/////////////////////////////////////////////////////////////////////////////
// Name:        date.cpp
// Purpose:     wxDate class
// Author:
//    Originally inspired by Steve Marcus (CIS 72007,1233)  6/16/91
//    Enhanced by Eric Simon (CIS 70540,1522)               6/29/91
//    Further Enhanced by Chris Hill (CIS 72030,2606)       7/11/91
//    Still Further Enhanced by Hill & Simon  v3.10         8/05/91
//    Version 4 by Charles D. Price                         6/27/92
//    Integrated into wxWindows by Julian Smart             9th July 1995
// Modified by:
// Created:     01/02/97
// RCS-ID:      $Id$
// Copyright:   (c) Julian Smart and Markus Holzem
// Licence:     wxWindows licence
/////////////////////////////////////////////////////////////////////////////

#ifdef __GNUG__
#pragma implementation "date.h"
#endif

// For compilers that support precompilation, includes "wx.h".
#include "wx/wxprec.h"

#ifdef __BORLANDC__
#pragma hdrstop
#endif

#include "wx/setup.h"

#if wxUSE_TIMEDATE

#include "wx/date.h"
#include <wx/intl.h>

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#if wxUSE_IOSTREAMH
#include <iostream.h>
#else
#include <iostream>
#endif

#include <time.h>
#include <string.h>

#define ABBR_LENGTH 3

static const char *dayname[] = {
    "Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"
};

static const char *mname[] = {
    "January", "February", "March", "April", "May", "June", "July", "August",
    "September", "October", "November", "December"
};

static int GauDays[] = { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 };

#if !USE_SHARED_LIBRARY
IMPLEMENT_DYNAMIC_CLASS(wxDate, wxObject)
#endif

    ////////////////////////////////////////////////////////////
    // Constructors
    ////////////////////////////////////////////////////////////

wxDate::wxDate()
{
    DisplayFormat=wxMDY;
    DisplayOptions='\0';
    month = day = year = day_of_week = 0;
    julian = 0;
}

wxDate::wxDate (long j) : julian(j)
{
    DisplayFormat=wxMDY;
    DisplayOptions='\0';
    julian_to_mdy ();
}

wxDate::wxDate (int m, int d, int y) : month(m), day(d), year(y)
{
    DisplayFormat=wxMDY;
    DisplayOptions='\0';
    mdy_to_julian ();
}

wxDate::wxDate (const wxString& dat)
{
    DisplayFormat=wxMDY;
    DisplayOptions='\0';
    if (strcmp(dat, "TODAY") == 0 || strcmp(dat, "today") == 0)
    {
        // Sets the current date
        Set();
    }
    else
    {
        char buf[100];
        strcpy(buf, (char *) (const char *)dat);

        char *token = strtok(buf,"/-");
        month = atoi(token);
        day   = atoi(strtok((char *) NULL,"/-"));
        year  = atoi(strtok((char *) NULL," "));
    }

    mdy_to_julian ();
}

wxDate::wxDate (const wxDate &dt)
{
    DisplayFormat=dt.DisplayFormat;
    DisplayOptions=dt.DisplayOptions;
    month = dt.month;
    day   = dt.day;
    year  = dt.year;
    mdy_to_julian ();
}

void wxDate::operator = (const wxDate &dt)
{
    DisplayFormat=dt.DisplayFormat;
    DisplayOptions=dt.DisplayOptions;
    month = dt.month;
    day   = dt.day;
    year  = dt.year;
    mdy_to_julian (); // wxUSE_TIMEDATE
}

void wxDate::operator = (const wxString& dat)
{
    DisplayFormat=wxMDY;
    DisplayOptions='\0';
    if (strcmp(dat, "TODAY") == 0 || strcmp(dat, "today") == 0)
    {
        // Sets the current date
        Set();
    }
    else
    {
        char buf[100];
        strcpy(buf, (char *)(const char *)dat);

        char *token = strtok(buf,"/-");
        month = atoi(token);
        day   = atoi(strtok((char *) NULL,"/-"));
        year  = atoi(strtok((char *) NULL," "));
    }

    mdy_to_julian ();
}

//////////////////////////////////////////////////////////////
// Conversion operations
//////////////////////////////////////////////////////////////

#ifndef __SALFORDC__
wxDate::operator wxString( void )
{
    return FormatDate();
}
#endif

//////////////////////////////////////////////////////////////
// Date Arithmetic
//////////////////////////////////////////////////////////////

wxDate wxDate::operator + (long i)
{
    wxDate dp(julian + i);
    return dp;
}

wxDate wxDate::operator + (int i)
{
    wxDate dp(julian + (long)i);
    return dp;
}

wxDate wxDate::operator - (long i)
{
    wxDate dp(julian - i);
    return dp;
}

wxDate wxDate::operator - (int i)
{
    wxDate dp(julian - (long)i);
    return dp;
}

long wxDate::operator - (const wxDate &dt)
{
    return ( julian - dt.julian );
}

wxDate &wxDate::operator += (long i)
{
    julian += i;
    julian_to_mdy();
    return *this;
}

wxDate &wxDate::operator -= (long i)
{
    julian -= i;
    julian_to_mdy();
    return *this;
}

wxDate &wxDate::operator ++()
{
    julian++;
    julian_to_mdy();
    return *this;
}

wxDate &wxDate::operator ++(int)
{
    julian++;
    julian_to_mdy();
    return *this;
}

wxDate &wxDate::operator --()
{
    julian--;
    julian_to_mdy();
    return *this;
}

wxDate &wxDate::operator --(int)
{
    julian--;
    julian_to_mdy();
    return *this;
}

//////////////////////////////////////////////////////////////
// Date comparison
//////////////////////////////////////////////////////////////

bool WXDLLEXPORT operator <  (const wxDate &dt1, const wxDate &dt2)
{
    return ( dt1.julian < dt2.julian );
}

bool WXDLLEXPORT operator <= (const wxDate &dt1, const wxDate &dt2)
{
    return ( (dt1.julian == dt2.julian) || (dt1.julian < dt2.julian) );
}

bool WXDLLEXPORT operator >  (const wxDate &dt1, const wxDate &dt2)
{
    return ( dt1.julian > dt2.julian );
}

bool WXDLLEXPORT operator >= (const wxDate &dt1, const wxDate &dt2)
{
    return ( (dt1.julian == dt2.julian) || (dt1.julian > dt2.julian) );
}

bool WXDLLEXPORT operator == (const wxDate &dt1, const wxDate &dt2)
{
    return ( dt1.julian == dt2.julian );
}

bool WXDLLEXPORT operator != (const wxDate &dt1, const wxDate &dt2)
{
    return ( dt1.julian != dt2.julian );
}

////////////////////////////////////////////////////////////////
// Ostream operations
////////////////////////////////////////////////////////////////

ostream WXDLLEXPORT & operator << (ostream &os, const wxDate &dt)
{
    return os << (const char *) dt.FormatDate();
}

//////////////////////////////////////////////////////////////
// Conversion routines
//////////////////////////////////////////////////////////////

void wxDate::julian_to_wday (void)
{
    day_of_week = (int) ((julian + 2) % 7 + 1);
}

void wxDate::julian_to_mdy ()
{
    long a,b,c,d,e,z,alpha;
    z = julian+1;
    // dealing with Gregorian calendar reform
    if (z < 2299161L)
        a = z;
    else {
        alpha = (long) ((z-1867216.25) / 36524.25);
        a = z + 1 + alpha - alpha/4;
    }
    b = ( a > 1721423 ? a + 1524 : a + 1158 );
    c = (long) ((b - 122.1) / 365.25);
    d = (long) (365.25 * c);
    e = (long) ((b - d) / 30.6001);
    day = (int)(b - d - (long)(30.6001 * e));
    month = (int)((e < 13.5) ? e - 1 : e - 13);
    year = (int)((month > 2.5 ) ? (c - 4716) : c - 4715);
    julian_to_wday ();
}

void wxDate::mdy_to_julian (void)
{
    int a,b=0;
    int work_month=month, work_day=day, work_year=year;
    // correct for negative year
    if (work_year < 0)
        work_year++;
    if (work_month <= 2)
    { work_year--; work_month +=12; }

    // deal with Gregorian calendar
    if (work_year*10000. + work_month*100. + work_day >= 15821015.)
    {
        a = (int)(work_year/100.);
        b = 2 - a + a/4;
    }
    julian = (long) (365.25*work_year) +
        (long) (30.6001 * (work_month+1))  +  work_day + 1720994L + b;
    julian_to_wday ();
}

////////////////////////////////////////////////////////////////
// Format routine
////////////////////////////////////////////////////////////////

wxString wxDate::FormatDate (int type) const
{
    int actualType = type;
    if (actualType == -1)
        actualType = DisplayFormat;

    char buf[40];

    memset( buf, '\0', sizeof(buf) );
    switch ( actualType )
    {
        case wxDAY:
            if ( (day_of_week < 1) || (day_of_week > 7) )
                strcpy(buf, _("invalid day"));
            else
                strncpy( buf, _(dayname[day_of_week-1]),
                        (DisplayOptions & wxDATE_ABBR) ? ABBR_LENGTH : 9);
            return wxString(buf);

        case wxMONTH:
            if ( (month < 1) || (month > 12) )
                strcpy(buf, _("invalid month"));
            else
                strncpy( buf, _(mname[month-1]),
                        (DisplayOptions & wxDATE_ABBR) ? ABBR_LENGTH : 9);
            return wxString(buf);

        case wxFULL:
            if ( (month < 1) || (month > 12) || (day_of_week < 0) ||
                    (day_of_week > 7) )
            {
                strcpy(buf, _("invalid date"));
                return wxString(buf);
            }
            strncpy( buf, _(dayname[day_of_week-1]),
                    (DisplayOptions & wxDATE_ABBR) ? ABBR_LENGTH : 9);
            strcat( buf, ", ");
            strncat( buf, _(mname[month-1]),
                    (DisplayOptions & wxDATE_ABBR) ? ABBR_LENGTH : 9);
            strcat( buf, " ");
            sprintf( buf+strlen(buf), "%d, %d", day, abs(year) );
            if (year < 0)
                strcat(buf,_(" B.C."));
            return wxString(buf);

        case wxEUROPEAN:
            if ( (month < 1) || (month > 12) || (day_of_week < 0) ||
                    (day_of_week > 7) )
            {
                strcpy(buf, _("invalid date"));
                return wxString(buf);
            }
            sprintf(buf,"%d ",  day);
            strncat(buf, _(mname[month-1]),
                    (DisplayOptions & wxDATE_ABBR) ? ABBR_LENGTH : 9);
            sprintf( buf+strlen(buf), " %d", abs(year) );
            if (year < 0)
                strcat(buf, _(" B.C."));
            return wxString(buf);

        case wxMDY:
        default:
            if (day==0 || month==0 || year==0)
                strcpy(buf, _("invalid date"));
            else
                sprintf( buf+strlen(buf), "%1d/%1d/%02d", month, day,
                        (DisplayOptions & wxNO_CENTURY) && (abs(year) > 1899)
                        ? (abs(year) - (abs(year) / 100 * 100))
                        : (abs(year))  );
            return wxString(buf);
    }
    return wxString("");
}

void wxDate::SetFormat( int format )
{
    DisplayFormat = format;
}

int wxDate::SetOption( int option, bool action )
{
    switch ( option )
    {
        case wxNO_CENTURY:
            if ( action )
                DisplayOptions |= wxNO_CENTURY;
            else
            {
                DisplayOptions &= (~wxNO_CENTURY);
            }
            return 1;
        case wxDATE_ABBR:
            if ( action )
                DisplayOptions |= wxDATE_ABBR;
            else
            {
                DisplayOptions &= (~wxDATE_ABBR);
            }
            return 1;
        default:
            return 0;
    }
    return 0;
}

///////////////////////////////////////////////////////////////
//  Miscellaneous Routines
///////////////////////////////////////////////////////////////

long wxDate::GetJulianDate( void ) const
{
    return julian;
}

int wxDate::GetDayOfYear( void ) const
{
    wxDate temp( 1, 1, year );

    return (int) (julian - temp.julian + 1);
}


bool wxDate::IsLeapYear( void ) const
{
    return  ( (year >= 1582) ?
            (year % 4 == 0  &&  year % 100 != 0  ||  year % 400 == 0 ):
            (year % 4 == 0) );
}

// Version 4.0 Extension to Public Interface - CDP

wxDate& wxDate::Set()
{
    //#ifdef __WXMSW__
#if 0
    struct _dosdate_t sDate;
    _dos_getdate(&sDate);

    month = sDate.month;
    day   = sDate.day;
    year  = sDate.year;

    mdy_to_julian();
#else
    time_t now = time((time_t *) NULL);
    struct tm *localTime = localtime(&now);

    month = localTime->tm_mon + 1;
    day = localTime->tm_mday;
    year = localTime->tm_year + 1900;

    mdy_to_julian ();
#endif
    return *this;
}

wxDate& wxDate::Set(
        int  nMonth,
        int  nDay,
        int  nYear)
{
    month = nMonth;
    year  = nYear < 0 ? 9999 : nYear;
    year  = nYear > 9999 ? 0 : nYear;
    day   = nDay < GetDaysInMonth() ? nDay : GetDaysInMonth();

    mdy_to_julian();
    return *this;
}

wxDate &
wxDate::Set(long j)
{
    julian = j;

    julian_to_mdy();
    return *this;
}


int wxDate::GetDaysInMonth()
{
    return GauDays[month-1] + (month==2 && IsLeapYear());
}

int wxDate::GetFirstDayOfMonth() const
{
    return wxDate(month, 1, year).GetDayOfWeek();
}

int wxDate::GetDay() const
{
    return day;
}

int wxDate::GetDayOfWeek() const
{
    return day_of_week;
}

int wxDate::GetYear() const
{
    return year;
}

int wxDate::GetMonth() const
{
    return month;
}

wxDate& wxDate::AddWeeks(int nCount)
{
    Set(julian + (long)nCount*7);
    return *this;
}

wxDate& wxDate::AddMonths(int nCount)
{
    month += nCount;

    if (month < 1) {
        month = 12;
        year--;
    }

    if (month > 12) {
        month = 1;
        year++;
    }
    mdy_to_julian();
    return *this;
}

wxDate& wxDate::AddYears(int nCount)
{
    year += nCount;
    mdy_to_julian();
    return *this;
}

int wxDate::GetWeekOfMonth()
{
    // Abs day includes the days from previous month that fills up
    // the begin. of the week.
    int nAbsDay = day + GetFirstDayOfMonth()-1;
    return (nAbsDay-GetDayOfWeek())/7 + 1;
}

int wxDate::GetWeekOfYear()
{
    wxDate   doTemp(1, 1, year);
    return (int)(((julian - doTemp.julian+1)/7) + 1);
}

wxDate wxDate::GetMonthStart()
{
    return(wxDate(month, 1, year));
}

wxDate wxDate::GetMonthEnd()
{
    return(wxDate(month+1, 1, year)-1);
}

wxDate wxDate::GetYearStart()
{
    return(wxDate(1, 1, year));
}

wxDate wxDate::GetYearEnd()
{
    return(wxDate(1, 1, year+1)-1);
}

wxString wxDate::GetMonthName()
{
    return(FormatDate(wxMONTH));
}

wxString wxDate::GetDayOfWeekName()
{
    return(FormatDate(wxDAY));
}

bool wxDate::IsBetween(const wxDate& first, const wxDate& second) const
{
    return (julian >= first.julian && julian <= second.julian);
}

// This function is from NIHCL
wxDate wxDate::Previous(int dayOfWeek) const
{
    int this_day_Of_Week, desired_day_Of_Week;
    long j;

    //      Set the desired and current day of week to start at 0 (Monday)
    //      and end at 6 (Sunday).

    desired_day_Of_Week = dayOfWeek - 1; // These functions return a value
    this_day_Of_Week    = GetDayOfWeek() - 1;            // from 1-7.  Subtract 1 for 0-6.
    j = julian;

    //      Have to determine how many days difference from current day back to
    //      desired, if any.  Special calculation under the 'if' statement to
    //      effect the wraparound counting from Monday (0) back to Sunday (6).

    if (desired_day_Of_Week > this_day_Of_Week)
        this_day_Of_Week += 7 - desired_day_Of_Week;
    else
        this_day_Of_Week -= desired_day_Of_Week;
    j -= this_day_Of_Week; // Adjust j to set it at the desired day of week.
    return wxDate(j);
}

#endif