<?php
/**
 * Node Class
 * 
 * Manages router/node configurations within ASNs
 */

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

class Node {
    private FlatFileDB $db;
    private Logger $logger;
    private Validator $validator;
    
    /**
     * Constructor
     * 
     * @param string $dataFile Path to nodes 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();
        
        if (!$this->db->exists('nodes')) {
            $this->db->set('nodes', []);
        }
    }
    
    /**
     * Get all nodes
     * 
     * @return array
     */
    public function getAll(): array {
        return $this->db->get('nodes') ?? [];
    }
    
    /**
     * Get nodes by ASN
     * 
     * @param int $asn
     * @return array
     */
    public function getByAsn(int $asn): array {
        $nodes = $this->db->get('nodes') ?? [];
        return array_filter($nodes, fn($node) => ($node['asn'] ?? 0) === $asn);
    }
    
    /**
     * Get node by ID
     * 
     * @param string $id
     * @return array|null
     */
    public function get(string $id): ?array {
        $nodes = $this->db->get('nodes') ?? [];
        return $nodes[$id] ?? null;
    }
    
    /**
     * Create new node
     * 
     * @param array $data
     * @return array
     */
    public function create(array $data): array {
        $this->validator->clear();
        
        // Validate required fields
        if (empty($data['id'])) {
            return [
                'success' => false,
                'message' => 'Node ID is required',
                'errors' => ['id' => 'Node ID is required'],
            ];
        }
        
        if (empty($data['asn'])) {
            return [
                'success' => false,
                'message' => 'ASN is required',
                'errors' => ['asn' => 'ASN is required'],
            ];
        }
        
        if (!$this->validator->validateAsn($data['asn'], 'asn')) {
            return [
                'success' => false,
                'message' => 'Invalid ASN',
                'errors' => $this->validator->getErrors(),
            ];
        }
        
        $nodes = $this->db->get('nodes') ?? [];
        $id = $this->sanitizeId($data['id']);
        
        if (isset($nodes[$id])) {
            return [
                'success' => false,
                'message' => "Node $id already exists",
                'errors' => ['id' => 'Node ID already exists'],
            ];
        }
        
        // Validate optional fields
        if (!empty($data['router_id']) && !$this->validator->validateRouterId($data['router_id'], 'router_id')) {
            return [
                'success' => false,
                'message' => 'Invalid router ID',
                'errors' => $this->validator->getErrors(),
            ];
        }
        
        $nodeData = [
            'id' => $id,
            'asn' => (int) $data['asn'],
            'name' => $data['name'] ?? $id,
            'hostname' => $data['hostname'] ?? '',
            'router_id' => $data['router_id'] ?? '',
            'description' => $data['description'] ?? '',
            'location' => $data['location'] ?? '',
            'pathvector' => $this->buildPathvectorConfig($data['pathvector'] ?? []),
            'host' => $data['host'] ?? '',
            'templates' => $data['templates'] ?? [],
            'overrides' => $data['overrides'] ?? [],
            'metadata' => $data['metadata'] ?? [],
            'is_active' => $data['is_active'] ?? true,
            'created_at' => date('c'),
            'updated_at' => date('c'),
        ];
        
        $nodes[$id] = $nodeData;
        
        if ($this->db->set('nodes', $nodes)) {
            $this->logger->success('node', "Created node: $id for ASN {$nodeData['asn']}");
            return [
                'success' => true,
                'message' => "Node $id created successfully",
                'data' => $nodeData,
            ];
        }
        
        return [
            'success' => false,
            'message' => 'Failed to save node',
            'errors' => ['database' => 'Failed to save node'],
        ];
    }
    
    /**
     * Update node
     * 
     * @param string $id
     * @param array $data
     * @return array
     */
    public function update(string $id, array $data): array {
        $nodes = $this->db->get('nodes') ?? [];
        
        if (!isset($nodes[$id])) {
            return [
                'success' => false,
                'message' => "Node $id not found",
                'errors' => ['id' => 'Node not found'],
            ];
        }
        
        $nodeData = $nodes[$id];
        
        // Update allowed fields
        $allowedFields = [
            'name', 'hostname', 'router_id', 'description', 'location',
            'host', 'templates', 'overrides', 'metadata', 'is_active'
        ];
        
        foreach ($allowedFields as $field) {
            if (isset($data[$field])) {
                $nodeData[$field] = $data[$field];
            }
        }
        
        // Update Pathvector config
        if (isset($data['pathvector'])) {
            $nodeData['pathvector'] = $this->buildPathvectorConfig(
                array_merge($nodeData['pathvector'], $data['pathvector'])
            );
        }
        
        // Validate router_id if changed
        if (!empty($nodeData['router_id']) && !$this->validator->validateRouterId($nodeData['router_id'], 'router_id')) {
            return [
                'success' => false,
                'message' => 'Invalid router ID',
                'errors' => $this->validator->getErrors(),
            ];
        }
        
        $nodeData['updated_at'] = date('c');
        $nodes[$id] = $nodeData;
        
        if ($this->db->set('nodes', $nodes)) {
            $this->logger->info('node', "Updated node: $id");
            return [
                'success' => true,
                'message' => "Node $id updated successfully",
                'data' => $nodeData,
            ];
        }
        
        return [
            'success' => false,
            'message' => 'Failed to update node',
            'errors' => ['database' => 'Failed to save node'],
        ];
    }
    
    /**
     * Delete node
     * 
     * @param string $id
     * @return array
     */
    public function delete(string $id): array {
        $nodes = $this->db->get('nodes') ?? [];
        
        if (!isset($nodes[$id])) {
            return [
                'success' => false,
                'message' => "Node $id not found",
            ];
        }
        
        $nodeName = $nodes[$id]['name'];
        $nodeAsn = $nodes[$id]['asn'];
        unset($nodes[$id]);
        
        if ($this->db->set('nodes', $nodes)) {
            $this->logger->warning('node', "Deleted node: $id ($nodeName) from ASN $nodeAsn");
            return [
                'success' => true,
                'message' => "Node $id deleted successfully",
            ];
        }
        
        return [
            'success' => false,
            'message' => 'Failed to delete node',
        ];
    }
    
    /**
     * Build Pathvector config structure for a node
     * 
     * @param array $data
     * @return array
     */
    private function buildPathvectorConfig(array $data): array {
        return [
            'binary_path' => $data['binary_path'] ?? '/usr/local/bin/pathvector',
            'config_path' => $data['config_path'] ?? '/etc/pathvector/pathvector.yml',
            'output_path' => $data['output_path'] ?? '/etc/bird/bird.conf',
            'bird_reload_cmd' => $data['bird_reload_cmd'] ?? 'birdc configure',
            'bird_directory' => $data['bird_directory'] ?? '/etc/bird',
            'bird_socket' => $data['bird_socket'] ?? '/var/run/bird.ctl',
            'cache_directory' => $data['cache_directory'] ?? '/var/cache/pathvector',
            
            // Node-specific overrides
            'source4' => $data['source4'] ?? '',
            'source6' => $data['source6'] ?? '',
            'prefixes' => $data['prefixes'] ?? [],
            
            // RPKI settings
            'rpki_enable' => $data['rpki_enable'] ?? true,
            'rtr_server' => $data['rtr_server'] ?? '',
            
            // PeeringDB settings
            'peeringdb_api_key' => $data['peeringdb_api_key'] ?? '',
            'peeringdb_cache' => $data['peeringdb_cache'] ?? true,
            
            // IRR settings
            'irr_server' => $data['irr_server'] ?? 'rr.ntt.net',
            
            // Kernel settings
            'kernel_table' => $data['kernel_table'] ?? null,
            'kernel_learn' => $data['kernel_learn'] ?? false,
            'kernel_export' => $data['kernel_export'] ?? [],
            
            // Global config snippet
            'global_config' => $data['global_config'] ?? '',
            
            // Web UI
            'web_ui_file' => $data['web_ui_file'] ?? '',
            
            // Logging
            'log_file' => $data['log_file'] ?? 'syslog',
        ];
    }
    
    /**
     * Sanitize node ID
     * 
     * @param string $id
     * @return string
     */
    private function sanitizeId(string $id): string {
        // Convert to lowercase, replace spaces with hyphens, remove invalid characters
        $id = strtolower(trim($id));
        $id = preg_replace('/\s+/', '-', $id);
        $id = preg_replace('/[^a-z0-9-_]/', '', $id);
        return $id;
    }
    
    /**
     * Count nodes
     * 
     * @return int
     */
    public function count(): int {
        $nodes = $this->db->get('nodes') ?? [];
        return count($nodes);
    }
    
    /**
     * Count nodes by ASN
     * 
     * @param int $asn
     * @return int
     */
    public function countByAsn(int $asn): int {
        return count($this->getByAsn($asn));
    }
    
    /**
     * Search nodes
     * 
     * @param string $query
     * @return array
     */
    public function search(string $query): array {
        $nodes = $this->db->get('nodes') ?? [];
        $query = strtolower($query);
        
        return array_filter($nodes, function($node) use ($query) {
            return strpos(strtolower($node['id']), $query) !== false ||
                   strpos(strtolower($node['name']), $query) !== false ||
                   strpos(strtolower($node['hostname'] ?? ''), $query) !== false ||
                   strpos(strtolower($node['description'] ?? ''), $query) !== false ||
                   strpos(strtolower($node['location'] ?? ''), $query) !== false;
        });
    }
    
    /**
     * Get nodes by host
     * 
     * @param string $hostId
     * @return array
     */
    public function getByHost(string $hostId): array {
        $nodes = $this->db->get('nodes') ?? [];
        return array_filter($nodes, fn($node) => ($node['host'] ?? '') === $hostId);
    }
    
    /**
     * Export node configuration to YAML
     * 
     * @param string $id
     * @param ASN $asnManager ASN manager for defaults
     * @return string|null
     */
    public function exportYaml(string $id, $asnManager = null): ?string {
        $node = $this->get($id);
        
        if (!$node) {
            return null;
        }
        
        $config = [];
        $config['asn'] = $node['asn'];
        
        if (!empty($node['router_id'])) {
            $config['router-id'] = $node['router_id'];
        }
        
        if (!empty($node['hostname'])) {
            $config['hostname'] = $node['hostname'];
        }
        
        // Pathvector settings
        $pv = $node['pathvector'];
        
        if (!empty($pv['source4'])) {
            $config['source4'] = $pv['source4'];
        }
        
        if (!empty($pv['source6'])) {
            $config['source6'] = $pv['source6'];
        }
        
        if (!empty($pv['prefixes'])) {
            $config['prefixes'] = $pv['prefixes'];
        }
        
        if (!empty($pv['bird_directory'])) {
            $config['bird-directory'] = $pv['bird_directory'];
        }
        
        if (!empty($pv['bird_socket'])) {
            $config['bird-socket'] = $pv['bird_socket'];
        }
        
        if (!empty($pv['cache_directory'])) {
            $config['cache-directory'] = $pv['cache_directory'];
        }
        
        if (isset($pv['rpki_enable'])) {
            $config['rpki-enable'] = $pv['rpki_enable'];
        }
        
        if (!empty($pv['rtr_server'])) {
            $config['rtr-server'] = $pv['rtr_server'];
        }
        
        if (!empty($pv['irr_server'])) {
            $config['irr-server'] = $pv['irr_server'];
        }
        
        if (!empty($pv['global_config'])) {
            $config['global-config'] = $pv['global_config'];
        }
        
        // Apply overrides
        foreach ($node['overrides'] as $key => $value) {
            if ($value !== '' && $value !== null) {
                $config[str_replace('_', '-', $key)] = $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;
                }
                
                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($value, '#') !== false || strpos($value, "\n") !== false)) {
            return '"' . addslashes($value) . '"';
        }
        
        return $value;
    }
    
    /**
     * Backup nodes data
     * 
     * @param string $backupDir
     * @return string|false
     */
    public function backup(string $backupDir): string|false {
        return $this->db->backup($backupDir);
    }
}