<?php
/**
 * Observium
 *
 *   This file is part of Observium.
 *
 * @package    observium
 * @subpackage discovery
 * @copyright  (C) Adam Armstrong
 *
 */

// 'BGP4-MIB', 'CISCO-BGP4-MIB', 'BGP4-V2-MIB-JUNIPER', 'FORCE10-BGP4-V2-MIB', 'ARISTA-BGP4V2-MIB', 'FOUNDRY-BGP4V2-MIB', 'HUAWEI-BGP-VPN-MIB'
if (!$config['enable_bgp'] || !is_device_mib($device, 'BGP4-MIB')) {
    // Note, BGP4-MIB is main MIB, without it, the rest will not be checked
    if ($device['bgpLocalAs']) {
        // FIXME. Clean old discovered peers?
        log_event('BGP Local ASN removed: AS' . $device['bgpLocalAs'], $device, 'device', $device['device_id']);
        dbUpdate([ 'bgpLocalAs' => [ 'NULL' ] ], 'devices', 'device_id = ?', [ $device['device_id'] ]);
        print_cli_data("Updated ASN", $device['bgpLocalAs'] . " -> ''", 2);
    }
    return;
}

// Get Local ASN

// Get an array with existed MIBs on a device with LocasAs-es
$local_as_array = get_bgp_localas_array($device);

$vendor_mib    = FALSE; // CLEANME. Clear after full rewrite to definitions.
$bgpVrfLocalAs = [];
foreach ($local_as_array as $entry) {

    // CLEANME. Clear after full rewrite to definitions.
    if ($entry['mib'] !== 'BGP4-MIB' && $entry['mib'] !== 'CISCO-BGP4-MIB') {
        $vendor_mib = $entry['mib'];
    }

    // LocalAs by first non-zero
    if ($entry['LocalAs'] != 0) {
        if (!isset($bgpLocalAs) &&
            $entry['oid'] !== 'cbgpPeer2LocalAs') {
            // Do not use Cisco Peer LocalAs as device bgp, see https://jira.observium.org/browse/OBS-4116
            $bgpLocalAs = $entry['LocalAs'];
        }
        if (isset($entry['virtual_name']) && !isset($bgpVrfLocalAs[$entry['virtual_name']])) {
            // Set per vrf LocalAs
            $bgpVrfLocalAs[$entry['virtual_name']] = $entry['LocalAs'];
        }
    }
}

// Discover BGP peers

/// NOTE. PeerIdentifier != PeerRemoteAddr

if (is_numeric($bgpLocalAs) && $bgpLocalAs != 0) {
    print_cli_data("Local AS", "AS$bgpLocalAs ", 2);

    // Detect if Local AS changed
    if ($bgpLocalAs != $device['bgpLocalAs']) {
        if (!$device['bgpLocalAs']) {
            log_event('BGP Local ASN added: AS' . $bgpLocalAs, $device, 'device', $device['device_id']);
        } elseif (!$bgpLocalAs) {
            log_event('BGP Local ASN removed: AS' . $device['bgpLocalAs'], $device, 'device', $device['device_id']);
        } else {
            log_event('BGP ASN changed: AS' . $device['bgpLocalAs'] . ' -> AS' . $bgpLocalAs, $device, 'device', $device['device_id']);
        }
        dbUpdate(['bgpLocalAs' => $bgpLocalAs], 'devices', 'device_id = ?', [$device['device_id']]);
        print_cli_data("Updated ASN", $device['bgpLocalAs'] . " -> $bgpLocalAs", 2);
    }

    print_cli_data_field("Caching");

    // Init
    $p_list   = []; // valid_peers
    $peerlist = [];
    $af_list  = [];

    foreach ($local_as_array as $entry) {
        $mib = $entry['mib'];
        echo("$mib ");
        if ($check_vrfs = isset($entry['virtual_name'])) {
            // Keep original
            $device_original     = $device;
            $bgpLocalAs_original = $bgpLocalAs;
            if (isset($bgpVrfLocalAs[$entry['virtual_name']])) {
                // Need in per VRF discovery
                $bgpLocalAs = $bgpVrfLocalAs[$entry['virtual_name']];
            }
            $vrf_name     = $entry['virtual_name'];
            $snmp_virtual = $entry['snmp_context'];
            // Set device for VRF tables
            $device = snmp_virtual_device($device_original, $snmp_virtual);
            echo("(Virtual Routing $vrf_name) ");
        } elseif ($entry['vrf_name']) {
            // only stored VRF name, ie CUMULUS-BGPVRF-MIB
            $vrf_name = $entry['vrf_name'];
            echo("(Virtual Routing $vrf_name) ");
        }

        /* Start caching bgp peers */
        $include = __DIR__ . '/bgp/' . strtolower($mib) . '.inc.php';
        if (!is_file($include)) {
            // Common for vendor mibs
            $include = __DIR__ . '/bgp/bgp4v2-mib.inc.php';
        }
        include $include;
        /* End caching bgp peers */

        if ($check_vrfs) {
            // Restore device array
            $device     = $device_original;
            $bgpLocalAs = $bgpLocalAs_original;
        }
    }

} else {
    echo("No BGP on host");
    if (is_numeric($device['bgpLocalAs'])) {
        log_event('BGP ASN removed: AS' . $device['bgpLocalAs'], $device, 'device', $device['device_id']);
        dbUpdate([ 'bgpLocalAs' => [ 'NULL' ] ], 'devices', 'device_id = ?', [$device['device_id']]);
        print_message('Removed ASN (' . $device['bgpLocalAs'] . ')');
    } # End if
} # End if

// Process discovered peers

global $table_rows;
$table_rows = [];

if (!safe_empty($peerlist)) {
    print_debug_vars($peerlist);

    echo(PHP_EOL);
    // Filter IP search by BGP enabled devices (without self)
    $bgp_device_ids = dbFetchColumn('SELECT `device_id` FROM `devices` WHERE `device_id` != ? AND `bgpLocalAs` > 0 AND `disabled` = 0 AND `status` = 1', [$device['device_id']]);
    $peer_as_where  = generate_query_values_and($bgp_device_ids, 'device_id');

    $peer_devices     = [];
    $peer_devices_ids = [];
    foreach (dbFetchRows('SELECT `device_id`, `bgpPeerLocalAddr`, `bgpPeerRemoteAddr` FROM `bgpPeers` WHERE `bgpPeerRemoteAs` = ?' . $peer_as_where, [$bgpLocalAs]) as $entry) {
        $peer_devices[$entry['bgpPeerLocalAddr']][$entry['bgpPeerRemoteAddr']] = $entry['device_id'];
        $peer_devices_ids[]                                                    = $entry['device_id'];
    }
    print_debug_vars($peer_devices);

    $peer_ip_where = generate_query_values_and($peer_devices_ids, 'device_id') . generate_query_values_and('up', 'ifOperStatus');

    foreach ($peerlist as $peer) {

        $astext      = get_astext($peer['as']);
        $reverse_dns = gethostbyaddr6($peer['ip']);
        if ($reverse_dns == $peer['ip']) {
            $reverse_dns = '';
        }

        // Search a remote device if possible
        $peer_addr_version = get_ip_version($peer['ip']);

        $peer_device_id = get_peer_remote_device_id($peer, $peer_devices, $peer_ip_where);
        $peer_device    = is_numeric($peer_device_id) ? device_by_id_cache($peer_device_id) : [];

        //$peer['local_as']        = (isset($peer['local_as']) && $peer['local_as'] != 0 && $peer['local_as'] != '') ? $peer['local_as'] : $bgpLocalAs;
        $local_as = $peer['local_as'];
        if (isset($peer['virtual_name'])) {
            $local_as .= ' (' . $peer['virtual_name'] . ')';
        }
        $table_rows[$peer['ip']] = [ $local_as, $peer['local_ip'], $peer['as'], $peer['ip'], '', $reverse_dns, truncate($peer_device['hostname'], 30) ];
        $params                  = [
          'device_id'         => $device['device_id'],
          'bgpPeerIdentifier' => $peer['identifier'],
          'bgpPeerRemoteAddr' => $peer['ip'],
          'bgpPeerLocalAddr'  => $peer['local_ip'],
          'local_as'          => $peer['local_as'],
          'bgpPeerRemoteAs'   => $peer['as'],
          'astext'            => $astext,
          'reverse_dns'       => $reverse_dns,
          'virtual_name'      => $peer['virtual_name'] ?? [ 'NULL' ],
          'peer_device_id'    => $peer_device_id ?: [ 'NULL' ]
        ];

        $peer_db = dbFetchRow('SELECT * FROM `bgpPeers` WHERE `device_id` = ? AND `bgpPeerRemoteAddr` = ?', [$device['device_id'], $peer['ip']]);
        if (!safe_empty($peer_db)) {
            $update_array = [];
            foreach ($params as $param => $value) {

                if ($value === ['NULL']) {
                    if ($peer_db[$param] != '') {
                        $update_array[$param] = $value;
                    }
                } elseif ($value != $peer_db[$param]) {
                    $update_array[$param] = $value;
                }
            }

            if ($update_count = count($update_array)) {
                dbUpdate($update_array, 'bgpPeers', '`device_id` = ? AND `bgpPeerRemoteAddr` = ?', [$device['device_id'], $peer['ip']]);
                if (isset($update_array['reverse_dns']) && $update_count === 1) {
                    // Do not count updates if changed only reverse DNS
                    $GLOBALS['module_stats'][$module]['unchanged']++;
                } else {
                    $GLOBALS['module_stats'][$module]['updated']++;
                }
            } else {
                $GLOBALS['module_stats'][$module]['unchanged']++;
            }

            $peer_id = $peer_db['bgpPeer_id'];
        } else {
            $peer_id = dbInsert($params, 'bgpPeers');
            $GLOBALS['module_stats'][$module]['added']++;
        }

        $peer['id']            = $peer_id;
        $peer_ids[$peer['ip']] = $peer_id;

        // AFI/SAFI for specific vendors
        if (isset($peer_afis[$peer['ip']])) {
            $peer_index = $peer['index']; // keep original
            foreach ($peer_afis[$peer['ip']] as $af_entry) {
                $peer['index'] = $af_entry['index'] ?? $peer_index;
                discovery_bgp_afisafi($device, $peer, $af_entry['afi'], $af_entry['safi'], $af_list);
            }
            $peer['index'] = $peer_index; // restore
        }

        // Autodiscovery for bgp neighbours
        if ($config['autodiscovery']['bgp']) {
            if (($peer['as'] == $device['bgpLocalAs']) || // ASN matches local router
                ($config['autodiscovery']['bgp_as_private'] && is_bgp_as_private($peer['as'])) || // ASN is private
                (is_array($config['autodiscovery']['bgp_as_whitelist']) && in_array($peer['as'], $config['autodiscovery']['bgp_as_whitelist']))) { // ASN is in bgp_as_whitelist

                // Try find remote device and check if already cached
                $remote_device_id = get_autodiscovery_device_id($device, $peer['ip']);
                if (is_null($remote_device_id) &&       // NULL - never cached in other rounds
                    check_autodiscovery($peer['ip'])) { // Check all previous autodiscovery rounds
                    // Neighbour never checked, try autodiscover
                    $remote_device_id = autodiscovery_device($peer['ip'], NULL, 'BGP', NULL, $device);
                }
            }
        }
    } # Foreach

    // Remove deleted AFI/SAFI
    unset($afi, $safi, $peer_ip, $peer_id);
    $cbgp_delete = [];
    $query       = 'SELECT * FROM `bgpPeers_cbgp` WHERE `device_id` = ?';
    foreach (dbFetchRows($query, [$device['device_id']]) as $entry) {
        $peer_id = $entry['bgpPeer_id'];
        $afi     = $entry['afi'];
        $safi    = $entry['safi'];
        $cbgp_id = $entry['cbgp_id'];

        if (!isset($af_list[$peer_id][$afi][$safi])) {
            $cbgp_delete[] = $cbgp_id;
            //dbDelete('bgpPeers_cbgp', '`cbgp_id` = ?', array($cbgp_id));
        }
    } # AF list
    if (safe_count($cbgp_delete)) {
        // Multi-delete
        dbDelete('bgpPeers_cbgp', generate_query_values($cbgp_delete, 'cbgp_id'));
    }
    unset($af_list, $cbgp_delete);
} # end peerlist

// Delete removed peers
unset($peer_ip, $peer_as);
$peers_delete = [];
$query        = 'SELECT * FROM `bgpPeers` WHERE `device_id` = ?';
foreach (dbFetchRows($query, [$device['device_id']]) as $entry) {
    $peer_ip = $entry['bgpPeerRemoteAddr'];
    $peer_as = $entry['bgpPeerRemoteAs'];

    if (!isset($p_list[$peer_ip][$peer_as])) {
        // dbDelete('bgpPeers', '`bgpPeer_id` = ?', [ $entry['bgpPeer_id'] ]);
        $peers_delete[] = $entry['bgpPeer_id'];
        $GLOBALS['module_stats'][$module]['deleted']++;
    } else {
        // Unset, for exclude duplicate entries in DB
        unset($p_list[$peer_ip][$peer_as]);
    }
}
if (count($peers_delete)) {
    // Multi-delete
    dbDelete('bgpPeers', generate_query_values($peers_delete, 'bgpPeer_id'));
    dbDelete('bgpPeers_cbgp', generate_query_values($peers_delete, 'bgpPeer_id'));
}

$table_headers = ['%WLocal: AS (VRF)%n', '%WIP%n', '%WPeer: AS%n', '%WIP%n', '%WFamily%n', '%WrDNS%n', '%WRemote Device%n'];
print_cli_table($table_rows, $table_headers);

unset($p_list, $peerlist, $vendor_mib, $cisco_version, $cisco_peers, $table_rows, $table_headers, $peer_devices, $peer_devices_ids);

// EOF