gnc-gdate-utils.c

/*
 * gnc-gdate-utils.c -- utility functions for manipulating
 *              GDate data structures from GLib
 * Copyright (C) 2005 David Hampton <hampton@employees.org>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation; either version 2 of
 * the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, contact:
 *
 * Free Software Foundation           Voice:  +1-617-542-5942
 * 51 Franklin Street, Fifth Floor    Fax:    +1-617-542-2652
 * Boston, MA  02110-1301,  USA       gnu@gnu.org
 */

#include "config.h"
#include <glib.h>
#include <time.h>

#include "gnc-gdate-utils.h"


gboolean
gnc_gdate_equal(gconstpointer gda, gconstpointer gdb)
{
  return (g_date_compare( (GDate*)gda, (GDate*)gdb ) == 0 ? TRUE : FALSE);
}

guint
gnc_gdate_hash( gconstpointer gd )
{
  gint val = (g_date_get_year( (GDate*)gd ) * 10000)
    + (g_date_get_month( (GDate*)gd ) * 100)
    + g_date_get_day( (GDate*)gd );
  return g_int_hash( &val );
}


time_t
gnc_timet_get_day_start_gdate (GDate *date)
{
  struct tm stm;
  time_t secs;

  /* First convert to a 'struct tm' */
  g_date_to_struct_tm(date, &stm);

  /* Then convert to number of seconds */
  secs = mktime (&stm);
  return secs;
}

time_t
gnc_timet_get_day_end_gdate (GDate *date)
{
  struct tm stm;
  time_t secs;

  /* First convert to a 'struct tm' */
  g_date_to_struct_tm(date, &stm);

  /* Force to th last second of the day */
  stm.tm_hour = 23;
  stm.tm_min = 59;
  stm.tm_sec = 59;
  stm.tm_isdst = -1;

  /* Then convert to number of seconds */
  secs = mktime (&stm);
  return secs;
}


void
gnc_gdate_set_month_start (GDate *date)
{
  g_date_set_day(date, 1);
}


void
gnc_gdate_set_month_end (GDate *date)
{
  /* First set the start of next month. */
  g_date_set_day(date, 1);
  g_date_add_months(date, 1);

  /* Then back up one day */
  g_date_subtract_days(date, 1);
}


void
gnc_gdate_set_prev_month_start (GDate *date)
{
  g_date_set_day(date, 1);
  g_date_subtract_months(date, 1);
}


void
gnc_gdate_set_prev_month_end (GDate *date)
{
  /* This will correctly handle the varying month lengths */
  g_date_set_day(date, 1);
  g_date_subtract_days(date, 1);
}

/* ========== */

void
gnc_gdate_set_quarter_start (GDate *date)
{
  gint months;

  /* Set the date to the first day of the specified month. */
  g_date_set_day(date, 1);

  /* Back up 0-2 months */ 
  months = (g_date_get_month(date) - G_DATE_JANUARY) % 3;
  g_date_subtract_months(date, months);
}


void
gnc_gdate_set_quarter_end (GDate *date)
{
  gint months;

  /* Set the date to the first day of the specified month. */
  g_date_set_day(date, 1);

  /* Add 1-3 months to get the first day of the next quarter.*/
  months = (g_date_get_month(date) - G_DATE_JANUARY) % 3;
  g_date_add_months(date, 3 - months);

  /* Now back up one day */
  g_date_subtract_days(date, 1);
}


void
gnc_gdate_set_prev_quarter_start (GDate *date)
{
  gnc_gdate_set_quarter_start(date);
  g_date_subtract_months(date, 3);
}


void
gnc_gdate_set_prev_quarter_end (GDate *date)
{
  gnc_gdate_set_quarter_end(date);
  g_date_subtract_months(date, 3);
}

/* ========== */

void
gnc_gdate_set_year_start (GDate *date)
{
  g_date_set_month(date, G_DATE_JANUARY);
  g_date_set_day(date, 1);
}


void
gnc_gdate_set_year_end (GDate *date)
{
  g_date_set_month(date, G_DATE_DECEMBER);
  g_date_set_day(date, 31);
}


void
gnc_gdate_set_prev_year_start (GDate *date)
{
  gnc_gdate_set_year_start(date);
  g_date_subtract_years(date, 1);
}


void
gnc_gdate_set_prev_year_end (GDate *date)
{
  gnc_gdate_set_year_end(date);
  g_date_subtract_years(date, 1);
}

/* ========== */

void
gnc_gdate_set_fiscal_year_start (GDate *date,
                                const GDate *fy_end)
{
  GDate temp;
  gboolean new_fy;

  g_return_if_fail(date);
  g_return_if_fail(fy_end);

  /* Compute the FY end that occurred this CY */
  temp = *fy_end;
  g_date_set_year(&temp, g_date_get_year(date));

  /* Has it already passed? */
  new_fy = (g_date_compare(date, &temp) > 0);

  /* Set start date */
  *date = temp;
  g_date_add_days(date, 1);
  if (!new_fy)
    g_date_subtract_years(date, 1);
}

void
gnc_gdate_set_fiscal_year_end (GDate *date,
                              const GDate *fy_end)
{
  GDate temp;
  gboolean new_fy;

  g_return_if_fail(date);
  g_return_if_fail(fy_end);

  /* Compute the FY end that occurred this CY */
  temp = *fy_end;
  g_date_set_year(&temp, g_date_get_year(date));

  /* Has it already passed? */
  new_fy = (g_date_compare(date, &temp) > 0);

  /* Set end date */
  *date = temp;
  if (new_fy)
    g_date_add_years(date, 1);
}

void
gnc_gdate_set_prev_fiscal_year_start (GDate *date,
                                     const GDate *fy_end)
{
  g_return_if_fail(date);
  g_return_if_fail(fy_end);

  gnc_gdate_set_fiscal_year_start(date, fy_end);
  g_date_subtract_years(date, 1);
}

void
gnc_gdate_set_prev_fiscal_year_end (GDate *date,
                                   const GDate *fy_end)
{
  g_return_if_fail(date);
  g_return_if_fail(fy_end);

  gnc_gdate_set_fiscal_year_end(date, fy_end);
  g_date_subtract_years(date, 1);
}

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