/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
/*
* Authors: Jeffrey Stedfast <fejj@helixcode.com>
*
* Copyright 2000 Helix Code, Inc. (www.helixcode.com)
*
* 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, write to the Free Software
* Foundation, Inc., 59 Temple Street #330, Boston, MA 02111-1307, USA.
*
*/
#include "broken-date-parser.h"
/* prototypes for functions dealing with broken date formats */
static GList *datetok (const gchar *date);
static gint get_days_in_month (gint mon, gint year);
static gint get_weekday (gchar *str);
static gint get_month (gchar *str);
static char *tz_months [] = {
"Jan", "Feb", "Mar", "Apr", "May", "Jun",
"Jul", "Aug", "Sep", "Oct", "Nov", "Dec"
};
/*****************************************************************************
* The following functions are here in the case of badly broken date formats *
* *
* -- fejj@helixcode.com *
*****************************************************************************/
typedef struct {
gchar dow[6]; /* day of week (should only need 4 chars) */
gint day;
gint mon; /* 1->12 or 0 if invalid */
gint year;
gint hour;
gint min;
gint sec;
gchar zone[6]; /* time zone */
} date_t;
static
GList *datetok (const gchar *date)
{
GList *tokens = NULL;
gchar *token, *start, *end;
start = (gchar *) date;
while (*start) {
/* find the end of this token */
for (end = start; *end && *end != ' '; end++);
token = g_strndup (start, (end - start));
if (token && *token)
tokens = g_list_append (tokens, token);
else
g_free (token);
if (*end)
start = end + 1;
else
break;
}
return tokens;
}
static gint
get_days_in_month (gint mon, gint year)
{
switch (mon) {
case 1: case 3: case 5: case 7: case 8: case 10: case 12:
return 31;
case 4: case 6: case 9: case 11:
return 30;
case 2:
if ((year % 4 == 0 && year % 100 != 0) || year % 400 == 0)
return 29;
return 28;
default:
return 30;
}
}
static gint
get_weekday (gchar *str)
{
g_return_val_if_fail ((str != NULL), 0);
if (strncmp (str, "Mon", 3) == 0) {
return 1;
} else if (strncmp (str, "Tue", 3) == 0) {
return 2;
} else if (strncmp (str, "Wed", 3) == 0) {
return 3;
} else if (strncmp (str, "Thu", 3) == 0) {
return 4;
} else if (strncmp (str, "Fri", 3) == 0) {
return 5;
} else if (strncmp (str, "Sat", 3) == 0) {
return 6;
} else if (strncmp (str, "Sun", 3) == 0) {
return 7;
}
return 0; /* unknown week day */
}
static gint
get_month (gchar *str)
{
g_return_val_if_fail (str != NULL, 0);
if (strncmp (str, "Jan", 3) == 0) {
return 1;
} else if (strncmp (str, "Feb", 3) == 0) {
return 2;
} else if (strncmp (str, "Mar", 3) == 0) {
return 3;
} else if (strncmp (str, "Apr", 3) == 0) {
return 4;
} else if (strncmp (str, "May", 3) == 0) {
return 5;
} else if (strncmp (str, "Jun", 3) == 0) {
return 6;
} else if (strncmp (str, "Jul", 3) == 0) {
return 7;
} else if (strncmp (str, "Aug", 3) == 0) {
return 8;
} else if (strncmp (str, "Sep", 3) == 0) {
return 9;
} else if (strncmp (str, "Oct", 3) == 0) {
return 10;
} else if (strncmp (str, "Nov", 3) == 0) {
return 11;
} else if (strncmp (str, "Dec", 3) == 0) {
return 12;
}
return 0; /* unknown month */
}
gchar *
parse_broken_date (const gchar *datestr)
{
GList *tokens;
date_t date;
gchar *token, *ptr, *newdatestr;
guint len, i, retval;
gdouble tz = 0.0;
memset ((void*)&date, 0, sizeof (date_t));
g_return_val_if_fail (datestr != NULL, NULL);
tokens = datetok (datestr);
len = g_list_length (tokens);
for (i = 0; i < len; i++) {
token = g_list_nth_data (tokens, i);
if ((retval = get_weekday (token))) {
strncpy (date.dow, datestr, 4);
} else if ((retval = get_month (token))) {
date.mon = retval;
} else if (strlen (token) <= 2) {
/* this could be a 1 or 2 digit day of the month */
for (retval = 1, ptr = token; *ptr; ptr++)
if (*ptr < '0' || *ptr > '9')
retval = 0;
if (retval && atoi (token) <= 31 && !date.day) /* probably should find a better way */
date.day = atoi (token);
else /* fubar'd client using a 2-digit year */
date.year = atoi (token) < 69 ? 2000 + atoi (token) : 1900 + atoi (token);
} else if (strlen (token) == 4) {
/* this could be the year... */
for (retval = 1, ptr = token; *ptr; ptr++)
if (*ptr < '0' || *ptr > '9')
retval = 0;
if (retval)
date.year = atoi (token);
} else if (strchr (token, ':')) {
/* this must be the time: hh:mm:ss */
sscanf (token, "%d:%d:%d", &date.hour, &date.min, &date.sec);
} else if (*token == '-' || *token == '+') {
tz = atoi (token) / 100.0;
}
}
g_list_free (tokens);
/* adjust times based on time zones */
if (tz != 0) {
/* check for time-zone shift */
if (tz > 0) {
/* correct for positive hours off of UCT */
date.hour -= (tz / 100);
tz = (gint)tz % 100;
if (tz > 0) /* correct for positive minutes off of UCT */
date.min -= (gint)(((gdouble) tz / 100.0) * 60.0);
} else {
if (tz < 0) {
/* correct for negative hours off of UCT */
tz = -tz;
date.hour += (tz / 100);
tz = -((gint)tz % 100);
if (tz < 0)
date.min -= (gint)(((gdouble) tz / 100.0) * 60.0);
}
}
/* adjust seconds to proper range */
if (date.sec > 59) {
date.min += (date.sec / 60);
date.sec = (date.sec % 60);
}
/* adjust minutes to proper range */
if (date.min > 59) {
date.hour += (date.min / 60);
date.min = (date.min % 60);
} else {
if (date.min < 0) {
date.min = -date.min;
date.hour -= (date.min / 60) - 1;
date.min = 60 - (date.min % 60);
}
}
/* adjust hours to the proper randge */
if (date.hour > 23) {
date.day += (date.hour / 24);
date.hour -= (date.hour % 24);
} else {
if (date.hour < 0) {
date.hour = -date.hour;
date.day -= (date.hour / 24) - 1;
date.hour = 24 - (date.hour % 60);
}
}
/* adjust days to the proper range */
while (date.day > get_days_in_month (date.mon, date.year)) {
date.day -= get_days_in_month (date.mon, date.year);
date.mon++;
if (date.mon > 12) {
date.year += (date.mon / 12);
date.mon = (date.mon % 12);
if (date.mon == 0) {
/* month sanity check */
date.mon = 12;
date.year -= 1;
}
}
}
while (date.day < 1) {
date.day += get_days_in_month (date.mon, date.year);
date.mon--;
if (date.mon < 1) {
date.mon = -date.mon;
date.year -= (date.mon / 12) - 1;
date.mon = 12 - (date.mon % 12);
}
}
/* adjust months to the proper range */
if (date.mon > 12) {
date.year += (date.mon / 12);
date.mon = (date.mon % 12);
if (date.mon == 0) {
/* month sanity check */
date.mon = 12;
date.year -= 1;
}
} else {
if (date.mon < 1) {
date.mon = -date.mon;
date.year -= (date.mon / 12) - 1;
date.mon = 12 - (date.mon % 12);
}
}
}
/* now lets print this date into a string with the correct format */
newdatestr = g_strdup_printf ("%s, %d %s %d %s%d:%s%d:%s%d -0000",
date.dow, date.day, tz_months[date.mon-1],
date.year,
date.hour > 10 ? "" : "0", date.hour,
date.min > 10 ? "" : "0", date.min,
date.sec > 10 ? "" : "0", date.sec);
return newdatestr;
}
/*****************************************************************************
* This ends the code for the broken date parser... *
* *
* -- fejj@helixcode.com *
*****************************************************************************/
