+# Copyright (C) 2014-2017 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+package PublicInbox::Reply;
+use strict;
+use warnings;
+use URI::Escape qw/uri_escape_utf8/;
+use PublicInbox::Hval qw/ascii_html/;
+use PublicInbox::Address;
+use PublicInbox::MID qw/mid_clean mid_escape/;
+
+sub squote_maybe ($) {
+ my ($val) = @_;
+ if ($val =~ m{([^\w@\./,\%\+\-])}) {
+ $val =~ s/(['!])/'\\$1'/g; # '!' for csh
+ return "'$val'";
+ }
+ $val;
+}
+
+sub mailto_arg_link {
+ my ($hdr) = @_;
+ my %cc; # everyone else
+ my $to; # this is the From address
+
+ foreach my $h (qw(From To Cc)) {
+ my $v = $hdr->header($h);
+ defined($v) && ($v ne '') or next;
+ my @addrs = PublicInbox::Address::emails($v);
+ foreach my $address (@addrs) {
+ my $dst = lc($address);
+ $cc{$dst} ||= $address;
+ $to ||= $dst;
+ }
+ }
+ my @arg;
+
+ my $subj = $hdr->header('Subject') || '';
+ $subj = "Re: $subj" unless $subj =~ /\bRe:/i;
+ my $mid = $hdr->header_raw('Message-ID');
+ push @arg, '--in-reply-to='.squote_maybe(mid_clean($mid));
+ my $irt = mid_escape($mid);
+ delete $cc{$to};
+ push @arg, "--to=$to";
+ $to = uri_escape_utf8($to);
+ $subj = uri_escape_utf8($subj);
+ my @cc = sort values %cc;
+ push(@arg, map { "--cc=$_" } @cc);
+ my $cc = uri_escape_utf8(join(',', @cc));
+ my $href = "mailto:$to?In-Reply-To=$irt&Cc=${cc}&Subject=$subj";
+
+ (\@arg, ascii_html($href));
+}
+
+1;