--- /dev/null
+# Copyright (C) 2021 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# lcat: local cat, display a local message by Message-ID or blob,
+# extracting from URL necessary
+# "lei lcat <URL|SPEC>"
+package PublicInbox::LeiLcat;
+use strict;
+use v5.10.1;
+use PublicInbox::LeiViewText;
+use URI::Escape qw(uri_unescape);
+use URI;
+use PublicInbox::MID qw($MID_EXTRACT);
+
+sub lcat_redispatch {
+ my ($lei, $out, $op_p) = @_;
+ my $l = bless { %$lei }, ref($lei);
+ delete $l->{sock};
+ $l->{''} = $op_p; # daemon only
+ eval {
+ $l->qerr("# updating $out");
+ up1($l, $out);
+ $l->qerr("# $out done");
+ };
+ $l->err($@) if $@;
+}
+
+sub extract_1 ($$) {
+ my ($lei, $x) = @_;
+ if ($x =~ m!\b([a-z]+?://\S+)!i) {
+ my $u = $1;
+ $u =~ s/[\>\]\)\,\.\;]+\z//;
+ $u = URI->new($u);
+ my $p = $u->path;
+ my $term;
+ if ($p =~ m!([^/]+\@[^/]+)!) { # common msgid pattern
+ $term = 'mid:'.uri_unescape($1);
+
+ # is it a URL which returns the full thread?
+ if ($u->scheme =~ /\Ahttps?/i &&
+ $p =~ m!/(?:T/?|t/?|t\.mbox\.gz|t\.atom)\b!) {
+
+ $lei->{mset_opt}->{threads} = 1;
+ }
+ } elsif ($u->scheme =~ /\Ahttps?/i &&
+ # some msgids don't have '@', see if it looks like
+ # a public-inbox URL:
+ $p =~ m!/([^/]+)/(raw|t/?|T/?|
+ t\.mbox\.gz|t\.atom)\z!x) {
+ $lei->{mset_opt}->{threads} = 1 if $2 && $2 ne 'raw';
+ $term = 'mid:'.uri_unescape($1);
+ }
+ $term;
+ } elsif ($x =~ $MID_EXTRACT) { # <$MSGID>
+ "mid:$1";
+ } elsif ($x =~ /\b((?:m|mid):\S+)/) { # our own prefixes (and mairix)
+ $1;
+ } elsif ($x =~ /\bid:(\S+)/) { # notmuch convention
+ "mid:$1";
+ } else {
+ undef;
+ }
+}
+
+sub extract_all {
+ my ($lei, @argv) = @_;
+ my $strict = !$lei->{opt}->{stdin};
+ my @q;
+ for my $x (@argv) {
+ if (my $term = extract_1($lei,$x)) {
+ push @q, $term;
+ } elsif ($strict) {
+ return $lei->fail(<<"");
+could not extract Message-ID from $x
+
+ }
+ }
+ @q ? join(' OR ', @q) : $lei->fail("no Message-ID in: @argv");
+}
+
+sub _stdin { # PublicInbox::InputPipe::consume callback for --stdin
+ my ($lei) = @_; # $_[1] = $rbuf
+ if (defined($_[1])) {
+ $_[1] eq '' and return eval {
+ if (my $dfd = $lei->{3}) {
+ chdir($dfd) or return $lei->fail("fchdir: $!");
+ }
+ my @argv = split(/\s+/, $lei->{mset_opt}->{qstr});
+ $lei->{mset_opt}->{qstr} = extract_all($lei, @argv)
+ or return;
+ $lei->_start_query;
+ };
+ $lei->{mset_opt}->{qstr} .= $_[1];
+ } else {
+ $lei->fail("error reading stdin: $!");
+ }
+}
+
+sub lei_lcat {
+ my ($lei, @argv) = @_;
+ my $lxs = $lei->lxs_prepare or return;
+ $lei->ale->refresh_externals($lxs);
+ my $sto = $lei->_lei_store(1);
+ $lei->{lse} = $sto->search;
+ my $opt = $lei->{opt};
+ my %mset_opt = map { $_ => $opt->{$_} } qw(threads limit offset);
+ $mset_opt{asc} = $opt->{'reverse'} ? 1 : 0;
+ $mset_opt{limit} //= 10000;
+ $opt->{sort} //= 'relevance';
+ $mset_opt{relevance} = 1;
+ $lei->{mset_opt} = \%mset_opt;
+ $opt->{'format'} //= 'mboxrd' unless defined($opt->{output});
+ if ($lei->{opt}->{stdin}) {
+ return $lei->fail(<<'') if @argv;
+no args allowed on command-line with --stdin
+
+ require PublicInbox::InputPipe;
+ PublicInbox::InputPipe::consume($lei->{0}, \&_stdin, $lei);
+ return;
+ }
+ $lei->{mset_opt}->{qstr} = extract_all($lei, @argv) or return;
+ $lei->_start_query;
+}
+
+1;