/* GStreamer

 * Copyright (C) 2010 Thiago Santos <thiago.sousa.santos@collabora.co.uk>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,

 * Boston, MA 02110-1301, USA.

 */

#ifdef HAVE_CONFIG_H

#include "config.h"

#endif

#include "gst_private.h"

#include "glib-compat-private.h"

#include "gstdatetime.h"

#include "gstvalue.h"

#include <glib.h>

#include <math.h>

#include <stdio.h>

/**

 * SECTION:gstdatetime

 * @title: GstDateTime

 * @short_description: A date, time and timezone structure

 *

 * Struct to store date, time and timezone information altogether.

 * #GstDateTime is refcounted and immutable.

 *

 * Date information is handled using the proleptic Gregorian calendar.

 *

 * Provides basic creation functions and accessor functions to its fields.

 */

typedef enum

{

  GST_DATE_TIME_FIELDS_INVALID = 0,

  GST_DATE_TIME_FIELDS_Y,       /* have year                */

  GST_DATE_TIME_FIELDS_YM,      /* have year and month      */

  GST_DATE_TIME_FIELDS_YMD,     /* have year, month and day */

  GST_DATE_TIME_FIELDS_YMD_HM,

  GST_DATE_TIME_FIELDS_YMD_HMS

      /* Note: if we ever add more granularity here, e.g. for microsecs,

       * the compare function will need updating */

} GstDateTimeFields;

struct _GstDateTime

{

  GstMiniObject mini_object;

  GDateTime *datetime;

  GstDateTimeFields fields;

};

GType _gst_date_time_type = 0;

GST_DEFINE_MINI_OBJECT_TYPE (GstDateTime, gst_date_time);

static void gst_date_time_free (GstDateTime * datetime);

/**

 * gst_date_time_new_from_g_date_time:

 * @dt: (transfer full): the #GDateTime. The new #GstDateTime takes ownership.

 *

 * Creates a new #GstDateTime from a #GDateTime object.

 *

 * Free-function: gst_date_time_unref

 *

 * Returns: (transfer full) (nullable): a newly created #GstDateTime,

 * or %NULL on error

 */

GstDateTime *

gst_date_time_new_from_g_date_time (GDateTime * dt)

{

  GstDateTime *gst_dt;

  if (!dt)

    return NULL;

  gst_dt = g_slice_new (GstDateTime);

  gst_mini_object_init (GST_MINI_OBJECT_CAST (gst_dt), 0, GST_TYPE_DATE_TIME,

      NULL, NULL, (GstMiniObjectFreeFunction) gst_date_time_free);

  gst_dt->datetime = dt;

  gst_dt->fields = GST_DATE_TIME_FIELDS_YMD_HMS;

  return gst_dt;

}

/**

 * gst_date_time_to_g_date_time:

 * @datetime: GstDateTime.

 *

 * Creates a new #GDateTime from a fully defined #GstDateTime object.

 *

 * Free-function: g_date_time_unref

 *

 * Returns: (transfer full) (nullable): a newly created #GDateTime, or

 * %NULL on error

 */

GDateTime *

gst_date_time_to_g_date_time (GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, NULL);

  if (datetime->fields != GST_DATE_TIME_FIELDS_YMD_HMS)

    return NULL;

  return g_date_time_add (datetime->datetime, 0);

}

/**

 * gst_date_time_has_year:

 * @datetime: a #GstDateTime

 *

 * Returns: %TRUE if @datetime's year field is set (which should always

 *     be the case), otherwise %FALSE

 */

gboolean

gst_date_time_has_year (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, FALSE);

  return (datetime->fields >= GST_DATE_TIME_FIELDS_Y);

}

/**

 * gst_date_time_has_month:

 * @datetime: a #GstDateTime

 *

 * Returns: %TRUE if @datetime's month field is set, otherwise %FALSE

 */

gboolean

gst_date_time_has_month (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, FALSE);

  return (datetime->fields >= GST_DATE_TIME_FIELDS_YM);

}

/**

 * gst_date_time_has_day:

 * @datetime: a #GstDateTime

 *

 * Returns: %TRUE if @datetime's day field is set, otherwise %FALSE

 */

gboolean

gst_date_time_has_day (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, FALSE);

  return (datetime->fields >= GST_DATE_TIME_FIELDS_YMD);

}

/**

 * gst_date_time_has_time:

 * @datetime: a #GstDateTime

 *

 * Returns: %TRUE if @datetime's hour and minute fields are set,

 *     otherwise %FALSE

 */

gboolean

gst_date_time_has_time (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, FALSE);

  return (datetime->fields >= GST_DATE_TIME_FIELDS_YMD_HM);

}

/**

 * gst_date_time_has_second:

 * @datetime: a #GstDateTime

 *

 * Returns: %TRUE if @datetime's second field is set, otherwise %FALSE

 */

gboolean

gst_date_time_has_second (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, FALSE);

  return (datetime->fields >= GST_DATE_TIME_FIELDS_YMD_HMS);

}

/**

 * gst_date_time_get_year:

 * @datetime: a #GstDateTime

 *

 * Returns the year of this #GstDateTime

 * Call gst_date_time_has_year before, to avoid warnings.

 *

 * Return value: The year of this #GstDateTime

 */

gint

gst_date_time_get_year (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0);

  return g_date_time_get_year (datetime->datetime);

}

/**

 * gst_date_time_get_month:

 * @datetime: a #GstDateTime

 *

 * Returns the month of this #GstDateTime. January is 1, February is 2, etc..

 * Call gst_date_time_has_month before, to avoid warnings.

 *

 * Return value: The month of this #GstDateTime

 */

gint

gst_date_time_get_month (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0);

  g_return_val_if_fail (gst_date_time_has_month (datetime), 0);

  return g_date_time_get_month (datetime->datetime);

}

/**

 * gst_date_time_get_day:

 * @datetime: a #GstDateTime

 *

 * Returns the day of the month of this #GstDateTime.

 * Call gst_date_time_has_day before, to avoid warnings.

 *

 * Return value: The day of this #GstDateTime

 */

gint

gst_date_time_get_day (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0);

  g_return_val_if_fail (gst_date_time_has_day (datetime), 0);

  return g_date_time_get_day_of_month (datetime->datetime);

}

/**

 * gst_date_time_get_hour:

 * @datetime: a #GstDateTime

 *

 * Retrieves the hour of the day represented by @datetime in the gregorian

 * calendar. The return is in the range of 0 to 23.

 * Call gst_date_time_has_haur before, to avoid warnings.

 *

 * Return value: the hour of the day

 */

gint

gst_date_time_get_hour (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0);

  g_return_val_if_fail (gst_date_time_has_time (datetime), 0);

  return g_date_time_get_hour (datetime->datetime);

}

/**

 * gst_date_time_get_minute:

 * @datetime: a #GstDateTime

 *

 * Retrieves the minute of the hour represented by @datetime in the gregorian

 * calendar.

 * Call gst_date_time_has_minute before, to avoid warnings.

 *

 * Return value: the minute of the hour

 */

gint

gst_date_time_get_minute (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0);

  g_return_val_if_fail (gst_date_time_has_time (datetime), 0);

  return g_date_time_get_minute (datetime->datetime);

}

/**

 * gst_date_time_get_second:

 * @datetime: a #GstDateTime

 *

 * Retrieves the second of the minute represented by @datetime in the gregorian

 * calendar.

 * Call gst_date_time_has_second before, to avoid warnings.

 *

 * Return value: the second represented by @datetime

 */

gint

gst_date_time_get_second (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0);

  g_return_val_if_fail (gst_date_time_has_second (datetime), 0);

  return g_date_time_get_second (datetime->datetime);

}

/**

 * gst_date_time_get_microsecond:

 * @datetime: a #GstDateTime

 *

 * Retrieves the fractional part of the seconds in microseconds represented by

 * @datetime in the gregorian calendar.

 *

 * Return value: the microsecond of the second

 */

gint

gst_date_time_get_microsecond (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0);

  g_return_val_if_fail (gst_date_time_has_second (datetime), 0);

  return g_date_time_get_microsecond (datetime->datetime);

}

/**

 * gst_date_time_get_time_zone_offset:

 * @datetime: a #GstDateTime

 *

 * Retrieves the offset from UTC in hours that the timezone specified

 * by @datetime represents. Timezones ahead (to the east) of UTC have positive

 * values, timezones before (to the west) of UTC have negative values.

 * If @datetime represents UTC time, then the offset is zero.

 *

 * Return value: the offset from UTC in hours

 */

gfloat

gst_date_time_get_time_zone_offset (const GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, 0.0);

  g_return_val_if_fail (gst_date_time_has_time (datetime), 0.0);

  return (g_date_time_get_utc_offset (datetime->datetime) /

      G_USEC_PER_SEC) / 3600.0;

}

/**

 * gst_date_time_new_y:

 * @year: the gregorian year

 *

 * Creates a new #GstDateTime using the date and times in the gregorian calendar

 * in the local timezone.

 *

 * @year should be from 1 to 9999.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full): the newly created #GstDateTime

 */

GstDateTime *

gst_date_time_new_y (gint year)

{

  return gst_date_time_new (0.0, year, -1, -1, -1, -1, -1);

}

/**

 * gst_date_time_new_ym:

 * @year: the gregorian year

 * @month: the gregorian month

 *

 * Creates a new #GstDateTime using the date and times in the gregorian calendar

 * in the local timezone.

 *

 * @year should be from 1 to 9999, @month should be from 1 to 12.

 *

 * If value is -1 then all over value will be ignored. For example

 * if @month == -1, then #GstDateTime will created only for @year.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full): the newly created #GstDateTime

 */

GstDateTime *

gst_date_time_new_ym (gint year, gint month)

{

  return gst_date_time_new (0.0, year, month, -1, -1, -1, -1);

}

/**

 * gst_date_time_new_ymd:

 * @year: the gregorian year

 * @month: the gregorian month

 * @day: the day of the gregorian month

 *

 * Creates a new #GstDateTime using the date and times in the gregorian calendar

 * in the local timezone.

 *

 * @year should be from 1 to 9999, @month should be from 1 to 12, @day from

 * 1 to 31.

 *

 * If value is -1 then all over value will be ignored. For example

 * if @month == -1, then #GstDateTime will created only for @year. If

 * @day == -1, then #GstDateTime will created for @year and @month and

 * so on.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full): the newly created #GstDateTime

 */

GstDateTime *

gst_date_time_new_ymd (gint year, gint month, gint day)

{

  return gst_date_time_new (0.0, year, month, day, -1, -1, -1);

}

/**

 * gst_date_time_new_from_unix_epoch_local_time:

 * @secs: seconds from the Unix epoch

 *

 * Creates a new #GstDateTime using the time since Jan 1, 1970 specified by

 * @secs. The #GstDateTime is in the local timezone.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full): the newly created #GstDateTime

 */

GstDateTime *

gst_date_time_new_from_unix_epoch_local_time (gint64 secs)

{

  GDateTime *datetime;

  datetime = g_date_time_new_from_unix_local (secs);

  return gst_date_time_new_from_g_date_time (datetime);

}

/**

 * gst_date_time_new_from_unix_epoch_utc:

 * @secs: seconds from the Unix epoch

 *

 * Creates a new #GstDateTime using the time since Jan 1, 1970 specified by

 * @secs. The #GstDateTime is in the UTC timezone.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full): the newly created #GstDateTime

 */

GstDateTime *

gst_date_time_new_from_unix_epoch_utc (gint64 secs)

{

  GstDateTime *datetime;

  datetime =

      gst_date_time_new_from_g_date_time (g_date_time_new_from_unix_utc (secs));

  return datetime;

}

static GstDateTimeFields

gst_date_time_check_fields (gint * year, gint * month, gint * day,

    gint * hour, gint * minute, gdouble * seconds)

{

  if (*month == -1) {

    *month = *day = 1;

    *hour = *minute = *seconds = 0;

    return GST_DATE_TIME_FIELDS_Y;

  } else if (*day == -1) {

    *day = 1;

    *hour = *minute = *seconds = 0;

    return GST_DATE_TIME_FIELDS_YM;

  } else if (*hour == -1) {

    *hour = *minute = *seconds = 0;

    return GST_DATE_TIME_FIELDS_YMD;

  } else if (*seconds == -1) {

    *seconds = 0;

    return GST_DATE_TIME_FIELDS_YMD_HM;

  } else

    return GST_DATE_TIME_FIELDS_YMD_HMS;

}

/**

 * gst_date_time_new_local_time:

 * @year: the gregorian year

 * @month: the gregorian month, or -1

 * @day: the day of the gregorian month, or -1

 * @hour: the hour of the day, or -1

 * @minute: the minute of the hour, or -1

 * @seconds: the second of the minute, or -1

 *

 * Creates a new #GstDateTime using the date and times in the gregorian calendar

 * in the local timezone.

 *

 * @year should be from 1 to 9999, @month should be from 1 to 12, @day from

 * 1 to 31, @hour from 0 to 23, @minutes and @seconds from 0 to 59.

 *

 * If @month is -1, then the #GstDateTime created will only contain @year,

 * and all other fields will be considered not set.

 *

 * If @day is -1, then the #GstDateTime created will only contain @year and

 * @month and all other fields will be considered not set.

 *

 * If @hour is -1, then the #GstDateTime created will only contain @year and

 * @month and @day, and the time fields will be considered not set. In this

 * case @minute and @seconds should also be -1.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full) (nullable): the newly created #GstDateTime

 */

GstDateTime *

gst_date_time_new_local_time (gint year, gint month, gint day, gint hour,

    gint minute, gdouble seconds)

{

  GstDateTimeFields fields;

  GstDateTime *datetime;

  g_return_val_if_fail (year > 0 && year <= 9999, NULL);

  g_return_val_if_fail ((month > 0 && month <= 12) || month == -1, NULL);

  g_return_val_if_fail ((day > 0 && day <= 31) || day == -1, NULL);

  g_return_val_if_fail ((hour >= 0 && hour < 24) || hour == -1, NULL);

  g_return_val_if_fail ((minute >= 0 && minute < 60) || minute == -1, NULL);

  g_return_val_if_fail ((seconds >= 0 && seconds < 60) || seconds == -1, NULL);

  fields = gst_date_time_check_fields (&year, &month, &day,

      &hour, &minute, &seconds);

  datetime = gst_date_time_new_from_g_date_time (g_date_time_new_local (year,

          month, day, hour, minute, seconds));

  datetime->fields = fields;

  return datetime;

}

/**

 * gst_date_time_new_now_local_time:

 *

 * Creates a new #GstDateTime representing the current date and time.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full): the newly created #GstDateTime which should

 *     be freed with gst_date_time_unref().

 */

GstDateTime *

gst_date_time_new_now_local_time (void)

{

  return gst_date_time_new_from_g_date_time (g_date_time_new_now_local ());

}

/**

 * gst_date_time_new_now_utc:

 *

 * Creates a new #GstDateTime that represents the current instant at Universal

 * coordinated time.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full): the newly created #GstDateTime which should

 *   be freed with gst_date_time_unref().

 */

GstDateTime *

gst_date_time_new_now_utc (void)

{

  return gst_date_time_new_from_g_date_time (g_date_time_new_now_utc ());

}

gint

__gst_date_time_compare (const GstDateTime * dt1, const GstDateTime * dt2)

{

  gint64 diff;

  /* we assume here that GST_DATE_TIME_FIELDS_YMD_HMS is the highest

   * resolution, and ignore microsecond differences on purpose for now */

  if (dt1->fields != dt2->fields)

    return GST_VALUE_UNORDERED;

  /* This will round down to nearest second, which is what we want. We're

   * not comparing microseconds on purpose here, since we're not

   * serialising them when doing new_utc_now() + to_string() */

  diff =

      g_date_time_to_unix (dt1->datetime) - g_date_time_to_unix (dt2->datetime);

  if (diff < 0)

    return GST_VALUE_LESS_THAN;

  else if (diff > 0)

    return GST_VALUE_GREATER_THAN;

  else

    return GST_VALUE_EQUAL;

}

/**

 * gst_date_time_new:

 * @tzoffset: Offset from UTC in hours.

 * @year: the gregorian year

 * @month: the gregorian month

 * @day: the day of the gregorian month

 * @hour: the hour of the day

 * @minute: the minute of the hour

 * @seconds: the second of the minute

 *

 * Creates a new #GstDateTime using the date and times in the gregorian calendar

 * in the supplied timezone.

 *

 * @year should be from 1 to 9999, @month should be from 1 to 12, @day from

 * 1 to 31, @hour from 0 to 23, @minutes and @seconds from 0 to 59.

 *

 * Note that @tzoffset is a float and was chosen so for being able to handle

 * some fractional timezones, while it still keeps the readability of

 * representing it in hours for most timezones.

 *

 * If value is -1 then all over value will be ignored. For example

 * if @month == -1, then #GstDateTime will created only for @year. If

 * @day == -1, then #GstDateTime will created for @year and @month and

 * so on.

 *

 * Free-function: gst_date_time_unref

 *

 * Return value: (transfer full) (nullable): the newly created #GstDateTime

 */

GstDateTime *

gst_date_time_new (gfloat tzoffset, gint year, gint month, gint day, gint hour,

    gint minute, gdouble seconds)

{

  GstDateTimeFields fields;

  gchar buf[6];

  GTimeZone *tz;

  GDateTime *dt;

  GstDateTime *datetime;

  gint tzhour, tzminute;

  g_return_val_if_fail (year > 0 && year <= 9999, NULL);

  g_return_val_if_fail ((month > 0 && month <= 12) || month == -1, NULL);

  g_return_val_if_fail ((day > 0 && day <= 31) || day == -1, NULL);

  g_return_val_if_fail ((hour >= 0 && hour < 24) || hour == -1, NULL);

  g_return_val_if_fail ((minute >= 0 && minute < 60) || minute == -1, NULL);

  g_return_val_if_fail ((seconds >= 0 && seconds < 60) || seconds == -1, NULL);

  g_return_val_if_fail (tzoffset >= -12.0 && tzoffset <= 12.0, NULL);

  g_return_val_if_fail ((hour >= 0 && minute >= 0) ||

      (hour == -1 && minute == -1 && seconds == -1 && tzoffset == 0.0), NULL);

  tzhour = (gint) ABS (tzoffset);

  tzminute = (gint) ((ABS (tzoffset) - tzhour) * 60);

  g_snprintf (buf, 6, "%c%02d%02d", tzoffset >= 0 ? '+' : '-', tzhour,

      tzminute);

  tz = g_time_zone_new (buf);

  fields = gst_date_time_check_fields (&year, &month, &day,

      &hour, &minute, &seconds);

  dt = g_date_time_new (tz, year, month, day, hour, minute, seconds);

  g_time_zone_unref (tz);

  datetime = gst_date_time_new_from_g_date_time (dt);

  datetime->fields = fields;

  return datetime;

}

gchar *

__gst_date_time_serialize (GstDateTime * datetime, gboolean serialize_usecs)

{

  GString *s;

  gfloat gmt_offset;

  guint msecs;

  /* we always have at least the year */

  s = g_string_new (NULL);

  g_string_append_printf (s, "%04u", gst_date_time_get_year (datetime));

  if (datetime->fields == GST_DATE_TIME_FIELDS_Y)

    goto done;

  /* add month */

  g_string_append_printf (s, "-%02u", gst_date_time_get_month (datetime));

  if (datetime->fields == GST_DATE_TIME_FIELDS_YM)

    goto done;

  /* add day of month */

  g_string_append_printf (s, "-%02u", gst_date_time_get_day (datetime));

  if (datetime->fields == GST_DATE_TIME_FIELDS_YMD)

    goto done;

  /* add time */

  g_string_append_printf (s, "T%02u:%02u", gst_date_time_get_hour (datetime),

      gst_date_time_get_minute (datetime));

  if (datetime->fields == GST_DATE_TIME_FIELDS_YMD_HM)

    goto add_timezone;

  /* add seconds */

  g_string_append_printf (s, ":%02u", gst_date_time_get_second (datetime));

  /* add microseconds */

  if (serialize_usecs) {

    msecs = gst_date_time_get_microsecond (datetime);

    if (msecs != 0) {

      g_string_append_printf (s, ".%06u", msecs);

      /* trim trailing 0s */

      while (s->str[s->len - 1] == '0')

        g_string_truncate (s, s->len - 1);

    }

  }

  /* add timezone */

add_timezone:

  gmt_offset = gst_date_time_get_time_zone_offset (datetime);

  if (gmt_offset == 0) {

    g_string_append_c (s, 'Z');

  } else {

    guint tzhour, tzminute;

    tzhour = (guint) ABS (gmt_offset);

    tzminute = (guint) ((ABS (gmt_offset) - tzhour) * 60);

    g_string_append_c (s, (gmt_offset >= 0) ? '+' : '-');

    g_string_append_printf (s, "%02u%02u", tzhour, tzminute);

  }

done:

  return g_string_free (s, FALSE);

}

/**

 * gst_date_time_to_iso8601_string:

 * @datetime: GstDateTime.

 *

 * Create a minimal string compatible with ISO-8601. Possible output formats

 * are (for example): 2012, 2012-06, 2012-06-23, 2012-06-23T23:30Z,

 * 2012-06-23T23:30+0100, 2012-06-23T23:30:59Z, 2012-06-23T23:30:59+0100

 *

 * Returns: (nullable): a newly allocated string formatted according

 *     to ISO 8601 and only including the datetime fields that are

 *     valid, or %NULL in case there was an error. The string should

 *     be freed with g_free().

 */

gchar *

gst_date_time_to_iso8601_string (GstDateTime * datetime)

{

  g_return_val_if_fail (datetime != NULL, NULL);

  if (datetime->fields == GST_DATE_TIME_FIELDS_INVALID)

    return NULL;

  return __gst_date_time_serialize (datetime, FALSE);

}

/**

 * gst_date_time_new_from_iso8601_string:

 * @string: ISO 8601-formatted datetime string.

 *

 * Tries to parse common variants of ISO-8601 datetime strings into a

 * #GstDateTime. Possible input formats are (for example):

 * 2012-06-30T22:46:43Z, 2012, 2012-06, 2012-06-30, 2012-06-30T22:46:43-0430,

 * 2012-06-30T22:46Z, 2012-06-30T22:46-0430, 2012-06-30 22:46,

 * 2012-06-30 22:46:43, 2012-06-00, 2012-00-00, 2012-00-30, 22:46:43Z, 22:46Z,

 * 22:46:43-0430, 22:46-0430, 22:46:30, 22:46

 * If no date is provided, it is assumed to be "today" in the timezone

 * provided (if any), otherwise UTC.

 *

 * Free-function: gst_date_time_unref

 *

 * Returns: (transfer full) (nullable): a newly created #GstDateTime,

 * or %NULL on error

 */

GstDateTime *

gst_date_time_new_from_iso8601_string (const gchar * string)

{

  gint year = -1, month = -1, day = -1, hour = -1, minute = -1;

  gint gmt_offset_hour = -99, gmt_offset_min = -99;

  gdouble second = -1.0;

  gfloat tzoffset = 0.0;

  guint64 usecs;

  gint len, ret;

  g_return_val_if_fail (string != NULL, NULL);

  GST_DEBUG ("Parsing '%s' into a datetime", string);

  len = strlen (string);

  /* The input string is expected to start either with a year (4 digits) or

   * with an hour (2 digits). Hour must be followed by minute. In any case,

   * the string must be at least 4 characters long and start with 2 digits */

  if (len < 4 || !g_ascii_isdigit (string[0]) || !g_ascii_isdigit (string[1]))

    return NULL;

  if (g_ascii_isdigit (string[2]) && g_ascii_isdigit (string[3])) {

    ret = sscanf (string, "%04d-%02d-%02d", &year, &month, &day;;

    if (ret == 0)

      return NULL;

    if (ret == 3 && day <= 0) {

      ret = 2;

      day = -1;

    }

    if (ret >= 2 && month <= 0) {

      ret = 1;

      month = day = -1;

    }

    if (ret >= 1 && (year <= 0 || year > 9999 || month > 12 || day > 31))

      return NULL;

    else if (ret >= 1 && len < 16)

      /* YMD is 10 chars. XMD + HM will be 16 chars. if it is less,

       * it make no sense to continue. We will stay with YMD. */

      goto ymd;

    string += 10;

    /* Exit if there is no expeceted value on this stage */

    if (!(*string == 'T' || *string == '-' || *string == ' '))

      goto ymd;

    string += 1;

  }

  /* if hour or minute fails, then we will use only ymd. */

  hour = g_ascii_strtoull (string, (gchar **) & string, 10);

  if (hour > 24 || *string != ':')

    goto ymd;

  /* minute */

  minute = g_ascii_strtoull (string + 1, (gchar **) & string, 10);

  if (minute > 59)

    goto ymd;

  /* second */

  if (*string == ':') {

    second = g_ascii_strtoull (string + 1, (gchar **) & string, 10);

    /* if we fail here, we still can reuse hour and minute. We

     * will still attempt to parse any timezone information */

    if (second > 59) {

      second = -1.0;

    } else {

      /* microseconds */

      if (*string == '.' || *string == ',') {

        const gchar *usec_start = string + 1;

        guint digits;

        usecs = g_ascii_strtoull (string + 1, (gchar **) & string, 10);

        if (usecs != G_MAXUINT64 && string > usec_start) {

          digits = (guint) (string - usec_start);

          second += (gdouble) usecs / pow (10.0, digits);

        }

      }

    }

  }

  if (*string == 'Z')

    goto ymd_hms;

  else {

    /* reuse some code from gst-plugins-base/gst-libs/gst/tag/gstxmptag.c */

    gint gmt_offset = -1;

    gchar *plus_pos = NULL;

    gchar *neg_pos = NULL;

    gchar *pos = NULL;

    GST_LOG ("Checking for timezone information");

    /* check if there is timezone info */

    plus_pos = strrchr (string, '+');

    neg_pos = strrchr (string, '-');

    if (plus_pos)

      pos = plus_pos + 1;

    else if (neg_pos)

      pos = neg_pos + 1;

    if (pos && strlen (pos) >= 3) {

      gint ret_tz;

      if (pos[2] == ':')

        ret_tz = sscanf (pos, "%d:%d", &gmt_offset_hour, &gmt_offset_min);

      else

        ret_tz = sscanf (pos, "%02d%02d", &gmt_offset_hour, &gmt_offset_min);

      GST_DEBUG ("Parsing timezone: %s", pos);

      if (ret_tz == 2) {

        if (neg_pos != NULL && neg_pos + 1 == pos) {

          gmt_offset_hour *= -1;

          gmt_offset_min *= -1;