#!/usr/bin/perl
# Internal bridge to Proxmox's notification and cluster configuration libraries.
use strict;
use warnings;
use JSON;
use PVE::Cluster;
use PVE::DataCenterConfig;
use PVE::INotify;
use PVE::Notify;
use PVE::Tools;

my $json = JSON->new->canonical;
my $policy_file = '/etc/pve/priv/tapm-update-policy.json';
my $receipts_file = '/etc/pve/priv/tapm-update-receipts.json';

sub read_json {
    my ($path) = @_;
    return {} if !-e $path;
    return $json->decode(PVE::Tools::file_get_contents($path));
}

sub snapshot {
    PVE::Cluster::cfs_update();
    my $dc = PVE::Cluster::cfs_read_file('datacenter.cfg');
    return { policy => read_json($policy_file), notify => $dc->{notify} // {} };
}

sub locked {
    my ($code) = @_;
    my $result;
    PVE::Cluster::cfs_lock_domain('tapm-update-notifications', 10, sub {
        $result = $code->();
    });
    die $@ if $@;
    return $result;
}

my $result;
my $ok = eval {
    die "root required" if $> != 0;
    PVE::INotify::inotify_init();
    my $input = do { local $/; <STDIN> };
    my $request = $json->decode($input);
    my $action = $request->{action} // '';
    if ($action eq 'read') {
        $result = snapshot();
    } elsif ($action eq 'apply') {
        $result = locked(sub {
            my $current = snapshot();
            die "configuration changed" if $json->encode($current) ne $json->encode($request->{expected});
            my $policy = $request->{policy};
            die "invalid mode" if ($policy->{mode} // '') !~ /\A(?:all|version|disabled)\z/;
            die "invalid owner" if ($policy->{owner} // '') !~ /\A[A-Za-z0-9][A-Za-z0-9.-]{0,62}\z/;
            my $response;
            PVE::Cluster::cfs_lock_file('datacenter.cfg', 10, sub {
                my $dc = PVE::Cluster::cfs_read_file('datacenter.cfg');
                die "notification settings changed" if $json->encode($dc->{notify} // {}) ne $json->encode($current->{notify});
                # Preserve all unrelated notification options and datacenter settings.
                my $before = $json->decode($json->encode($dc));
                PVE::Tools::file_set_contents('/etc/pve/priv/tapm-update-policy.previous.json', $json->encode($current));
                $dc->{notify} //= {};
                $dc->{notify}->{'package-updates'} = $policy->{mode} eq 'all' ? 'always' : 'never';
                PVE::Cluster::cfs_write_file('datacenter.cfg', $dc);
                eval { PVE::Tools::file_set_contents($policy_file, $json->encode($policy)); };
                if (my $err = $@) {
                    PVE::Cluster::cfs_write_file('datacenter.cfg', $before);
                    die $err;
                }
                $response = { applied => JSON::true };
            });
            die $@ if $@;
            return $response;
        });
    } elsif ($action eq 'send') {
        $result = locked(sub {
            my $current = snapshot();
            my $policy = $current->{policy};
            # An old scheduler must not send after a policy/owner change.
            return { sent => JSON::false } if ($policy->{mode} // '') ne 'version'
                || ($policy->{owner} // '') ne PVE::INotify::nodename()
                || ($policy->{generation} // '') ne ($request->{generation} // '')
                || ($current->{notify}->{'package-updates'} // '') ne 'never';
            my $node = $request->{node};
            die "invalid node" if ($node // '') !~ /\A[A-Za-z0-9][A-Za-z0-9.-]{0,62}\z/;
            for my $key (qw(installed available)) {
                die "invalid version" if ($request->{$key} // '') !~ /\A[0-9][A-Za-z0-9.+:~\-]{0,100}\z/;
            }
            my $receipts = read_json($receipts_file);
            # Keep history so repository switches do not re-announce an old candidate.
            return { sent => JSON::false } if $receipts->{$node}->{$request->{available}};
            my $data = { hostname => $node, installed => $request->{installed}, available => $request->{available} };
            PVE::Notify::info('tapm-pve-version', $data, { type => 'package-updates', hostname => $node });
            $receipts->{$node}->{$request->{available}} = time();
            PVE::Tools::file_set_contents($receipts_file, $json->encode($receipts));
            return { sent => JSON::true };
        });
    } else {
        die "unknown operation";
    }
    1;
};
if (!$ok) {
    # Do not expose package names, credentials or raw backend errors in output.
    print STDERR "Proxmox notification operation failed; verify cluster quorum, configuration and notification delivery.\n";
    exit 1;
}
print $json->encode($result), "\n";