/*
 *  call-seq:
 *     time.strftime( string ) => string
 *  
 *  Formats <i>time</i> according to the directives in the given format
 *  string. Any text not listed as a directive will be passed through
 *  to the output string.
 *
 *  Format meaning:
 *    %a - The abbreviated weekday name (``Sun'')
 *    %A - The  full  weekday  name (``Sunday'')
 *    %b - The abbreviated month name (``Jan'')
 *    %B - The  full  month  name (``January'')
 *    %c - The preferred local date and time representation
 *    %d - Day of the month (01..31)
 *    %H - Hour of the day, 24-hour clock (00..23)
 *    %I - Hour of the day, 12-hour clock (01..12)
 *    %j - Day of the year (001..366)
 *    %m - Month of the year (01..12)
 *    %M - Minute of the hour (00..59)
 *    %p - Meridian indicator (``AM''  or  ``PM'')
 *    %S - Second of the minute (00..60)
 *    %U - Week  number  of the current year,
 *            starting with the first Sunday as the first
 *            day of the first week (00..53)
 *    %W - Week  number  of the current year,
 *            starting with the first Monday as the first
 *            day of the first week (00..53)
 *    %w - Day of the week (Sunday is 0, 0..6)
 *    %x - Preferred representation for the date alone, no time
 *    %X - Preferred representation for the time alone, no date
 *    %y - Year without a century (00..99)
 *    %Y - Year with century
 *    %Z - Time zone name
 *    %% - Literal ``%'' character
 *     
 *     t = Time.now
 *     t.strftime("Printed on %m/%d/%Y")   #=> "Printed on 04/09/2003"
 *     t.strftime("at %I:%M%p")            #=> "at 08:56AM"
 */

static VALUE
time_strftime(time, format)
    VALUE time, format;
{
    struct time_object *tobj;
    char buffer[SMALLBUF], *buf = buffer;
    const char *fmt;
    long len;
    VALUE str;

    GetTimeval(time, tobj);
    if (tobj->tm_got == 0) {
        time_get_tm(time, tobj->gmt);
    }
    StringValue(format);
    format = rb_str_new4(format);
    fmt = RSTRING(format)->ptr;
    len = RSTRING(format)->len;
    if (len == 0) {
        rb_warning("strftime called with empty format string");
    }
    else if (strlen(fmt) < len) {
        /* Ruby string may contain \0's. */
        const char *p = fmt, *pe = fmt + len;

        str = rb_str_new(0, 0);
        while (p < pe) {
            len = rb_strftime(&buf, p, &tobj->tm);
            rb_str_cat(str, buf, len);
            p += strlen(p) + 1;
            if (buf != buffer) {
                free(buf);
                buf = buffer;
            }
            for (fmt = p; p < pe && !*p; ++p);
            if (p > fmt) rb_str_cat(str, fmt, p - fmt);
        }
        return str;
    }
    else {
        len = rb_strftime(&buf, RSTRING(format)->ptr, &tobj->tm);
    }
    str = rb_str_new(buf, len);
    if (buf != buffer) free(buf);
    return str;
}