#!/usr/bin/env python3
"""
Peer Registry for Personal Internet Cell
Handles peer registration and management
"""

import json
import os
import logging
from threading import RLock
from datetime import datetime
from typing import Dict, List, Any, Optional
from base_service_manager import BaseServiceManager

logger = logging.getLogger(__name__)

class PeerRegistry(BaseServiceManager):
    """Manages peer registration and management"""
    
    def __init__(self, data_dir: str = '/app/data', config_dir: str = '/app/config'):
        super().__init__('peer_registry', data_dir, config_dir)
        self.lock = RLock()
        self.peers = []
        self.peers_file = os.path.join(data_dir, 'peers.json')
        self._load_peers()

    def get_status(self) -> Dict[str, Any]:
        """Get peer registry status"""
        try:
            with self.lock:
                status = {
                    'running': True,
                    'status': 'online',
                    'peers_count': len(self.peers),
                    'active_peers': len([p for p in self.peers if p.get('active', True)]),
                    'inactive_peers': len([p for p in self.peers if not p.get('active', True)]),
                    'last_updated': datetime.utcnow().isoformat(),
                    'timestamp': datetime.utcnow().isoformat()
                }
            
            return status
        except Exception as e:
            return self.handle_error(e, "get_status")

    def test_connectivity(self) -> Dict[str, Any]:
        """Test peer registry connectivity"""
        try:
            # Test file system access
            fs_test = self._test_filesystem_access()
            
            # Test peer data integrity
            integrity_test = self._test_data_integrity()
            
            # Test peer operations
            operations_test = self._test_peer_operations()
            
            results = {
                'filesystem_access': fs_test,
                'data_integrity': integrity_test,
                'peer_operations': operations_test,
                'success': fs_test.get('success', False) and integrity_test.get('success', False),
                'timestamp': datetime.utcnow().isoformat()
            }
            
            return results
        except Exception as e:
            return self.handle_error(e, "test_connectivity")

    def _test_filesystem_access(self) -> Dict[str, Any]:
        """Test filesystem access for peer data"""
        try:
            # Test if we can read/write to the peers file
            test_peer = {
                'peer': 'test_peer',
                'ip': '192.168.1.100',
                'public_key': 'test_key',
                'active': False,
                'test': True
            }
            
            # Test write
            with self.lock:
                original_peers = self.peers.copy()
                self.peers.append(test_peer)
                self._save_peers()
            
            # Test read
            with self.lock:
                loaded_peers = self.peers.copy()
                # Remove test peer
                self.peers = [p for p in self.peers if not p.get('test', False)]
                self._save_peers()
            
            # Restore original state
            with self.lock:
                self.peers = original_peers
                self._save_peers()
            
            return {
                'success': True,
                'message': 'Filesystem access working',
                'read_write': True
            }
        except Exception as e:
            return {
                'success': False,
                'message': f'Filesystem access failed: {str(e)}',
                'error': str(e)
            }

    def _test_data_integrity(self) -> Dict[str, Any]:
        """Test peer data integrity"""
        try:
            with self.lock:
                # Check if peers data is valid JSON
                peers_copy = self.peers.copy()
                
                # Validate peer structure
                valid_peers = 0
                invalid_peers = 0
                
                for peer in peers_copy:
                    if isinstance(peer, dict) and 'peer' in peer and 'ip' in peer:
                        valid_peers += 1
                    else:
                        invalid_peers += 1
                
                return {
                    'success': True,
                    'message': 'Data integrity check passed',
                    'valid_peers': valid_peers,
                    'invalid_peers': invalid_peers,
                    'total_peers': len(peers_copy)
                }
        except Exception as e:
            return {
                'success': False,
                'message': f'Data integrity check failed: {str(e)}',
                'error': str(e)
            }

    def _test_peer_operations(self) -> Dict[str, Any]:
        """Test peer operations"""
        try:
            # Test adding a peer
            test_peer = {
                'peer': 'test_operation_peer',
                'ip': '192.168.1.101',
                'public_key': 'test_operation_key',
                'active': False,
                'test': True
            }
            
            # Test add
            add_success = self.add_peer(test_peer)
            
            # Test get
            retrieved_peer = self.get_peer('test_operation_peer')
            get_success = retrieved_peer is not None
            
            # Test update
            update_success = self.update_peer_ip('test_operation_peer', '192.168.1.102')
            
            # Test remove
            remove_success = self.remove_peer('test_operation_peer')
            
            return {
                'success': add_success and get_success and update_success and remove_success,
                'message': 'Peer operations working',
                'add_success': add_success,
                'get_success': get_success,
                'update_success': update_success,
                'remove_success': remove_success
            }
        except Exception as e:
            return {
                'success': False,
                'message': f'Peer operations test failed: {str(e)}',
                'error': str(e)
            }

    def _load_peers(self):
        """Load peers from file"""
        try:
            # Ensure directory exists
            os.makedirs(os.path.dirname(self.peers_file), exist_ok=True)
            
            if os.path.exists(self.peers_file):
                with open(self.peers_file, 'r') as f:
                    try:
                        self.peers = json.load(f)
                        self.logger.info(f"Loaded {len(self.peers)} peers from file")
                    except Exception as e:
                        self.logger.error(f"Error loading peers: {e}")
                        self.peers = []
                # Phase 3 migration: per-peer internet routing
                changed = False
                for peer in self.peers:
                    if 'route_via' not in peer:
                        peer['route_via'] = None
                        changed = True
                if changed:
                    self._save_peers()
            else:
                self.peers = []
                self.logger.info("No peers file found, starting with empty registry")
        except Exception as e:
            self.logger.error(f"Error in _load_peers: {e}")
            self.peers = []

    def _save_peers(self):
        """Save peers to file"""
        try:
            # Ensure directory exists
            os.makedirs(os.path.dirname(self.peers_file), exist_ok=True)

            # Write to a temp file with restrictive perms, then atomically replace.
            # peers.json contains WireGuard private keys — must never be world-readable.
            tmp_path = self.peers_file + '.tmp'
            # Open with O_CREAT|O_WRONLY|O_TRUNC and mode 0o600 so the file is
            # created with restrictive permissions from the very first byte.
            fd = os.open(tmp_path, os.O_WRONLY | os.O_CREAT | os.O_TRUNC, 0o600)
            try:
                with os.fdopen(fd, 'w') as f:
                    json.dump(self.peers, f, indent=2)
            except Exception:
                try:
                    os.unlink(tmp_path)
                except OSError:
                    pass
                raise
            # Ensure perms are 0o600 even if umask or prior file affected them.
            os.chmod(tmp_path, 0o600)
            os.replace(tmp_path, self.peers_file)
            # Belt-and-braces: also chmod the destination in case it pre-existed
            # with looser perms on a filesystem that preserves the destination's mode.
            os.chmod(self.peers_file, 0o600)

            self.logger.info(f"Saved {len(self.peers)} peers to file")
        except Exception as e:
            self.logger.error(f"Error saving peers: {e}")

    def list_peers(self) -> List[Dict[str, Any]]:
        """List all peers"""
        with self.lock:
            return list(self.peers)

    def get_peer(self, name: str) -> Optional[Dict[str, Any]]:
        """Get a specific peer by name"""
        with self.lock:
            for peer in self.peers:
                if peer.get('peer') == name:
                    return peer
            return None

    def add_peer(self, peer_info: Dict[str, Any]) -> bool:
        """Add a new peer"""
        try:
            with self.lock:
                if self.get_peer(peer_info.get('peer')):
                    self.logger.warning(f"Peer {peer_info.get('peer')} already exists")
                    return False
                
                # Add timestamp
                peer_info['created_at'] = datetime.utcnow().isoformat()
                peer_info['active'] = peer_info.get('active', True)
                
                self.peers.append(peer_info)
                self._save_peers()
                
                self.logger.info(f"Added peer: {peer_info.get('peer')}")
                return True
        except Exception as e:
            self.logger.error(f"Error adding peer: {e}")
            return False

    def remove_peer(self, name: str) -> bool:
        """Remove a peer"""
        try:
            with self.lock:
                before = len(self.peers)
                self.peers = [p for p in self.peers if p.get('peer') != name]
                self._save_peers()
                
                removed = len(self.peers) < before
                if removed:
                    self.logger.info(f"Removed peer: {name}")
                else:
                    self.logger.warning(f"Peer {name} not found for removal")
                
                return removed
        except Exception as e:
            self.logger.error(f"Error removing peer {name}: {e}")
            return False

    def update_peer(self, name: str, fields: Dict[str, Any]) -> bool:
        """Update arbitrary fields on a peer."""
        try:
            with self.lock:
                for peer in self.peers:
                    if peer.get('peer') == name:
                        peer.update(fields)
                        peer['updated_at'] = datetime.utcnow().isoformat()
                        self._save_peers()
                        self.logger.info(f"Updated peer {name}: {list(fields.keys())}")
                        return True
                self.logger.warning(f"Peer {name} not found for update")
                return False
        except Exception as e:
            self.logger.error(f"Error updating peer {name}: {e}")
            return False

    def clear_reinstall_flag(self, name: str) -> bool:
        """Clear the config_needs_reinstall flag after user downloads new config."""
        return self.update_peer(name, {'config_needs_reinstall': False})

    def update_peer_ip(self, name: str, new_ip: str) -> bool:
        """Update peer IP address"""
        try:
            with self.lock:
                for peer in self.peers:
                    if peer.get('peer') == name:
                        old_ip = peer.get('ip')
                        peer['ip'] = new_ip
                        peer['updated_at'] = datetime.utcnow().isoformat()
                        self._save_peers()
                        
                        self.logger.info(f"Updated peer {name} IP from {old_ip} to {new_ip}")
                        return True
                
                self.logger.warning(f"Peer {name} not found for IP update")
                return False
        except Exception as e:
            self.logger.error(f"Error updating peer {name} IP: {e}")
            return False

    def set_route_via(self, peer_name: str, via_cell: Optional[str]) -> Dict[str, Any]:
        """Set or clear the route_via field on a peer. Returns the updated peer dict."""
        with self.lock:
            for peer in self.peers:
                if peer.get('peer') == peer_name:
                    peer['route_via'] = via_cell
                    peer['updated_at'] = datetime.utcnow().isoformat()
                    self._save_peers()
                    self.logger.info(f"Set route_via for {peer_name}: {via_cell!r}")
                    return dict(peer)
        raise ValueError(f"Peer '{peer_name}' not found")

    def get_peer_stats(self) -> Dict[str, Any]:
        """Get peer registry statistics"""
        try:
            with self.lock:
                active_peers = [p for p in self.peers if p.get('active', True)]
                inactive_peers = [p for p in self.peers if not p.get('active', True)]
                
                # Count peers by IP range
                ip_ranges = {}
                for peer in self.peers:
                    ip = peer.get('ip', '')
                    if ip:
                        range_key = '.'.join(ip.split('.')[:3]) + '.0/24'
                        ip_ranges[range_key] = ip_ranges.get(range_key, 0) + 1
                
                return {
                    'total_peers': len(self.peers),
                    'active_peers': len(active_peers),
                    'inactive_peers': len(inactive_peers),
                    'ip_ranges': ip_ranges,
                    'timestamp': datetime.utcnow().isoformat()
                }
        except Exception as e:
            self.logger.error(f"Error getting peer stats: {e}")
            return {
                'total_peers': 0,
                'active_peers': 0,
                'inactive_peers': 0,
                'ip_ranges': {},
                'error': str(e),
                'timestamp': datetime.utcnow().isoformat()
            }