# Copyright (C) 2014-2020 all contributors
# License: AGPL-3.0+
# two-step linkification.
# intended usage is in the following order:
#
# linkify_1
#
# linkify_2
#
# Maybe this could be done more efficiently...
package PublicInbox::Linkify;
use strict;
use warnings;
use Digest::SHA qw/sha1_hex/;
use PublicInbox::Hval qw(ascii_html mid_href);
use PublicInbox::MID qw($MID_EXTRACT);
my $SALT = rand;
my $LINK_RE = qr{([\('!])?\b((?:ftps?|https?|nntps?|imaps?|s?news|gopher)://
[\@:\w\.-]+(?:/
(?:[a-z0-9\-\._~!\$\&\';\(\)\*\+,;=:@/%]*)
(?:\?[a-z0-9\-\._~!\$\&\';\(\)\*\+,;=:@/%]+)?
(?:\#[a-z0-9\-\._~!\$\&\';\(\)\*\+,;=:@/%\?]+)?
)?
)}xi;
sub new { bless {}, $_[0] }
# try to distinguish paired punctuation chars from the URL itself
# Maybe other languages/formats can be supported here, too...
my %pairs = (
"(" => qr/(\)[\.,;\+]?)\z/, # Markdown (,), Ruby (+) (, for arrays)
"'" => qr/('[\.,;\+]?)\z/, # Perl / Ruby
"!" => qr/(![\.,;\+]?)\z/, # Perl / Ruby
);
sub linkify_1 {
$_[1] =~ s^$LINK_RE^
my $beg = $1 || '';
my $url = $2;
my $end = '';
# it's fairly common to end URLs in messages with
# '.', ',' or ';' to denote the end of a statement;
# assume the intent was to end the statement/sentence
# in English
if (defined(my $re = $pairs{$beg})) {
if ($url =~ s/$re//) {
$end = $1;
}
} elsif ($url =~ s/(\))?([\.,;])\z//) {
$end = $2;
# require ')' to be paired with '('
if (defined $1) { # ')'
if (index($url, '(') < 0) {
$end = ")$end";
} else {
$url .= ')';
}
}
} elsif ($url !~ /\(/ && $url =~ s/\)\z//) {
$end = ')';
}
$url = ascii_html($url); # for IDN
# salt this, as this could be exploited to show
# links in the HTML which don't show up in the raw mail.
my $key = sha1_hex($url . $SALT);
$_[0]->{$key} = $url;
$beg . 'PI-LINK-'. $key . $end;
^geo;
$_[1];
}
sub linkify_2 {
# Added "PI-LINK-" prefix to avoid false-positives on git commits
$_[1] =~ s!\bPI-LINK-([a-f0-9]{40})\b!
my $key = $1;
my $url = $_[0]->{$key};
if (defined $url) {
"$url";
} else {
# false positive or somebody tried to mess with us
$key;
}
!ge;
$_[1];
}
# single pass linkification of within $str
# with $pfx being the URL prefix
sub linkify_mids {
my ($self, $pfx, $str, $raw) = @_;
$$str =~ s!$MID_EXTRACT!
my $mid = $1;
my $html = ascii_html($mid);
my $href = mid_href($mid);
# salt this, as this could be exploited to show
# links in the HTML which don't show up in the raw mail.
my $key = sha1_hex($html . $SALT);
my $repl = qq(<$html>);
$repl .= qq{ (raw)} if $raw;
$self->{$key} = $repl;
'PI-LINK-'. $key;
!ge;
$$str = ascii_html($$str);
$$str =~ s!\bPI-LINK-([a-f0-9]{40})\b!
my $key = $1;
my $repl = $_[0]->{$key};
if (defined $repl) {
$repl;
} else {
# false positive or somebody tried to mess with us
$key;
}
!ge;
}
sub to_html { linkify_2($_[0], ascii_html(linkify_1(@_))) }
1;