<?php
/**
 * ASN Class
 * 
 * Manages ASN (Autonomous System Number) configurations for multi-ASN deployments
 */

require_once __DIR__ . '/FlatFileDB.php';
require_once __DIR__ . '/Logger.php';
require_once __DIR__ . '/Validator.php';

class ASN {
    private FlatFileDB $db;
    private Logger $logger;
    private Validator $validator;
    
    /**
     * Constructor
     * 
     * @param string $dataFile Path to ASNs JSON file
     * @param Logger $logger Logger instance
     */
    public function __construct(string $dataFile, Logger $logger) {
        $this->db = new FlatFileDB($dataFile);
        $this->logger = $logger;
        $this->validator = new Validator();
        
        // Initialize structure
        if (!$this->db->exists('asns')) {
            $this->db->set('asns', []);
        }
    }
    
    /**
     * Get all ASNs
     * 
     * @return array
     */
    public function getAll(): array {
        return $this->db->get('asns') ?? [];
    }
    
    /**
     * Get ASN by ID
     * 
     * @param string $id ASN number as string key
     * @return array|null
     */
    public function get(string $id): ?array {
        $asns = $this->db->get('asns') ?? [];
        return $asns[$id] ?? null;
    }
    
    /**
     * Create new ASN
     * 
     * @param array $data ASN data
     * @return array ['success' => bool, 'message' => string, 'errors' => array]
     */
    public function create(array $data): array {
        $this->validator->clear();
        
        // Validate ASN number
        if (!$this->validator->validateAsn($data['asn'] ?? null, 'asn')) {
            return [
                'success' => false,
                'message' => 'Validation failed',
                'errors' => $this->validator->getErrors(),
            ];
        }
        
        $asns = $this->db->get('asns') ?? [];
        $id = (string) $data['asn'];
        
        // Check if ASN already exists
        if (isset($asns[$id])) {
            return [
                'success' => false,
                'message' => "ASN $id already exists",
                'errors' => ['asn' => 'ASN already exists'],
            ];
        }
        
        // Build ASN entry
        $asnData = [
            'asn' => (int) $data['asn'],
            'name' => $data['name'] ?? "AS{$data['asn']}",
            'description' => $data['description'] ?? '',
            'pathvector_defaults' => $this->buildPathvectorDefaults($data['pathvector_defaults'] ?? []),
            'templates' => $data['templates'] ?? [],
            'contacts' => $data['contacts'] ?? [],
            'metadata' => $data['metadata'] ?? [],
            'created_at' => date('c'),
            'updated_at' => date('c'),
        ];
        
        $asns[$id] = $asnData;
        
        if ($this->db->set('asns', $asns)) {
            $this->logger->success('asn', "Created ASN: $id ({$asnData['name']})");
            return [
                'success' => true,
                'message' => "ASN $id created successfully",
                'data' => $asnData,
            ];
        }
        
        return [
            'success' => false,
            'message' => 'Failed to save ASN',
            'errors' => ['database' => 'Failed to save ASN'],
        ];
    }
    
    /**
     * Update ASN
     * 
     * @param string $id ASN ID
     * @param array $data Updated data
     * @return array
     */
    public function update(string $id, array $data): array {
        $asns = $this->db->get('asns') ?? [];
        
        if (!isset($asns[$id])) {
            return [
                'success' => false,
                'message' => "ASN $id not found",
                'errors' => ['asn' => 'ASN not found'],
            ];
        }
        
        // Merge with existing data
        $asnData = $asns[$id];
        
        if (isset($data['name'])) {
            $asnData['name'] = $data['name'];
        }
        
        if (isset($data['description'])) {
            $asnData['description'] = $data['description'];
        }
        
        if (isset($data['pathvector_defaults'])) {
            $asnData['pathvector_defaults'] = $this->buildPathvectorDefaults(
                array_merge($asnData['pathvector_defaults'], $data['pathvector_defaults'])
            );
        }
        
        if (isset($data['templates'])) {
            $asnData['templates'] = $data['templates'];
        }
        
        if (isset($data['contacts'])) {
            $asnData['contacts'] = $data['contacts'];
        }
        
        if (isset($data['metadata'])) {
            $asnData['metadata'] = array_merge($asnData['metadata'] ?? [], $data['metadata']);
        }
        
        $asnData['updated_at'] = date('c');
        $asns[$id] = $asnData;
        
        if ($this->db->set('asns', $asns)) {
            $this->logger->info('asn', "Updated ASN: $id");
            return [
                'success' => true,
                'message' => "ASN $id updated successfully",
                'data' => $asnData,
            ];
        }
        
        return [
            'success' => false,
            'message' => 'Failed to update ASN',
            'errors' => ['database' => 'Failed to save ASN'],
        ];
    }
    
    /**
     * Delete ASN
     * 
     * @param string $id ASN ID
     * @return array
     */
    public function delete(string $id): array {
        $asns = $this->db->get('asns') ?? [];
        
        if (!isset($asns[$id])) {
            return [
                'success' => false,
                'message' => "ASN $id not found",
            ];
        }
        
        $asnName = $asns[$id]['name'];
        unset($asns[$id]);
        
        if ($this->db->set('asns', $asns)) {
            $this->logger->warning('asn', "Deleted ASN: $id ($asnName)");
            return [
                'success' => true,
                'message' => "ASN $id deleted successfully",
            ];
        }
        
        return [
            'success' => false,
            'message' => 'Failed to delete ASN',
        ];
    }
    
    /**
     * Build Pathvector defaults structure
     * 
     * @param array $data
     * @return array
     */
    private function buildPathvectorDefaults(array $data): array {
        return [
            // Global config
            'router_id' => $data['router_id'] ?? '',
            'source4' => $data['source4'] ?? '',
            'source6' => $data['source6'] ?? '',
            'prefixes' => $data['prefixes'] ?? [],
            'hostname' => $data['hostname'] ?? '',
            
            // BIRD/Pathvector paths
            'bird_directory' => $data['bird_directory'] ?? '/etc/bird',
            'bird_binary' => $data['bird_binary'] ?? '/usr/sbin/bird',
            'bird_socket' => $data['bird_socket'] ?? '/var/run/bird.ctl',
            'cache_directory' => $data['cache_directory'] ?? '/var/cache/pathvector',
            
            // PeeringDB settings
            'peeringdb_query_timeout' => $data['peeringdb_query_timeout'] ?? 10,
            'peeringdb_api_key' => $data['peeringdb_api_key'] ?? '',
            'peeringdb_cache' => $data['peeringdb_cache'] ?? true,
            'peeringdb_url' => $data['peeringdb_url'] ?? 'https://peeringdb.com/api/',
            
            // IRR settings
            'irr_server' => $data['irr_server'] ?? 'rr.ntt.net',
            'irr_query_timeout' => $data['irr_query_timeout'] ?? 30,
            'bgpq_args' => $data['bgpq_args'] ?? '',
            
            // RTR/RPKI settings
            'rtr_server' => $data['rtr_server'] ?? '',
            'rpki_enable' => $data['rpki_enable'] ?? true,
            
            // Filtering defaults
            'keep_filtered' => $data['keep_filtered'] ?? false,
            'merge_paths' => $data['merge_paths'] ?? false,
            'default_route' => $data['default_route'] ?? false,
            'accept_default' => $data['accept_default'] ?? false,
            
            // Communities
            'origin_communities' => $data['origin_communities'] ?? [],
            'local_communities' => $data['local_communities'] ?? [],
            'add_on_import' => $data['add_on_import'] ?? [],
            'add_on_export' => $data['add_on_export'] ?? [],
            
            // Blocklist
            'blocklist' => $data['blocklist'] ?? [],
            'blocklist_urls' => $data['blocklist_urls'] ?? [],
            'blocklist_files' => $data['blocklist_files'] ?? [],
            
            // Bogons
            'bogons4' => $data['bogons4'] ?? [],
            'bogons6' => $data['bogons6'] ?? [],
            'bogon_asns' => $data['bogon_asns'] ?? [],
            'blackhole_bogon_asns' => $data['blackhole_bogon_asns'] ?? false,
            
            // Transit ASNs
            'transit_asns' => $data['transit_asns'] ?? [],
            
            // Operation modes
            'no_announce' => $data['no_announce'] ?? false,
            'no_accept' => $data['no_accept'] ?? false,
            'stun' => $data['stun'] ?? false,
            
            // Global config
            'global_config' => $data['global_config'] ?? '',
            
            // Web UI
            'web_ui_file' => $data['web_ui_file'] ?? '',
            
            // Log
            'log_file' => $data['log_file'] ?? 'syslog',
            
            // Keepalived
            'keepalived_config' => $data['keepalived_config'] ?? '/etc/keepalived.conf',
            
            // Authorized providers (ASPA)
            'authorized_providers' => $data['authorized_providers'] ?? [],
        ];
    }
    
    /**
     * Count ASNs
     * 
     * @return int
     */
    public function count(): int {
        $asns = $this->db->get('asns') ?? [];
        return count($asns);
    }
    
    /**
     * Search ASNs
     * 
     * @param string $query
     * @return array
     */
    public function search(string $query): array {
        $asns = $this->db->get('asns') ?? [];
        $query = strtolower($query);
        
        return array_filter($asns, function($asn) use ($query) {
            return strpos(strtolower((string) $asn['asn']), $query) !== false ||
                   strpos(strtolower($asn['name']), $query) !== false ||
                   strpos(strtolower($asn['description'] ?? ''), $query) !== false;
        });
    }
    
    /**
     * Export ASN to YAML format for Pathvector
     * 
     * @param string $id
     * @return string|null
     */
    public function exportYaml(string $id): ?string {
        $asn = $this->get($id);
        
        if (!$asn) {
            return null;
        }
        
        $config = [];
        $config['asn'] = $asn['asn'];
        
        $defaults = $asn['pathvector_defaults'];
        
        if (!empty($defaults['router_id'])) {
            $config['router-id'] = $defaults['router_id'];
        }
        
        if (!empty($defaults['source4'])) {
            $config['source4'] = $defaults['source4'];
        }
        
        if (!empty($defaults['source6'])) {
            $config['source6'] = $defaults['source6'];
        }
        
        if (!empty($defaults['prefixes'])) {
            $config['prefixes'] = $defaults['prefixes'];
        }
        
        if (!empty($defaults['hostname'])) {
            $config['hostname'] = $defaults['hostname'];
        }
        
        // Add other non-empty defaults
        foreach ($defaults as $key => $value) {
            if ($value !== '' && $value !== [] && $value !== null && !isset($config[$key])) {
                $yamlKey = str_replace('_', '-', $key);
                $config[$yamlKey] = $value;
            }
        }
        
        return $this->arrayToYaml($config);
    }
    
    /**
     * Convert array to YAML string
     * 
     * @param array $data
     * @param int $indent
     * @return string
     */
    private function arrayToYaml(array $data, int $indent = 0): string {
        $yaml = '';
        $prefix = str_repeat('  ', $indent);
        
        foreach ($data as $key => $value) {
            if (is_array($value)) {
                if (empty($value)) {
                    continue;
                }
                
                // Check if it's a sequential array
                if (array_keys($value) === range(0, count($value) - 1)) {
                    $yaml .= "$prefix$key:\n";
                    foreach ($value as $item) {
                        if (is_array($item)) {
                            $yaml .= "$prefix  -\n" . $this->arrayToYaml($item, $indent + 2);
                        } else {
                            $yaml .= "$prefix  - " . $this->formatYamlValue($item) . "\n";
                        }
                    }
                } else {
                    $yaml .= "$prefix$key:\n" . $this->arrayToYaml($value, $indent + 1);
                }
            } else {
                if ($value === '' || $value === null) {
                    continue;
                }
                $yaml .= "$prefix$key: " . $this->formatYamlValue($value) . "\n";
            }
        }
        
        return $yaml;
    }
    
    /**
     * Format value for YAML output
     * 
     * @param mixed $value
     * @return string
     */
    private function formatYamlValue($value): string {
        if (is_bool($value)) {
            return $value ? 'true' : 'false';
        }
        
        if (is_numeric($value)) {
            return (string) $value;
        }
        
        if (is_string($value) && (strpos($value, ':') !== false || strpos($value, '#') !== false)) {
            return '"' . addslashes($value) . '"';
        }
        
        return $value;
    }
    
    /**
     * Backup ASN data
     * 
     * @param string $backupDir
     * @return string|false
     */
    public function backup(string $backupDir): string|false {
        return $this->db->backup($backupDir);
    }
}