.0 bug

    c /= 100;

    ya = y - 100*c;

    return 1721119 + d + (146097*c)/4 + (1461*ya)/4 + (153*m+2)/5;

}

/*!

  \internal

  Converts a Julian day to a Gregorian date.

  This algorithm is taken from Communications of the ACM, Vol 6, No 8.

  \sa greg2jul()

*/

void QDate::jul2greg( uint jd, int &y, int &m, int &d )

{

    uint x;

    uint j = jd - 1721119;

    y = (j*4 - 1)/146097;

    j = j*4 - 146097*y - 1;

    x = j/4;

    j = (x*4 + 3) / 1461;

    y = 100*y + j;

    x = (x*4) + 3 - 1461*j;

    x = (x + 4)/4;

    m = (5*x - 3)/153;

    x = 5*x - 3 - 153*m;

    d = (x + 5)/5;

    if ( m < 10 ) {

	m += 3;

    } else {

	m -= 9;

	y++;

    }

}

/*****************************************************************************

  QTime member functions

 *****************************************************************************/

/*!

  \class QTime qdatetime.h

  \brief The QTime class provides clock time functions.

  \ingroup time

  A QTime object contains a clock time, i.e. a number of hours,

  minutes, seconds and milliseconds since midnight. It can read the

  current time from the system clock, and measure a span of elapsed

  time. It provides functions for comparing times and for manipulating

  a time by adding a number of (milli)seconds.

  QTime operates with 24-hour clock format; it has no concept of

  AM/PM. It operates with local time; it does not know anything about

  time zones or daylight savings time.

  A QTime object is typically created either by giving the number of

  hours, minutes, seconds, and milliseconds explicitly, or by using

  the static function currentTime(), which makes a QTime object which

  contains the system's clock time. Note that the accuracy depends on

  the accuracy of the underlying operating system; not all systems

  provide 1-millisecond accuracy.

  The hour(), minute(), second(), and msec() functions provide access

  to the number of hours, minutes, seconds, and milliseconds of the

  time. The same information is provided in textual format by the

  toString() function.

  QTime provides a full set of operators to compare two QTime

  objects. A time is considered smaller than another if it is earlier

  than the other.

  The time a given number of seconds or milliseconds later than a

  given time can be found using the addSecs() or addMSecs()

  functions. Correspondingly, the number of (milli)seconds between two

  times can be found using the secsTo() or msecsTo() functions.

  QTime can be used to measure a span of elapsed time using the

  start(), restart(), and elapsed() functions.

  \sa QDate, QDateTime

*/

/*!

  \fn QTime::QTime()

  Constructs the time 0 hours, minutes, seconds and milliseconds,

  i.e. 00:00:00.000 (midnight). This is a valid time.

  \sa isValid()

*/

/*!

  Constructs a time with hour \a h, minute \a m, seconds \a s and

  milliseconds \a ms.

  \a h must be in the range 0-23, \a m and \a s must be in the range

  0-59, and \a ms must be in the range 0-999.

  \sa isValid()

*/

QTime::QTime( int h, int m, int s, int ms )

{

    setHMS( h, m, s, ms );

}

/*!

  \fn bool QTime::isNull() const

  Returns TRUE if the time is equal to 00:00:00.000. A null time is valid.

  \sa isValid()

*/

/*!

  Returns TRUE if the time is valid, or FALSE if the time is invalid.

  The time 23:30:55.746 is valid, while 24:12:30 is invalid.

  \sa isNull()

*/

bool QTime::isValid() const

{

    return ds < MSECS_PER_DAY;

}

/*!

  Returns the hour part (0..23) of the time.

*/

int QTime::hour() const

{

    return ds / MSECS_PER_HOUR;

}

/*!

  Returns the minute part (0..59) of the time.

*/

int QTime::minute() const

{

    return (ds % MSECS_PER_HOUR)/MSECS_PER_MIN;

}

/*!

  Returns the second part (0..59) of the time.

*/

int QTime::second() const

{

    return (ds / 1000)%SECS_PER_MIN;

}

/*!

  Returns the millisecond part (0..999) of the time.

*/

int QTime::msec() const

{

    return ds % 1000;

}

/*!

  Returns the time of this object in a textual format. Milliseconds

  are not included. The string format is HH:MM:SS, e.g. 1 second

  before midnight would be "23:59:59".

*/

QString QTime::toString() const

{

    QString buf;

    buf.sprintf( "%.2d:%.2d:%.2d", hour(), minute(), second() );

    return buf;

}

/*!

  Sets the time to hour \a h, minute \a m, seconds \a s and

  milliseconds \a ms.

  \a h must be in the range 0-23, \a m and \a s must be in the range

  0-59, and \a ms must be in the range 0-999. Returns TRUE if the set

  time is valid, otherwise FALSE.

  \sa isValid()

*/

bool QTime::setHMS( int h, int m, int s, int ms )

{

    if ( !isValid(h,m,s,ms) ) {

#if defined(CHECK_RANGE)

	qWarning( "QTime::setHMS Invalid time %02d:%02d:%02d.%03d", h, m, s,

		 ms );

#endif

	ds = MSECS_PER_DAY;		// make this invalid

	return FALSE;

    }

    ds = (h*SECS_PER_HOUR + m*SECS_PER_MIN + s)*1000 + ms;

    return TRUE;

}

/*!

  Returns a QTime object containing a time \a nsecs seconds later than

  the time of this object (or earlier if \a ms is negative).

  Note that the time will wrap if it passes midnight.

  Example:

  \code

    QTime n( 14, 0, 0 );                // n == 14:00:00

    QTime t;

    t = n.addSecs( 70 );                // t == 14:01:10

    t = n.addSecs( -70 );               // t == 13:58:50

    t = n.addSecs( 10*60*60 + 5 );      // t == 00:00:05

    t = n.addSecs( -15*60*60 );         // t == 23:00:00

  \endcode

  \sa addMSecs(), secsTo(), QDateTime::addSecs()

*/

QTime QTime::addSecs( int nsecs ) const

{

    return addMSecs(nsecs*1000);

}

/*!

  Returns the number of seconds from this time to \a t (which is

  negative if \a t is earlier than this time).

  Since QTime measures time within a day and there are 86400 seconds

  in a day, the result is between -86400 and 86400.

  \sa addSecs() QDateTime::secsTo()

*/

int QTime::secsTo( const QTime &t ) const

{

    return ((int)t.ds - (int)ds)/1000;

}

/*!

  Returns a QTime object containing a time \a ms milliseconds later than

  the time of this object (or earlier if \a ms is negative).

  Note that the time will wrap if it passes midnight. See addSecs()

  for an example.

  \sa addSecs(), msecsTo()

*/

QTime QTime::addMSecs( int ms ) const

{

    QTime t;

    if ( ms < 0 ) {

	// % not well-defined for -ve, but / is.

	int negdays = (MSECS_PER_DAY-ms) / MSECS_PER_DAY;

	t.ds = ((int)ds + ms + negdays*MSECS_PER_DAY)

		% MSECS_PER_DAY;

    } else {

	t.ds = ((int)ds + ms) % MSECS_PER_DAY;

    }

    return t;

}

/*!

  Returns the number of milliseconds from this time to \a t (which is

  negative if \a t is earlier than this time).

  Since QTime measures time within a day and there are 86400000

  milliseconds in a day, the result is between -86400000 and 86400000.

  \sa secsTo()

*/

int QTime::msecsTo( const QTime &t ) const

{

    return (int)t.ds - (int)ds;

}

/*!

  \fn bool QTime::operator==( const QTime &t ) const

  Returns TRUE if this time is equal to \a t, or FALSE if they are

  different.

*/

/*!

  \fn bool QTime::operator!=( const QTime &t ) const

  Returns TRUE if this time is different from \a t, or FALSE if they

  are equal.

*/

/*!

  \fn bool QTime::operator<( const QTime &t ) const

  Returns TRUE if this time is earlier than \a t, otherwise FALSE.

*/

/*!

  \fn bool QTime::operator<=( const QTime &t ) const

  Returns TRUE if this time is earlier than or equal to \a t,

  otherwise FALSE.

*/

/*!

  \fn bool QTime::operator>( const QTime &t ) const

  Returns TRUE if this time is later than \a t, otherwise FALSE.

*/

/*!

  \fn bool QTime::operator>=( const QTime &t ) const

  Returns TRUE if this time is later than or equal to \a t, otherwise

  FALSE.

*/

/*!

  Returns the current time, as reported by the system clock.

  Note that the accuracy depends on the accuracy of the underlying

  operating system; not all systems provide 1-millisecond accuracy.

*/

QTime QTime::currentTime()

{

    QTime ct;

    currentTime( &ct );

    return ct;

}

/*!

  \internal

  Fetches the current time and returns TRUE if the time is within one

  minute after midnight, otherwise FALSE. The return value is used by

  QDateTime::currentDateTime() to ensure that the date there is correct.

*/

bool QTime::currentTime( QTime *ct )

{

    if ( !ct ) {

#if defined(CHECK_NULL)

	qWarning( "QTime::currentTime(QTime *): Null pointer not allowed" );

#endif

	return FALSE;

    }

#if defined(_OS_WIN32_)

    SYSTEMTIME t;

    GetLocalTime( &t );

    ct->ds = MSECS_PER_HOUR*t.wHour + MSECS_PER_MIN*t.wMinute +

	     1000*t.wSecond + t.wMilliseconds;

    return (t.wHour == 0 && t.wMinute == 0);

#elif defined(_OS_OS2_)