<?php
/**
 * BirdConfig Class
 * 
 * Helper class for BIRD 3 configuration parsing and generation
 */

class BirdConfig {
    
    /**
     * Parse BIRD protocol status output
     * 
     * @param string $output
     * @return array
     */
    public static function parseProtocolStatus(string $output): array {
        $protocols = [];
        $lines = explode("\n", trim($output));
        
        // Skip header lines
        $dataStarted = false;
        
        foreach ($lines as $line) {
            $line = trim($line);
            
            if (empty($line)) {
                continue;
            }
            
            // Skip BIRD header
            if (strpos($line, 'BIRD') === 0 || strpos($line, 'Name') === 0) {
                $dataStarted = true;
                continue;
            }
            
            if (!$dataStarted) {
                continue;
            }
            
            // Parse protocol line
            // Format: Name Proto Table State Since Info
            $parts = preg_split('/\s+/', $line, 6);
            
            if (count($parts) >= 5) {
                $protocols[] = [
                    'name' => $parts[0],
                    'proto' => $parts[1],
                    'table' => $parts[2],
                    'state' => $parts[3],
                    'since' => $parts[4],
                    'info' => $parts[5] ?? '',
                ];
            }
        }
        
        return $protocols;
    }
    
    /**
     * Parse BIRD route count output
     * 
     * @param string $output
     * @return array
     */
    public static function parseRouteCount(string $output): array {
        $counts = [
            'total' => 0,
            'primary' => 0,
            'filtered' => 0,
        ];
        
        // Format: X of Y routes for Z networks
        if (preg_match('/(\d+)\s+of\s+(\d+)\s+routes\s+for\s+(\d+)\s+networks/', $output, $matches)) {
            $counts['primary'] = (int) $matches[1];
            $counts['total'] = (int) $matches[2];
            $counts['networks'] = (int) $matches[3];
        }
        
        // Filtered routes
        if (preg_match('/(\d+)\s+routes\s+\((\d+)\s+filtered\)/', $output, $matches)) {
            $counts['total'] = (int) $matches[1];
            $counts['filtered'] = (int) $matches[2];
        }
        
        return $counts;
    }
    
    /**
     * Parse BIRD status output
     * 
     * @param string $output
     * @return array
     */
    public static function parseStatus(string $output): array {
        $status = [
            'version' => '',
            'router_id' => '',
            'hostname' => '',
            'server_time' => '',
            'last_reboot' => '',
            'last_reconfiguration' => '',
        ];
        
        $lines = explode("\n", trim($output));
        
        foreach ($lines as $line) {
            $line = trim($line);
            
            if (preg_match('/^BIRD\s+(.+)$/', $line, $matches)) {
                $status['version'] = trim($matches[1]);
            } elseif (preg_match('/^Router ID is\s+(.+)$/', $line, $matches)) {
                $status['router_id'] = trim($matches[1]);
            } elseif (preg_match('/^Hostname is\s+(.+)$/', $line, $matches)) {
                $status['hostname'] = trim($matches[1]);
            } elseif (preg_match('/^Current server time is\s+(.+)$/', $line, $matches)) {
                $status['server_time'] = trim($matches[1]);
            } elseif (preg_match('/^Last reboot on\s+(.+)$/', $line, $matches)) {
                $status['last_reboot'] = trim($matches[1]);
            } elseif (preg_match('/^Last reconfiguration on\s+(.+)$/', $line, $matches)) {
                $status['last_reconfiguration'] = trim($matches[1]);
            }
        }
        
        return $status;
    }
    
    /**
     * Parse detailed protocol info
     * 
     * @param string $output
     * @return array
     */
    public static function parseProtocolDetail(string $output): array {
        $info = [
            'name' => '',
            'description' => '',
            'state' => '',
            'table' => '',
            'neighbor_address' => '',
            'neighbor_as' => '',
            'local_as' => '',
            'neighbor_id' => '',
            'routes' => [
                'imported' => 0,
                'exported' => 0,
                'preferred' => 0,
                'filtered' => 0,
            ],
            'uptime' => '',
            'hold_timer' => '',
            'keepalive_timer' => '',
            'last_error' => '',
            'channel' => [],
        ];
        
        $lines = explode("\n", trim($output));
        $currentChannel = null;
        
        foreach ($lines as $line) {
            $line = trim($line);
            
            // Protocol name
            if (preg_match('/^(\S+)\s+BGP\s+/', $line, $matches)) {
                $info['name'] = $matches[1];
            }
            
            // Description
            if (preg_match('/Description:\s+(.+)$/', $line, $matches)) {
                $info['description'] = trim($matches[1]);
            }
            
            // State
            if (preg_match('/BGP state:\s+(\S+)/', $line, $matches)) {
                $info['state'] = $matches[1];
            }
            
            // Neighbor address and AS
            if (preg_match('/Neighbor address:\s+(\S+)/', $line, $matches)) {
                $info['neighbor_address'] = $matches[1];
            }
            
            if (preg_match('/Neighbor AS:\s+(\d+)/', $line, $matches)) {
                $info['neighbor_as'] = (int) $matches[1];
            }
            
            if (preg_match('/Local AS:\s+(\d+)/', $line, $matches)) {
                $info['local_as'] = (int) $matches[1];
            }
            
            if (preg_match('/Neighbor ID:\s+(\S+)/', $line, $matches)) {
                $info['neighbor_id'] = $matches[1];
            }
            
            // Routes
            if (preg_match('/Routes:\s+(\d+)\s+imported,\s+(\d+)\s+exported,\s+(\d+)\s+preferred/', $line, $matches)) {
                $info['routes']['imported'] = (int) $matches[1];
                $info['routes']['exported'] = (int) $matches[2];
                $info['routes']['preferred'] = (int) $matches[3];
            }
            
            if (preg_match('/(\d+)\s+filtered/', $line, $matches)) {
                $info['routes']['filtered'] = (int) $matches[1];
            }
            
            // Hold timer
            if (preg_match('/Hold timer:\s+(\S+)/', $line, $matches)) {
                $info['hold_timer'] = $matches[1];
            }
            
            // Keepalive timer
            if (preg_match('/Keepalive timer:\s+(\S+)/', $line, $matches)) {
                $info['keepalive_timer'] = $matches[1];
            }
            
            // Last error
            if (preg_match('/Last error:\s+(.+)$/', $line, $matches)) {
                $info['last_error'] = trim($matches[1]);
            }
            
            // Channel info
            if (preg_match('/Channel (ipv[46])/', $line, $matches)) {
                $currentChannel = $matches[1];
                $info['channel'][$currentChannel] = [];
            }
            
            if ($currentChannel && preg_match('/State:\s+(\S+)/', $line, $matches)) {
                $info['channel'][$currentChannel]['state'] = $matches[1];
            }
            
            if ($currentChannel && preg_match('/Table:\s+(\S+)/', $line, $matches)) {
                $info['channel'][$currentChannel]['table'] = $matches[1];
            }
        }
        
        return $info;
    }
    
    /**
     * Get state color class for UI
     * 
     * @param string $state
     * @return string
     */
    public static function getStateColorClass(string $state): string {
        return match (strtolower($state)) {
            'established' => 'color-fg-success',
            'up' => 'color-fg-success',
            'start', 'connect', 'active', 'opensent', 'openconfirm' => 'color-fg-attention',
            'idle' => 'color-fg-muted',
            'down' => 'color-fg-danger',
            default => 'color-fg-default',
        };
    }
    
    /**
     * Get state label for UI
     * 
     * @param string $state
     * @return string
     */
    public static function getStateLabel(string $state): string {
        return match (strtolower($state)) {
            'established' => 'Label--success',
            'up' => 'Label--success',
            'start', 'connect', 'active', 'opensent', 'openconfirm' => 'Label--attention',
            'idle' => 'Label--secondary',
            'down' => 'Label--danger',
            default => 'Label--primary',
        };
    }
    
    /**
     * Generate basic BIRD 3 configuration
     * 
     * @param array $config
     * @return string
     */
    public static function generateBasicConfig(array $config): string {
        $bird = "# BIRD 3 Configuration\n";
        $bird .= "# Generated by Pathvector Admin\n\n";
        
        // Router ID
        if (!empty($config['router_id'])) {
            $bird .= "router id {$config['router_id']};\n\n";
        }
        
        // Log
        $bird .= "log syslog all;\n\n";
        
        // Debug
        $bird .= "debug protocols all;\n\n";
        
        // Timeformat
        $bird .= "timeformat protocol iso long;\n\n";
        
        // Protocol device
        $bird .= "protocol device {\n";
        $bird .= "    scan time 10;\n";
        $bird .= "}\n\n";
        
        // Protocol direct
        $bird .= "protocol direct {\n";
        $bird .= "    ipv4;\n";
        $bird .= "    ipv6;\n";
        $bird .= "}\n\n";
        
        // Protocol kernel
        $bird .= "protocol kernel {\n";
        $bird .= "    ipv4 {\n";
        $bird .= "        export all;\n";
        $bird .= "        import all;\n";
        $bird .= "    };\n";
        $bird .= "}\n\n";
        
        $bird .= "protocol kernel {\n";
        $bird .= "    ipv6 {\n";
        $bird .= "        export all;\n";
        $bird .= "        import all;\n";
        $bird .= "    };\n";
        $bird .= "}\n\n";
        
        return $bird;
    }
    
    /**
     * Validate BIRD config syntax (basic)
     * 
     * @param string $config
     * @return array
     */
    public static function validateSyntax(string $config): array {
        $errors = [];
        $warnings = [];
        
        // Check for common issues
        $lines = explode("\n", $config);
        $braceCount = 0;
        $inString = false;
        
        foreach ($lines as $lineNum => $line) {
            $lineNum++; // 1-indexed
            
            // Skip comments
            if (preg_match('/^\s*#/', $line)) {
                continue;
            }
            
            // Count braces
            for ($i = 0; $i < strlen($line); $i++) {
                $char = $line[$i];
                
                if ($char === '"' && ($i === 0 || $line[$i - 1] !== '\\')) {
                    $inString = !$inString;
                }
                
                if (!$inString) {
                    if ($char === '{') {
                        $braceCount++;
                    } elseif ($char === '}') {
                        $braceCount--;
                    }
                }
            }
            
            // Check for missing semicolons (basic check)
            $trimmed = trim($line);
            if (!empty($trimmed) && 
                !preg_match('/[{};#]$/', $trimmed) && 
                !preg_match('/^\s*(protocol|filter|function|table|if|else|for|case|switch)/', $trimmed)) {
                $warnings[] = "Line $lineNum: Possible missing semicolon";
            }
        }
        
        if ($braceCount !== 0) {
            $errors[] = "Unbalanced braces: " . ($braceCount > 0 ? "missing $braceCount closing braces" : "extra " . abs($braceCount) . " closing braces");
        }
        
        return [
            'valid' => empty($errors),
            'errors' => $errors,
            'warnings' => $warnings,
        ];
    }
    
    /**
     * Format BIRD configuration
     * 
     * @param string $config
     * @return string
     */
    public static function formatConfig(string $config): string {
        $lines = explode("\n", $config);
        $output = [];
        $indent = 0;
        
        foreach ($lines as $line) {
            $trimmed = trim($line);
            
            // Decrease indent for closing braces
            if (preg_match('/^}/', $trimmed)) {
                $indent = max(0, $indent - 1);
            }
            
            // Add line with proper indentation
            if (!empty($trimmed)) {
                $output[] = str_repeat("\t", $indent) . $trimmed;
            } else {
                $output[] = '';
            }
            
            // Increase indent for opening braces
            if (preg_match('/{\s*$/', $trimmed)) {
                $indent++;
            }
        }
        
        return implode("\n", $output);
    }
    
    /**
     * Get list of BIRD 3 protocol types
     * 
     * @return array
     */
    public static function getProtocolTypes(): array {
        return [
            'bgp' => 'Border Gateway Protocol',
            'ospf' => 'Open Shortest Path First',
            'rip' => 'Routing Information Protocol',
            'babel' => 'Babel Routing Protocol',
            'static' => 'Static Routes',
            'kernel' => 'Kernel Route Table',
            'device' => 'Device Protocol',
            'direct' => 'Direct Interfaces',
            'pipe' => 'Table Pipe',
            'bfd' => 'Bidirectional Forwarding Detection',
            'rpki' => 'Resource Public Key Infrastructure',
            'mrt' => 'MRT Table Dump',
        ];
    }
    
    /**
     * Get BGP session states
     * 
     * @return array
     */
    public static function getBgpStates(): array {
        return [
            'Idle' => 'Not running',
            'Connect' => 'Connecting to peer',
            'Active' => 'Trying to connect',
            'OpenSent' => 'Open message sent',
            'OpenConfirm' => 'Waiting for keepalive',
            'Established' => 'Session established',
        ];
    }
}