lei ls-mail-source: list IMAP folders and NNTP groups

While other tools can provide the same functionality, having
integration with git-credential is convenient, here.  Caching
and completion will be implemented separately.

4 files changed, 94 insertions, 8 deletions

diff --git a/lib/PublicInbox/LEI.pm b/lib/PublicInbox/LEI.pm
index d34997fd..833d9c4d 100644
--- a/lib/PublicInbox/LEI.pm
+++ b/lib/PublicInbox/LEI.pm
@@ -196,6 +196,8 @@ our %CMD = ( # sorted in order of importance/use:
 'ls-label' => [ '', 'list labels', qw(z|0 stats:s), @c_opt ],
 'ls-mail-sync' => [ '[FILTER]', 'list mail sync folders',
                 qw(z|0 globoff|g invert-match|v local remote), @c_opt ],
+'ls-mail-source' => [ 'URL', 'list IMAP or NNTP mail source folders',
+                qw(z|0 ascii l), @c_opt ],
 'forget-external' => [ 'LOCATION...|--prune',
         'exclude further results from a publicinbox|extindex',
         qw(prune), @c_opt ],
@@ -381,6 +383,7 @@ my %OPTDESC = (
 'format|f=s        ls-search' => ['OUT|json|jsonl|concatjson',
                         'listing output format' ],
 'l        ls-search' => 'long listing format',
+'l        ls-mail-source' => 'long listing format',
 'format|f=s        ls-external' => $ls_format,
 
 'limit|n=i@' => ['NUM', 'limit on number of matches (default: 10000)' ],
diff --git a/lib/PublicInbox/LeiInput.pm b/lib/PublicInbox/LeiInput.pm
index 24211bf0..92d67715 100644
--- a/lib/PublicInbox/LeiInput.pm
+++ b/lib/PublicInbox/LeiInput.pm
@@ -229,7 +229,7 @@ sub prepare_inputs { # returns undef on error
                 if ($input =~ m!\A(?:imaps?|nntps?|s?news)://!i) {
                         require PublicInbox::NetReader;
                         $net //= PublicInbox::NetReader->new;
-                        $net->add_url($input);
+                        $net->add_url($input, $self->{-ls_ok});
                         push @{$sync->{ok}}, $input if $sync;
                 } elsif ($input_path =~ m!\Ahttps?://!i) { # mboxrd.gz
                         # TODO: how would we detect r/w JMAP?
diff --git a/lib/PublicInbox/LeiLsMailSource.pm b/lib/PublicInbox/LeiLsMailSource.pm
new file mode 100644
index 00000000..e95c0b34
--- /dev/null
+++ b/lib/PublicInbox/LeiLsMailSource.pm
@@ -0,0 +1,82 @@
+# Copyright (C) 2021 all contributors <meta@public-inbox.org>
+# License: AGPL-3.0+ <https://www.gnu.org/licenses/agpl-3.0.txt>
+
+# command for listing NNTP groups and IMAP folders,
+# handy for users with git-credential-helper configured
+# TODO: list JMAP labels
+package PublicInbox::LeiLsMailSource;
+use strict;
+use v5.10.1;
+use parent qw(PublicInbox::IPC PublicInbox::LeiInput);
+
+sub input_path_url { # overrides LeiInput version
+        my ($self, $url) = @_;
+        # TODO: support ndjson and other JSONs we support elsewhere
+        my $json;
+        my $lei = $self->{lei};
+        my $ORS = "\n";
+        if ($self->{lei}->{opt}->{l}) {
+                $json = ref(PublicInbox::Config->json)->new->utf8->canonical;
+                $json->ascii(1) if $lei->{opt}->{ascii};
+        } elsif ($self->{lei}->{opt}->{z}) {
+                $ORS = "\0";
+        }
+        if ($url =~ m!\Aimaps?://!i) {
+                my $uri = PublicInbox::URIimap->new($url);
+                my $mic = $lei->{net}->mic_get($uri);
+                my $l = $mic->folders_hash($uri->path); # server-side filter
+                if ($json) {
+                        $lei->puts($json->encode($l));
+                } else {
+                        $lei->out(join($ORS, (map { $_->{name} } @$l), ''));
+                }
+        } elsif ($url =~ m!\A(?:nntps?|s?news)://!i) {
+                my $uri = PublicInbox::URInntps->new($url);
+                my $nn = $lei->{net}->nn_get($uri);
+                my $l = $nn->newsgroups($uri->group); # name => description
+                if ($json) {
+                        my $all = $nn->list;
+                        my @x;
+                        for my $ng (sort keys %$l) {
+                                my $desc = $l->{$ng};
+
+# we need to drop CR ourselves iff using IO::Socket::SSL since
+# Net::Cmd::getline doesn't get used by Net::NNTP if TLS is in play, noted in:
+# <https://rt.cpan.org/Ticket/Display.html?id=129966>
+                                $desc =~ s/\r\z//;
+
+                                my ($hwm, $lwm, $status) = @{$all->{$ng}};
+                                push @x, { name => $ng, lwm => $lwm + 0,
+                                        hwm => $hwm + 0, status => $status,
+                                        description => $desc };
+                        }
+                        $lei->puts($json->encode(\@x));
+                } else {
+                        $lei->out(join($ORS, sort(keys %$l), ''));
+                }
+        } else { die "BUG: $url not supported" }
+}
+
+sub lei_ls_mail_source {
+        my ($lei, $url, $pfx) = @_;
+        $url =~ m!\A(?:imaps?|nntps?|s?news)://!i or return
+                $lei->fail('only NNTP and IMAP URLs supported');
+        my $self = bless { pfx => $pfx, -ls_ok => 1 }, __PACKAGE__;
+        $self->prepare_inputs($lei, [ $url ]) or return;
+        $lei->start_pager if -t $lei->{1};
+        my $ops = {};
+        $lei->{auth}->op_merge($ops, $self);
+        my $j = $self->{-wq_nr_workers} = 1; # locked
+        (my $op_c, $ops) = $lei->workers_start($self, $j, $ops);
+        $lei->{wq1} = $self;
+        $lei->{-err_type} = 'non-fatal';
+        net_merge_all_done($self) unless $lei->{auth};
+        $lei->wait_wq_events($op_c, $ops); # net_merge_all_done if !{auth}
+}
+
+no warnings 'once';
+*ipc_atfork_child = \&PublicInbox::LeiInput::input_only_atfork_child;
+*net_merge_all_done = \&PublicInbox::LeiInput::input_only_net_merge_all_done;
+*net_merge_all = \&PublicInbox::LeiAuth::net_merge_all;
+
+1;
diff --git a/lib/PublicInbox/NetReader.pm b/lib/PublicInbox/NetReader.pm
index 2795a9d4..bcc6cbf0 100644
--- a/lib/PublicInbox/NetReader.pm
+++ b/lib/PublicInbox/NetReader.pm
@@ -236,18 +236,19 @@ W: see https://rt.cpan.org/Ticket/Display.html?id=129967 for updates
 }
 
 sub imap_uri {
-        my ($url) = @_;
+        my ($url, $ls_ok) = @_;
         require PublicInbox::URIimap;
         my $uri = PublicInbox::URIimap->new($url);
-        $uri ? $uri->canonical : undef;
+        $uri && ($ls_ok || $uri->mailbox) ? $uri->canonical : undef;
 }
 
 my %IS_NNTP = (news => 1, snews => 1, nntp => 1, nntps => 1);
 sub nntp_uri {
-        my ($url) = @_;
+        my ($url, $ls_ok) = @_;
         require PublicInbox::URInntps;
         my $uri = PublicInbox::URInntps->new($url);
-        $uri && $IS_NNTP{$uri->scheme} && $uri->group ? $uri->canonical : undef;
+        $uri && $IS_NNTP{$uri->scheme} && ($ls_ok || $uri->group) ?
+                $uri->canonical : undef;
 }
 
 sub cfg_intvl ($$$) {
@@ -367,11 +368,11 @@ sub nntp_common_init ($;$) {
 }
 
 sub add_url {
-        my ($self, $arg) = @_;
+        my ($self, $arg, $ls_ok) = @_;
         my $uri;
-        if ($uri = imap_uri($arg)) {
+        if ($uri = imap_uri($arg, $ls_ok)) {
                 push @{$self->{imap_order}}, $uri;
-        } elsif ($uri = nntp_uri($arg)) {
+        } elsif ($uri = nntp_uri($arg, $ls_ok)) {
                 push @{$self->{nntp_order}}, $uri;
         } else {
                 push @{$self->{unsupported_url}}, $arg;