+# Copyright (C) 2021 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# "lei blob $OID" command
+package PublicInbox::LeiBlob;
+use strict;
+use v5.10.1;
+use parent qw(PublicInbox::IPC);
+use PublicInbox::Spawn qw(spawn popen_rd);
+use PublicInbox::DS;
+use PublicInbox::Eml;
+
+sub sol_done_wait { # dwaitpid callback
+ my ($arg, $pid) = @_;
+ my (undef, $lei) = @$arg;
+ $lei->child_error($?) if $?;
+ $lei->dclose;
+}
+
+sub sol_done { # EOF callback for main daemon
+ my ($lei) = @_;
+ my $sol = delete $lei->{sol} or return;
+ $sol->wq_wait_old(\&sol_done_wait, $lei);
+}
+
+sub get_git_dir ($) {
+ my ($d) = @_;
+ return $d if -d "$d/objects" && -d "$d/refs" && -e "$d/HEAD";
+
+ my $cmd = [ qw(git rev-parse --git-dir) ];
+ my ($r, $pid) = popen_rd($cmd, {GIT_DIR => undef}, { '-C' => $d });
+ chomp(my $gd = do { local $/; <$r> });
+ waitpid($pid, 0) == $pid or die "BUG: waitpid @$cmd ($!)";
+ $? == 0 ? $gd : undef;
+}
+
+sub solver_user_cb { # called by solver when done
+ my ($res, $self) = @_;
+ my $lei = $self->{lei};
+ my $log_buf = delete $lei->{'log_buf'};
+ $$log_buf =~ s/^/# /sgm;
+ ref($res) eq 'ARRAY' or return $lei->fail($$log_buf);
+ $lei->qerr($$log_buf);
+ my ($git, $oid, $type, $size, $di) = @$res;
+ my $gd = $git->{git_dir};
+
+ # don't try to support all the git-show(1) options for non-blob,
+ # this is just a convenience:
+ $type ne 'blob' and
+ $lei->err("# $oid is a $type of $size bytes in:\n#\t$gd");
+
+ my $cmd = [ 'git', "--git-dir=$gd", 'show', $oid ];
+ my $rdr = { 1 => $lei->{1}, 2 => $lei->{2} };
+ waitpid(spawn($cmd, $lei->{env}, $rdr), 0);
+ $lei->child_error($?) if $?;
+}
+
+sub do_solve_blob { # via wq_do
+ my ($self) = @_;
+ my $lei = $self->{lei};
+ my $git_dirs = $lei->{opt}->{'git-dir'};
+ my $hints = {};
+ for my $x (qw(oid-a path-a path-b)) {
+ my $v = $lei->{opt}->{$x} // next;
+ $x =~ tr/-/_/;
+ $hints->{$x} = $v;
+ }
+ open my $log, '+>', \(my $log_buf = '') or die "PerlIO::scalar: $!";
+ $lei->{log_buf} = \$log_buf;
+ my $git = $lei->ale->git;
+ my $solver = bless {
+ gits => [ map {
+ PublicInbox::Git->new($lei->rel2abs($_))
+ } @$git_dirs ],
+ user_cb => \&solver_user_cb,
+ uarg => $self,
+ # -cur_di, -qsp, -msg => temporary fields for Qspawn callbacks
+ inboxes => [ $self->{lxs}->locals ],
+ }, 'PublicInbox::SolverGit';
+ $lei->{env}->{'psgi.errors'} = $lei->{2}; # ugh...
+ local $PublicInbox::DS::in_loop = 0; # waitpid synchronously
+ $solver->solve($lei->{env}, $log, $self->{oid_b}, $hints);
+}
+
+sub lei_blob {
+ my ($lei, $blob) = @_;
+ $lei->start_pager if -t $lei->{1};
+
+ # first, see if it's a blob returned by "lei q" JSON output:
+ my $rdr = { 1 => $lei->{1} };
+ open $rdr->{2}, '>', '/dev/null' or die "open: $!";
+ my $cmd = [ 'git', '--git-dir='.$lei->ale->git->{git_dir},
+ 'cat-file', 'blob', $blob ];
+ waitpid(spawn($cmd, $lei->{env}, $rdr), 0);
+ return if $? == 0;
+
+ # maybe it's a non-email (code) blob from a coderepo
+ my $git_dirs = $lei->{opt}->{'git-dir'} //= [];
+ if ($lei->{opt}->{'cwd'} //= 1) {
+ my $cgd = get_git_dir('.');
+ unshift(@$git_dirs, $cgd) if defined $cgd;
+ }
+ my $lxs = $lei->lxs_prepare or return;
+ require PublicInbox::SolverGit;
+ my $self = bless { lxs => $lxs, oid_b => $blob }, __PACKAGE__;
+ my $op = $lei->workers_start($self, 'lei_solve', 1,
+ { '' => [ \&sol_done, $lei ] });
+ $lei->{sol} = $self;
+ $self->wq_io_do('do_solve_blob', []);
+ $self->wq_close(1);
+ while ($op && $op->{sock}) { $op->event_step }
+}
+
+sub ipc_atfork_child {
+ my ($self) = @_;
+ $self->{lei}->_lei_atfork_child;
+ $SIG{__WARN__} = PublicInbox::Eml::warn_ignore_cb();
+ $self->SUPER::ipc_atfork_child;
+}
+
+1;