"""
VPN Server Management Routes

Provides API endpoints for managing VPN servers and monitoring connections
"""

import logging
from flask import Blueprint, request, jsonify, current_app
from functools import wraps
from models.enhanced_user import User
from services.vpn_server_manager import VPNServerManager
import jwt

logger = logging.getLogger(__name__)

vpn_server_bp = Blueprint('vpn_server', __name__)

def token_required(f):
    """Decorator to require valid JWT token"""
    @wraps(f)
    def decorated(*args, **kwargs):
        token = request.headers.get('Authorization')
        
        if not token:
            return jsonify({'error': 'Token is missing'}), 401
        
        try:
            if token.startswith('Bearer '):
                token = token[7:]
            
            data = jwt.decode(token, current_app.config['SECRET_KEY'], algorithms=['HS256'])
            current_user = User.query.get(data['user_id'])
            
            if not current_user:
                return jsonify({'error': 'Invalid token'}), 401
                
        except jwt.ExpiredSignatureError:
            return jsonify({'error': 'Token has expired'}), 401
        except jwt.InvalidTokenError:
            return jsonify({'error': 'Invalid token'}), 401
        
        return f(current_user, *args, **kwargs)
    
    return decorated

@vpn_server_bp.route('/server/status', methods=['GET'])
@token_required
def get_server_status(current_user):
    """Get VPN server status for all protocols"""
    try:
        vpn_manager = VPNServerManager()
        status = vpn_manager.get_server_status()
        
        return jsonify({
            'success': True,
            'status': status,
            'server_info': vpn_manager.get_server_info()
        })
        
    except Exception as e:
        logger.error(f"Server status error: {e}")
        return jsonify({'error': 'Failed to get server status'}), 500

@vpn_server_bp.route('/server/start/<protocol>', methods=['POST'])
@token_required
def start_server(current_user, protocol):
    """Start VPN server for specified protocol"""
    try:
        # Check if user has admin privileges (for now, allow all authenticated users)
        vpn_manager = VPNServerManager()
        
        if protocol.lower() == 'openvpn':
            success = vpn_manager.start_openvpn_server()
        elif protocol.lower() in ['ikev2', 'ipsec']:
            success = vpn_manager.start_ipsec_server()
        elif protocol.lower() == 'wireguard':
            success = vpn_manager.start_wireguard_server()
        else:
            return jsonify({'error': 'Unsupported protocol'}), 400
        
        if success:
            return jsonify({
                'success': True,
                'message': f'{protocol.upper()} server started successfully'
            })
        else:
            return jsonify({
                'success': False,
                'error': f'Failed to start {protocol.upper()} server'
            }), 500
            
    except Exception as e:
        logger.error(f"Server start error: {e}")
        return jsonify({'error': 'Failed to start server'}), 500

@vpn_server_bp.route('/server/stop/<protocol>', methods=['POST'])
@token_required
def stop_server(current_user, protocol):
    """Stop VPN server for specified protocol"""
    try:
        vpn_manager = VPNServerManager()
        
        if protocol.lower() == 'openvpn':
            success = vpn_manager.stop_openvpn_server()
        elif protocol.lower() in ['ikev2', 'ipsec']:
            success = vpn_manager.stop_ipsec_server()
        elif protocol.lower() == 'wireguard':
            success = vpn_manager.stop_wireguard_server()
        else:
            return jsonify({'error': 'Unsupported protocol'}), 400
        
        if success:
            return jsonify({
                'success': True,
                'message': f'{protocol.upper()} server stopped successfully'
            })
        else:
            return jsonify({
                'success': False,
                'error': f'Failed to stop {protocol.upper()} server'
            }), 500
            
    except Exception as e:
        logger.error(f"Server stop error: {e}")
        return jsonify({'error': 'Failed to stop server'}), 500

@vpn_server_bp.route('/server/restart/<protocol>', methods=['POST'])
@token_required
def restart_server(current_user, protocol):
    """Restart VPN server for specified protocol"""
    try:
        vpn_manager = VPNServerManager()
        
        # Stop server first
        if protocol.lower() == 'openvpn':
            vpn_manager.stop_openvpn_server()
            success = vpn_manager.start_openvpn_server()
        elif protocol.lower() in ['ikev2', 'ipsec']:
            vpn_manager.stop_ipsec_server()
            success = vpn_manager.start_ipsec_server()
        elif protocol.lower() == 'wireguard':
            vpn_manager.stop_wireguard_server()
            success = vpn_manager.start_wireguard_server()
        else:
            return jsonify({'error': 'Unsupported protocol'}), 400
        
        if success:
            return jsonify({
                'success': True,
                'message': f'{protocol.upper()} server restarted successfully'
            })
        else:
            return jsonify({
                'success': False,
                'error': f'Failed to restart {protocol.upper()} server'
            }), 500
            
    except Exception as e:
        logger.error(f"Server restart error: {e}")
        return jsonify({'error': 'Failed to restart server'}), 500

@vpn_server_bp.route('/server/clients/<protocol>', methods=['GET'])
@token_required
def get_connected_clients(current_user, protocol):
    """Get connected clients for specified protocol"""
    try:
        vpn_manager = VPNServerManager()
        status = vpn_manager.get_server_status()
        
        protocol_status = status.get(protocol.lower())
        if not protocol_status:
            return jsonify({'error': 'Unsupported protocol'}), 400
        
        return jsonify({
            'success': True,
            'protocol': protocol.upper(),
            'clients': protocol_status.get('clients', []),
            'client_count': protocol_status.get('client_count', 0),
            'running': protocol_status.get('running', False)
        })
        
    except Exception as e:
        logger.error(f"Connected clients error: {e}")
        return jsonify({'error': 'Failed to get connected clients'}), 500

@vpn_server_bp.route('/server/info', methods=['GET'])
@token_required
def get_server_info(current_user):
    """Get server information for client configuration"""
    try:
        vpn_manager = VPNServerManager()
        server_info = vpn_manager.get_server_info()
        
        return jsonify({
            'success': True,
            'server_info': server_info
        })
        
    except Exception as e:
        logger.error(f"Server info error: {e}")
        return jsonify({'error': 'Failed to get server info'}), 500

@vpn_server_bp.route('/server/protocols', methods=['GET'])
def get_supported_protocols():
    """Get list of supported VPN protocols"""
    try:
        protocols = [
            {
                'name': 'OpenVPN',
                'key': 'openvpn',
                'description': 'Secure, reliable, and widely supported VPN protocol',
                'port': 1194,
                'transport': 'UDP',
                'features': [
                    'Cross-platform compatibility',
                    'Strong encryption (AES-256)',
                    'Certificate-based authentication',
                    'Firewall-friendly'
                ]
            },
            {
                'name': 'IKEv2/IPSec',
                'key': 'ikev2',
                'description': 'Fast and secure protocol, ideal for mobile devices',
                'port': 500,
                'transport': 'UDP',
                'features': [
                    'Excellent mobile support',
                    'Fast reconnection',
                    'Built into most devices',
                    'Strong security'
                ]
            },
            {
                'name': 'WireGuard',
                'key': 'wireguard',
                'description': 'Modern, fast, and lightweight VPN protocol',
                'port': 51820,
                'transport': 'UDP',
                'features': [
                    'Exceptional performance',
                    'Minimal codebase',
                    'Modern cryptography',
                    'Low battery usage'
                ]
            }
        ]
        
        return jsonify({
            'success': True,
            'protocols': protocols
        })
        
    except Exception as e:
        logger.error(f"Protocols info error: {e}")
        return jsonify({'error': 'Failed to get protocols info'}), 500

@vpn_server_bp.route('/server/logs/<protocol>', methods=['GET'])
@token_required
def get_server_logs(current_user, protocol):
    """Get server logs for specified protocol"""
    try:
        lines = request.args.get('lines', 50, type=int)
        lines = min(lines, 1000)  # Limit to 1000 lines max
        
        log_files = {
            'openvpn': '/var/log/openvpn/openvpn.log',
            'ikev2': '/var/log/syslog',  # strongSwan logs to syslog
            'ipsec': '/var/log/syslog',
            'wireguard': '/var/log/syslog'  # WireGuard logs to syslog
        }
        
        log_file = log_files.get(protocol.lower())
        if not log_file:
            return jsonify({'error': 'Unsupported protocol'}), 400
        
        try:
            import subprocess
            
            if protocol.lower() == 'openvpn':
                # Get OpenVPN specific logs
                result = subprocess.run(
                    ['tail', '-n', str(lines), log_file],
                    capture_output=True, text=True
                )
            else:
                # Filter syslog for protocol-specific entries
                if protocol.lower() in ['ikev2', 'ipsec']:
                    grep_pattern = 'charon'
                else:  # wireguard
                    grep_pattern = 'wireguard'
                
                result = subprocess.run(
                    f'grep "{grep_pattern}" {log_file} | tail -n {lines}',
                    shell=True, capture_output=True, text=True
                )
            
            if result.returncode == 0:
                logs = result.stdout.strip().split('\n') if result.stdout.strip() else []
            else:
                logs = []
            
        except Exception:
            logs = []
        
        return jsonify({
            'success': True,
            'protocol': protocol.upper(),
            'logs': logs,
            'line_count': len(logs)
        })
        
    except Exception as e:
        logger.error(f"Server logs error: {e}")
        return jsonify({'error': 'Failed to get server logs'}), 500

@vpn_server_bp.route('/server/statistics', methods=['GET'])
@token_required
def get_server_statistics(current_user):
    """Get comprehensive server statistics"""
    try:
        vpn_manager = VPNServerManager()
        status = vpn_manager.get_server_status()
        
        # Calculate overall statistics
        total_clients = sum(proto.get('client_count', 0) for proto in status.values())
        running_servers = sum(1 for proto in status.values() if proto.get('running', False))
        
        statistics = {
            'overview': {
                'total_clients': total_clients,
                'running_servers': running_servers,
                'total_servers': len(status),
                'server_ip': vpn_manager.server_ip
            },
            'protocols': {}
        }
        
        for protocol, proto_status in status.items():
            statistics['protocols'][protocol] = {
                'running': proto_status.get('running', False),
                'port': proto_status.get('port', 0),
                'client_count': proto_status.get('client_count', 0),
                'clients': proto_status.get('clients', [])
            }
        
        return jsonify({
            'success': True,
            'statistics': statistics
        })
        
    except Exception as e:
        logger.error(f"Server statistics error: {e}")
        return jsonify({'error': 'Failed to get server statistics'}), 500