# Copyright (C) 2018-2019 all contributors
# License: AGPL-3.0+
# Various date/time-related functions
package PublicInbox::MsgTime;
use strict;
use warnings;
use base qw(Exporter);
our @EXPORT_OK = qw(msg_timestamp msg_datestamp);
use Time::Local qw(timegm);
my @MoY = qw(january february march april may june
july august september october november december);
my %MoY;
@MoY{@MoY} = (0..11);
@MoY{map { substr($_, 0, 3) } @MoY} = (0..11);
my %OBSOLETE_TZ = ( # RFC2822 4.3 (Obsolete Date and Time)
EST => '-0500', EDT => '-0400',
CST => '-0600', CDT => '-0500',
MST => '-0700', MDT => '-0600',
PST => '-0800', PDT => '-0700',
UT => '+0000', GMT => '+0000', Z => '+0000',
# RFC2822 states:
# The 1 character military time zones were defined in a non-standard
# way in [RFC822] and are therefore unpredictable in their meaning.
);
my $OBSOLETE_TZ = join('|', keys %OBSOLETE_TZ);
sub str2date_zone ($) {
my ($date) = @_;
my ($ts, $zone);
# RFC822 is most likely for email, but we can tolerate an extra comma
# or punctuation as long as all the data is there.
# We'll use '\s' since Unicode spaces won't affect our parsing.
# SpamAssassin ignores commas and redundant spaces, too.
if ($date =~ /(?:[A-Za-z]+,?\s+)? # day-of-week
([0-9]+),?\s+ # dd
([A-Za-z]+)\s+ # mon
([0-9]{2,4})\s+ # YYYY or YY (or YYY :P)
([0-9]+)[:\.] # HH:
((?:[0-9]{2})|(?:\s?[0-9])) # MM
(?:[:\.]((?:[0-9]{2})|(?:\s?[0-9])))? # :SS
\s+ # a TZ offset is required:
([\+\-])? # TZ sign
[\+\-]* # I've seen extra "-" e.g. "--500"
([0-9]+|$OBSOLETE_TZ)(?:\s|$) # TZ offset
/xo) {
my ($dd, $m, $yyyy, $hh, $mm, $ss, $sign, $tz) =
($1, $2, $3, $4, $5, $6, $7, $8);
# don't accept non-English months
defined(my $mon = $MoY{lc($m)}) or return;
if (defined(my $off = $OBSOLETE_TZ{$tz})) {
$sign = substr($off, 0, 1);
$tz = substr($off, 1);
}
# Y2K problems: 3-digit years, follow RFC2822
if (length($yyyy) <= 3) {
$yyyy += 1900;
# and 2-digit years from '09 (2009) (0..49)
$yyyy += 100 if $yyyy < 1950;
}
$ts = timegm($ss // 0, $mm, $hh, $dd, $mon, $yyyy);
# 4-digit dates in non-spam from 1900s and 1910s exist in
# lore archives
return if $ts < 0;
# Compute the time offset from [+-]HHMM
$tz //= 0;
my ($tz_hh, $tz_mm);
if (length($tz) == 1) {
$tz_hh = $tz;
$tz_mm = 0;
} elsif (length($tz) == 2) {
$tz_hh = 0;
$tz_mm = $tz;
} else {
$tz_hh = $tz;
$tz_hh =~ s/([0-9]{2})\z//;
$tz_mm = $1;
}
while ($tz_mm >= 60) {
$tz_mm -= 60;
$tz_hh += 1;
}
$sign //= '+';
my $off = $sign . ($tz_mm * 60 + ($tz_hh * 60 * 60));
$ts -= $off;
$sign = '+' if $off == 0;
$zone = sprintf('%s%02d%02d', $sign, $tz_hh, $tz_mm);
# Time::Zone and Date::Parse are part of the same distibution,
# and we need Time::Zone to deal with tz names like "EDT"
} elsif (eval { require Date::Parse }) {
$ts = Date::Parse::str2time($date);
return undef unless(defined $ts);
# off is the time zone offset in seconds from GMT
my ($ss,$mm,$hh,$day,$month,$year,$off) =
Date::Parse::strptime($date);
return undef unless(defined $off);
# Compute the time zone from offset
my $sign = ($off < 0) ? '-' : '+';
my $hour = abs(int($off / 3600));
my $min = ($off / 60) % 60;
# deal with weird offsets like '-0420' properly
$min = 60 - $min if ($min && $off < 0);
$zone = sprintf('%s%02d%02d', $sign, $hour, $min);
} else {
warn "Date::Parse missing for non-RFC822 date: $date\n";
return undef;
}
# Note: we've already applied the offset to $ts at this point,
# but we want to keep "git fsck" happy.
# "-1200" is the furthest westermost zone offset,
# but git fast-import is liberal so we use "-1400"
if ($zone >= 1400 || $zone <= -1400) {
warn "bogus TZ offset: $zone, ignoring and assuming +0000\n";
$zone = '+0000';
}
[$ts, $zone];
}
sub time_response ($) {
my ($ret) = @_;
wantarray ? @$ret : $ret->[0];
}
sub msg_received_at ($) {
my ($hdr) = @_; # Email::MIME::Header
my @recvd = $hdr->header_raw('Received');
my ($ts);
foreach my $r (@recvd) {
$r =~ /\s*([0-9]+\s+[a-zA-Z]+\s+[0-9]{2,4}\s+
[0-9]+[^0-9][0-9]+(?:[^0-9][0-9]+)
\s+([\+\-][0-9]+))/sx or next;
$ts = eval { str2date_zone($1) } and return $ts;
my $mid = $hdr->header_raw('Message-ID');
warn "no date in $mid Received: $r\n";
}
undef;
}
sub msg_date_only ($) {
my ($hdr) = @_; # Email::MIME::Header
my @date = $hdr->header_raw('Date');
my ($ts);
foreach my $d (@date) {
$ts = eval { str2date_zone($d) } and return $ts;
if ($@) {
my $mid = $hdr->header_raw('Message-ID');
warn "bad Date: $d in $mid: $@\n";
}
}
undef;
}
# Favors Received header for sorting globally
sub msg_timestamp ($) {
my ($hdr) = @_; # Email::MIME::Header
my $ret;
$ret = msg_received_at($hdr) and return time_response($ret);
$ret = msg_date_only($hdr) and return time_response($ret);
wantarray ? (time, '+0000') : time;
}
# Favors the Date: header for display and sorting within a thread
sub msg_datestamp ($) {
my ($hdr) = @_; # Email::MIME::Header
my $ret;
$ret = msg_date_only($hdr) and return time_response($ret);
$ret = msg_received_at($hdr) and return time_response($ret);
wantarray ? (time, '+0000') : time;
}
1;