From 53a8e32b97985803e9de12c4312a86a8850208b3 Mon Sep 17 00:00:00 2001
From: "Eric W. Biederman" <ebiederm@xmission.com>
Date: Thu, 16 May 2019 19:22:46 -0500
Subject: [PATCH] Config.pm: Add support for mailing list information

The world has turned since I first started following mailing lists and
to my surprise every mailing list that I am subscribed to properly
sets the "List-ID:" mailing list header.  So instead of doing
something clever and flexible I am adding support for looking up
public inbox mailing lists by their mailing list name.

That makes the work needed for each email trivial and easy to understand.
- Parse the "List-ID:" header.
- Lookup in the configuration which mailbox is connected to that
  "List-ID:"
- Deliver the mail to that mailbox.

To that end this change enhances PublicInbox to have an additional
mailbox configuration parameter "listid" that holds the mailing list
name.

A method is added to the PublicInbox config object called
lookup_list_id that given a mailing list name will return the
PublicInbox in the configuration that is configured to handle that
mailing list.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>

[ew: avoid autovivification of $ibx->{listid} for t/config.t]
---
 lib/PublicInbox/Config.pm | 35 ++++++++++++++++++++++++++++++++++-
 1 file changed, 34 insertions(+), 1 deletion(-)

diff --git a/lib/PublicInbox/Config.pm b/lib/PublicInbox/Config.pm
index 4fcb20d2..c2fa40f9 100644
--- a/lib/PublicInbox/Config.pm
+++ b/lib/PublicInbox/Config.pm
@@ -25,6 +25,7 @@ sub new {
 
 	# caches
 	$self->{-by_addr} ||= {};
+	$self->{-by_list_id} ||= {};
 	$self->{-by_name} ||= {};
 	$self->{-by_newsgroup} ||= {};
 	$self->{-no_obfuscate} ||= {};
@@ -84,6 +85,33 @@ sub lookup {
 	_fill($self, $pfx);
 }
 
+sub lookup_list_id {
+	my ($self, $list_id) = @_;
+	$list_id = lc($list_id);
+	my $ibx = $self->{-by_list_id}->{$list_id};
+	return $ibx if $ibx;
+
+	my $pfx;
+
+	foreach my $k (keys %$self) {
+		$k =~ /\A(publicinbox\.[\w-]+)\.listid\z/ or next;
+		my $v = $self->{$k};
+		if (ref($v) eq "ARRAY") {
+			foreach my $alias (@$v) {
+				(lc($alias) eq $list_id) or next;
+				$pfx = $1;
+				last;
+			}
+		} else {
+			(lc($v) eq $list_id) or next;
+			$pfx = $1;
+			last;
+		}
+	}
+	defined $pfx or return;
+	_fill($self, $pfx);
+}
+
 sub lookup_name ($$) {
 	my ($self, $name) = @_;
 	$self->{-by_name}->{$name} || _fill($self, "publicinbox.$name");
@@ -398,7 +426,7 @@ sub _fill {
 	}
 	# TODO: more arrays, we should support multi-value for
 	# more things to encourage decentralization
-	foreach my $k (qw(address altid nntpmirror coderepo hide)) {
+	foreach my $k (qw(address altid nntpmirror coderepo hide listid)) {
 		if (defined(my $v = $self->{"$pfx.$k"})) {
 			$ibx->{$k} = _array($v);
 		}
@@ -421,6 +449,11 @@ sub _fill {
 		$self->{-by_addr}->{$lc_addr} = $ibx;
 		$self->{-no_obfuscate}->{$lc_addr} = 1;
 	}
+	if (my $listids = $ibx->{listid}) {
+		foreach my $list_id (@$listids) {
+			$self->{-by_list_id}->{$list_id} = $ibx;
+		}
+	}
 	if (my $ng = $ibx->{newsgroup}) {
 		$self->{-by_newsgroup}->{$ng} = $ibx;
 	}
-- 
2.44.0